# Tool Post Holder



## mickri

I have bunch of atlas/craftsman tool holders for a lantern style tool post holder.  I don't care much for the lantern style tool post holders and use my 4 way most of the time.  Got to thinking why not make a 4 way sized to hold my atlas/craftsman tool holders.  In researching how to make a 4 way this evening I came across a very interesting easy to make QCTP holder.



The attached pdf's describes how to make it.  I am thinking about making one   Has anybody used one of these?


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## ch2co

Very well done!  Impressive. 
I never liked lantern type holders either. Fortunately my used lathe came with a quick release tool post.


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## Eddyde

Never seen that one before. A step up from a lantern no doubt but perhaps not quite as versatile as a Aloris style QCTP as it doesn't index to a set position (other than height). However, it can be made easily can cheaply so that is an advantage.


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## Ray C

Very nice.  Looks like you turned the sides on your lathe.  Good job.

One last thing to consider...  get a hand file and break the edges.   If you crack you knuckles on that thing, you'll be bleeding.

Great job....

Ray


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## mickri

I have not made one yet.   Please don't give me credit for something I have not done. The picture is from the web site where I found the article on how to make it.   I think that I will add it to the project list.


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## Ray C

mickri said:


> I have not made one yet.   Please don't give me credit for something I have not done. The picture is from the web site where I found the article on how to make it.   I think that I will add it to the project list.



Ahhh, OK.  If that's the case, stop talking and get to work...


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## T Bredehoft

Yes, I've used these, have one made just for threading. others for boring. Good Job.


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## mickri

Been going over the plans for what I would need to make one of these.  Eddyde commented that it doesn't index except for height.   Being a newby to machining I have no experience with indexable tool holders.  I understand the concept however don't know the practical of how an indexable tool post holder works.  Could someone enlighten me on this.  Or point me to a plan/drawing of an indexable tool post holder.

Thanks


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## mickri

Found a you tube video where a guy made one of these for his mini lathe.






And I found a you tube video that showed how the indexing on a 4 way tool post holder worked.  So I have figured out how to make one of these tool post holders indexable.  I have some of the steel that I need and will order the rest.


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## ericc

The tool post in the article seems to be missing the integral base that is in the photo and video.  It is an easy mod, it appears.


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## mickri

In looking at additional plans for this type of tool post holder I learned that it was originally patented in the 1890's by a machinist named Norman and this style of tool post holder is sometimes referred to as a "norman style" tool post holder.  Just a little bit of trivia that I thought to share.

Changing the subject a little.   I was looking at my 4 way tool post holder and thought why couldn't I add a height adjustment screw like the one's used in the norman style tool post holder.  This would eliminate the need for shims.  Seems like a reasonable solution to shimming.  Am I missing something here.


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## francist

I'm not seeing how that would work. The Norman style is able to use the height adjustment screw because the tool holders slide up and down on the substantial centre column which gives the stability. An ordinary 4-way bolts straight to the compound without a central pillar, so an adjustment screw is not going to make for a very stable setup. 

Or perhaps I am the one who is missing something?

-frank


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## extropic

In addition to what francist wrote, there is very little chance (essentially zero chance) that four different tools in a 4WTP will have the same cutting height.
That's why you need to shim each cutter individually.


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## mickri

My 4 way has a center column that it rotates around so I don't think that is a problem.  Whether it is substantial enough I don't know. 
 The different heights of cutting tools is definitely an issue.  If the height adjusting screw is truly easy to use couldn't you just adjust the height for each tool.  One article that I read suggested scribing a line at center height on the tailstock ram to facilitate easy height adjustment.  I don't know if that is practical or not.
My biggest concern is what happens when you tighten the nut that locks the 4 way in place.  With only one adjusting screw I would think that the 4 way would cock when you lock it in place.  I think that you would need at least 3, maybe 4, adjusting screws.  Get the height set with one screw and then lightly tighten the others to match.  

Being new to this I don't know the answers to my questions.  I appreciate your comments.


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## francist

That's what I was getting at with the one screw -- cocking the thing off to one side when it was tightened. I think that's the beauty of the Norman is that the screw just sets elevation, all the clamping force appears to in that nice snug-fitting bore/column arrangement. And the column, being as fat as it is, should be very stiff.

That being said, I don't own a Norman style. Just run of the mill 4-way, 3-way that use a simple bolt and T-nut to the compound.

-frank


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## mickri

I might give this a try with 3 adjusting screws.  I looked at my 4 way and I can put in 3 screws that won't interfere with anything.   I could also put in 4 screws if I wanted to.  If I don't like or it doesn't work I can always remove them.


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## kd4gij

When I was using my 4 way TP. When I shimmed a tool I super glued the shims to the bottom of the tool. Work out great.

I used cheap feeler gauges for the shims.


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## T Bredehoft

extropic said:


> essentially zero chance) that four different tools in a 4WTP will have the same cutting height



I built my 4 tool holder to hold 3/8 and 3/4 tools flush on to centerline of the spindle. I have inserts to use 5/16, 1/4 and 3/16 tools, no shims,s just spacers made to fit.

_Edit:_ Correct typo


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## kd4gij

extropic said:


> In addition to what francist wrote, there is very little chance (essentially zero chance) that four different tools in a 4WTP will have the same cutting height.
> That's why you need to shim each cutter individually.




 With the 4 way I have 1/2"  insert tools all sit on center. 1/2" brazed carbide also set on center until I reground the tip.


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## mickri

Thanks for all the suggestions on using my 4 way.  I will give them a try.  I am going to make a norman style tool post holder to fit all of the craftsman tool holders that came with my lathe.  Just waiting to get the 1 1/4" x 2" x 1' flat steel bar to make the holders.  I have the rest of the materials that I need to make the post and base.  Time to get started.


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## extropic

extropic said:


> In addition to what francist wrote, there is very little chance (essentially zero chance) that four different tools in a 4WTP will have the same cutting height.
> That's why you need to shim each cutter individually.



The comments that my earlier reply has motivated makes it clear that I made too many assumptions and also didn't specify a detailed description of what type of 4WTP we were discussing. Francisist referred to "An ordinary 4-way bolts straight to the compound without a central pillar (snip)". That's the kind I was talking about.

The ideas of using only indexable insert tooling and/or only new (not resharpened) brazed carbide bits and/or a custom design 4 Way didn't occur to me. I guess they should have. My reply was based on the use of various sizes and grinds of HSS bits which, in my experience, are very common.

Whether you call shims spacers or spacers shims, isn't the function the same?


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## T Bredehoft

extropic said:


> Whether you call shims spacers or spacers shims, isn't the function the same?



I guess "shims" brings forth stacks of shim stock to make the correct height. My spacers are one piece of 4140 ht, .750 by .750 by 1.50 with a .187 by .187 (or whatever) relief to accept the proper tool and place it under the screws that hold it in place. I also have a spacer than holds a .090 wide hollow ground cut off tool at the correct height, ditto knurling tool.


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## mickri

I find everyone's comments interesting and educational.  Thanks for sharing

  In furthering my knowledge on tool post holders I came across several threads on how people had made their lantern's easier to use.  Mostly by replacing the typical rocker and the spacer it sits on with a spacer machined to give the correct angle and/or height to place a cutting tool at centerline.  As an experiment I put one of my craftsman tool holders in my lantern without the rocker and the spacer turned upside down and checked to see how far off it was from being on centerline.  I was surprised to find that it was exactly on centerline.  I tried a couple of others and they all were on centerline.  The only one that wasn't on centerline was the parting tool.  It was a little below center.  In one of the boxes of tooling that came with my lathe there was a bunch of shims and spacers.  I tried a couple and found a spacer that brought my parting tool up to being on centerline. 

I only use my lantern for parting and threading and always dreaded these tasks because it was such a PITA to setup the lantern.  While still not being as easy as a qctp it will be much easier now to use my lantern when I need it.


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## mickri

I have started making this tool post holder.  In looking at my 4 way and a boring bar holder I have they both have a protrusion on the bottom that fits into the slot on the compound.  One, I am concerned that I do not have the skill to make the protrusion precise enough to closely fit in the slot and be square with the slot, and two, that I will be able to get the hole for the "T" post precisely in the center of this protrusion.  I am also going to drill holes in the base at 30 degree spacing so that the tool holder can be indexed with the height adjustment screw.   Would 15 degree spacing be better?   I will be making the base on my mill/drill.  Here is a sketch of the base.


I am thinking about not having the protrusion.   Without the protrusion each time I mount the tool holder on the compound I would have to square it to the face of the chuck.   I think that this will be better for me.  I am concerned that without a tight fit and if the holes aren't precisely inline with the protrusion the tool holder won't be square to the axis of the lathe.   Am I over thinking this?

As for indexing off of the height adjustment screw my plan is to either bevel the end of the screw with a corresponding bevel in the index holes or turn down the end of the index screw to fit in the holes.


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## T Bredehoft

For years, I, as a professional Tool & Die maker, eyeballed square for the QCTH. In other words, it isn't critical.


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## mickri

The post is done and the only thing left to do on the base is to make indents for the height adjustment screw to sit in so the tool holder would be indexable.  I was thinking of making the indents every 30 degrees.  I think that I could also make them every 15 degrees.  The only question I have on indexing concerns threading.  Everything that I have read on threading says to have the compound set at either 29 or 29.5 degrees for threading.  How would you achieve this if the tool post holder is indexed at 30 degree intervals.  Do you square the tool post holder to the face of the chuck with the compound set at 29.5 degrees?

Another question.  I have thought of drilling  1/8" holes in the base and turning the end of the height adjustment screw down to 1/8" to fit in the hole.  Or should I use a drill to make a shallow dent in the base with the end of the height adjustment screw turned to match that angle?  Or should I use a different angle say 60 degrees?  Or a combination of both?


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## homebrewed

Early on I removed the indexing pin on my tool holder, and have yet to have a problem when I turn stuff.  It may be this is partially due to the fact that I'm using a 7x12 lathe and don't take heavy cuts, so the cutter angle(s) are not as critical.  The QCTP I made has no indexing feature.

For threading, the tool is square to the work.  The tool path follows the 29.5 degree angle.  You can do this by setting the compound to 29.5 degrees, or simulating that by setting the compound to zero degrees and using a combination of cross slide + compound moves.  IIRC, if you move the cross slide by "x", you move the compound by "2*x".  This IS an approximation--instead of the 29.5 degree path it's 26.6 degrees, an error of 2.9 degrees.  Ideally you'd move the compound by 1.77*x but that's not so easy to do in your head.  But if you insist on an indexing feature, this approach doesn't require anything special to accommodate the 29.5 degree angle.....and would be a piece of cake if you happen to own a CNC lathe.


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## mickri

Here is a picture of the base and post on the compound.  I have not tried do make any dents in the base for indexing.




It is very solid and square to the compound.

The only reason I thought to make it indexable is because of comments above that this style of tool post holder was not indexable implying that it would be better if it was indexable.  Making it indexable does add complexity because every tool holder you make has to be identical in all respects.  To be honest I probably don't have the skill to do that.  The main reason I am making this qctp is to not have to use the lantern tool post.  I primarily use 4 different tools.  RH turning, parting, threading, and boring.  It will be very convenient to have a tool holder for each.  I will probably make a separate holder for each of the 3 boring bars, 1/4, 3/8 & 1/2, that I use most often.  And several separate holders for normal HSS and the altas/craftsman tool holders for a lantern tool post that came with my lathe.

Now on to making the holders.


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## pacifica

mickri said:


> The post is done and the only thing left to do on the base is to make indents for the height adjustment screw to sit in so the tool holder would be indexable.  I was thinking of making the indents every 30 degrees.  I think that I could also make them every 15 degrees.  The only question I have on indexing concerns threading.  Everything that I have read on threading says to have the compound set at either 29 or 29.5 degrees for threading.  How would you achieve this if the tool post holder is indexed at 30 degree intervals.  Do you square the tool post holder to the face of the chuck with the compound set at 29.5 degrees?
> 
> Another question.  I have thought of drilling  1/8" holes in the base and turning the end of the height adjustment screw down to 1/8" to fit in the hole.  Or should I use a drill to make a shallow dent in the base with the end of the height adjustment screw turned to match that angle?  Or should I use a different angle say 60 degrees?  Or a combination of both?


I know it isnt the recommended way, but I lock the compound and thread straight in, no 29 degrees business.
With a retractable toolholder , I reverse the carriage and dont have to worry about finding my place for depth on the next cut,thread depth calculations are more straight forward since you are not advancing at an angle.. When you are doing 10 or more cuts it is easier for me.


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## Winegrower

I hope everybody considering a four way will check out the inexpensive wedge type QCTP and holders available from many sources, say for example,, CDCO tools.   The capability and ease of use, coupled with the low cost of more holders and styles (boring, knurling, etc.) are hard to beat.


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## kd4gij

Winegrower said:


> I hope everybody considering a four way will check out the inexpensive wedge type QCTP and holders available from many sources, say for example,, CDCO tools.   The capability and ease of use, coupled with the low cost of more holders and styles (boring, knurling, etc.) are hard to beat.




Why do you discourage using a 4 way.


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## jdedmon91

kd4gij said:


> Why do you discourage using a 4 way.



I don’t know what OP thoughts was. Mine is the simplicity of getting the tools set and kept set. I have so many tools that are set on center and it is too handy


Sent from my iPhone using Tapatalk


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## mickri

I wondered that too.  I like my 4 way even if it is really a 2 or 3 way when you get right down to it.  I was actually researching how to make a 4 way to fit the atlas/craftsman tool holders that came with my lathe when I ran across the plans to make a norman style qctp.  The tool post holder I am making didn't seem any harder to make than a 4 way.  So here I am.  Of course this is just a hobby for me and it doesn't really matter how long it takes me to do something.  Would be a different story if I was trying to make a living.


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## kd4gij

I have an aloris QCTP on one lathe and a 4 way on the other. In production the 4 way is faster and more ridged.  Either one is a great choice.


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## Winegrower

Yes I could imagine for some repetitive operation the 4 way could be pretty efficient.   But for me, I don’t find that situation very often, and the “normal” QCTP holders are inexpensive and set for the specific tool, just pop it in.   I must have 15 of them loaded with different tools.  And a few empties for what new need arises.


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## T Bredehoft

Winegrower said:


> the inexpensive wedge type QCTP ... capability and ease of use, coupled with the low cost of more holders



I concur  with    Winegrower, above. However, funds for the Aloris type tool holder and tools have eluded me. I was trained with a Lantern Post, back, before the dark ages, then as progress overtook my employer, the entire tool room  built for themselves an indexiable four square tool holder.  We each had one, and spacers to make them fit the lathes in the toolroom. When retirement allowed me my own machines, I  build the four square I remembered from my apprenticeship.


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## TakeDeadAim

mickri said:


> Found a you tube video where a guy made one of these for his mini lathe.
> 
> 
> 
> 
> 
> 
> And I found a you tube video that showed how the indexing on a 4 way tool post holder worked.  So I have figured out how to make one of these tool post holders indexable.  I have some of the steel that I need and will order the rest.



Was it just me or was watching the video of that guy making the toolpost scary?  Wanted to look away and not see the thing fly out of his wooden and home cast aluminum lathe.


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## jdedmon91

T Bredehoft said:


> I concur with Winegrower, above. However, funds for the Aloris type tool holder and tools have eluded me. I was trained with a Lantern Post, back, before the dark ages, then as progress overtook my employer, the entire tool room built for themselves an indexiable four square tool holder. We each had one, and spacers to make them fit the lathes in the toolroom. When retirement allowed me my own machines, I build the four square I remembered from my apprenticeship.



That sounds like a concept. In my younger days that is what was on the lathes. The only 4 way was on Turret lathes. 


Sent from my iPhone using Tapatalk


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## mickri

I have finished cutting the tool holders out of a 1.25x2.25x18 hunk of 1018 and have finished off the rough ends left from the the saw cuts on my mill/drill.  I cut these with my sawsall.  Not pretty but it got the job done.  Took awhile.   I ended up with seven 1.25H x 2.25W x 2.50L pieces.

Of these 7 pieces my plan is to make four to hold my atlas/craftsman tool holders which are 3/8x3/4 or 3/8x13/16.  I will make these 3/8x13/16.  These holders could also hold 1/4 to 3/8 HSS tooling.  I am thinking of making one holder to hold 1/2 HSS.  Or make this holder to hold a drilling attachment like I recently saw on another thread.  The final two pieces I plan to make to hold boring bars.  My largest boring bar is 5/8 diameter and will make one holder to hold this boring bar.  I would also use this holder with my 1/2 boring bar.  The final holder I would make to hold 3/8 and smaller boring bars.  I have a bunch of these.

All of these holder will have the same hole layout except for the holder for the 5/8 boring bar.  My question is how thick should the wall be between the end of the holder and the boring bar and between the boring bar and the center post?  I can make these walls up to 1/8 thick.


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## mickri

Here is a top view sketch of the holder for the 5/8 boring bar holder with 1/8" walls as in my previous post.


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## mickri

This morning before having to go to town on errands I was able to get all of the holes marked.  I used CAD aka cardboard aided design to make a template to mark the holes.  This form of CAD has been around long before the advent of computers.  Tomorrow I hope to start drilling holes.


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## mickri

I finally got the first holder done.  I made a holder for my 5/8" and 1/2" boring bars.   I made this one first because I needed a holder for these boring bars and it will get used to make the rest of the holders.

It's not pretty.  In fact it's down right ugly.  Twice when making light cuts on the mill, one a .005 & the other just a skim, the end mill somehow caught the edge of the holder and walked it partially out of the vice.  I have no clue as to why this happened.

Super easy to set on center.  It does take a good deal of torque to tighten the clamp nut.  Learned a lot making this one.  The others should be easier and quicker to make.


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## mickri

Started on the holder for the 3/8 and smaller boring bars today.  Got the large center hole bored out.  Took me 3 hours to bore a 1 1/4" hole.  The first 3/4" goes fast because I am able to use my drills.  Wish I had a 1" drill.  After that it is .020 per pass to start with and then down to ,010 to .005 to .002 to .001 and finally .0005 passes as I sneak up on the final size.  And with each decrease in cut I take a couple of spring cuts.  And then there is the measuring.  I need lots of practice measuring holes.  I am getting better at it.  I can now get consistent measurements within .001 to .0005.  I take 3 measurements and do a mental average.  Tomorrow I will measure bore and compare it to the size of the post.  That was today's afternoon project.  My morning was spent long boarding the body of my 66 MG Midget.   Not a very fun project but it has to get done.


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## BaronJ

Hi Guys,

I can't find the original references to the "Norman Tool Holder"  But the original didn't use a bolt to clamp the holder to the post.  That drawing in the PDF is modified to use a clamp bolt.

The original design used a split pinch clamp that actually closed on the post directly.  Yes it had a screw through it which pulled the two half's of the clamp together.  This also allowed a further modification of a handle to clamp the holder without any tools.


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## mickri

Got another holder done.   This one is for my small boring bars.  This holder came out better than the first one.  The first one is on the top and the second is on the bottom in the picture.





Two down.  Five to go.  It takes me forever to make one.  The next five will all be the same.  Hopefully that will make it quicker to make them.

  I used the first holder to make this one.  Amazing difference in rigidity compared to using a lantern tool post to bore the 1 1/4" center hole.


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## BaronJ

Hi Mick,

Looking good.  Curious as to why you used two screws for hight adjustment.


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## mickri

I was concerned that the holder may rock on the post and the first holder that I made does rock a little before it is tightened to the post.  So I put in two screws.  Maybe overkill.  Once tightened it is rock solid with no movement whatsoever.


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## BaronJ

Hi Mick,

That is one of the reasons that the original design used a split pinch clamp.  The pdf article modified the design, presumably to make it easier to make, or avoid copyright.

I used to have a scan of the original drawing on one of my HDD but I'm stumped to find it now.

I have a new drawing which I have done from memory and the pdf converted to metric dimensions.


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## mickri

The slight rock when loose on my first holder is not because of the clamp method.  It is from a slightly oversize hole in the holder.  There is no rock in the second holder.  The second holder is a very, very tight fit on the post.  Might be too tight.  I am not very good at measuring the diameter of a hole.  I tend to measure the hole smaller than it actually is.  Per my likely inaccurate measurement the second holder is .0005 to .001 smaller in diameter than the post.  I can just barely get it on the post.

If I understand your drawing correctly the pinch bolt when pulled to one side clamps against the post preventing the holder from moving.  I wonder if it would work where the hole in the holder is slightly oversize like in the first holder that I made.  I might try making one of my holders like your drawing.  I would bore hole for the pinch bolt first and with the bolt in it's hole then bore the large hole for the post.   Interesting.


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## T Bredehoft

Sometimes pinch bolts are cut in two at the top of the arc. thread one end, clearance drill the other and float the assembly in the hole. to tighten, tighten the cap screw through the clearance hole. This will 'expand' the pinch bolt   onto the post.  Hope this makes sense.


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## mickri

My intuition is that by splitting the holder like I have and as I have seen on all the plans that I have looked at online provides a larger clamping area around the entire post when you tighten the clamping bolt.  That's just a guess on my part.


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## BaronJ

Hi Guys,

The pinch clamp is, after drilling tapping size, cut in half so that there is a gap between the two half's. 
But before that the clamp is trapped in its hole, and the hole for the post bored, so that the clamp gets the radius machined into it.
If its done properly, only a fraction of a turn on the clamp bolt will lock the whole thing onto the post.

The hole for the holder should be a smooth sliding fit on the post.  It shouldn't be tight.

Mick:
Splitting the holder distorts the hole and whilst it works, the post is gripped on two edges.
If you blue the post and lightly nip the bolt move the holder slightly you will see this.



> I would bore hole for the pinch bolt first and with the bolt in it's hole then bore the large hole for the post.


Yes that would be how to go about it.

Tom:
Yes you almost have it !  The two half's of the pinch bolt clamp together, there is no expansion.


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## mickri

Almost had a major screw up today.  I was down to the last couple of cuts as I was sneaking up on the correct size of the center hole.  I was moving the crossslide in .001 increments to take off .002 at a time when I inadvertently moved the crossslide .011 equating to taking off .022.  When I saw how deep the cut was I knew something was wrong and stopped the cut.  Luckily I was only in about 1/4."  Found my error and finished the hole getting a good fit for the remaining portion of the hole.  The oversize portion of the hole is about .014 oversize.

What should I do about the portion that is oversize?  One thought is to put some JB Weld in the oversize portion and then machine it to fit.  I don't know if the JB Weld would stick long term.  I could also use my welder to lay some beads in this area and then machine the beads to the correct fit.  Or I could do nothing.


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## BaronJ

Hi Mick,

1/4" (6 mm)  I would do nothing !  It isn't going to make any real difference, 14 thou naw...

I try to avoid sneaking up on a size if I can.  Too easy to overshoot as you have found out.

Anyway does this drawing help ?


Note that this split clamp pin diameter is not set in stone.  The end on drawing shows a diameter of 14 mm, only because I happen to have some drill rod that size.  Also the bore is drilled tapping size for M6, but I've shown it as a 6 mm hole.


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## mickri

Thanks Baron,  The drawings definitely help.  I am going to make at least one of the holders per your drawing. 

I have to sneak up on a hole to get the correct size.  I tend to measure holes slightly under their actual size.  If I went by my measurements the holes that I bore would all be oversize.  At least for now.  Maybe someday I will be able to measure a hole to it's actual size.  Or get to a point where my measurements are consistently under size by the same amount.


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## BaronJ

Hi Mick,

Are you boring with the lathe or the mill ?
How are you measuring the bore ?


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## mickri

I am doing the boring on my lathe.  Don't have a boring head for my mill/drill.  I use a telescoping gage and a micrometer to measure the ID of the hole that I am boring.  I am getting better at it.  I now get consistent measurements.  My measurements are smaller than the actual ID.  How do I know this?  As stated in a previous post my measurement of the ID of the hole is smaller than my measurement of the OD of the post yet the holder fits on the post.  So the ID has to be bigger than my measurement.


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## macardoso

Winegrower said:


> I hope everybody considering a four way will check out the inexpensive wedge type QCTP and holders available from many sources, say for example,, CDCO tools.   The capability and ease of use, coupled with the low cost of more holders and styles (boring, knurling, etc.) are hard to beat.



100% on board with this.  I have the CDCO wedge tool post with 7 holders for ~$100.  Nice quality and I can take my tools on and off and they repeat to the same position within a tenth or two.  It makes life so much easier. Plus the height adjustment screw means you don't need to ship.   Some argue that there is a loss in rigidity to a small extent, but I haven't found this to be an issue even when doing heavy machining of alloy steels.


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## homebrewed

I made the Norman style QCTP, too.  The version with the single slit, not the split clamp.  Mine took a lot of "oomph" to tighten on the post as well.  To address that I drilled a 1/8" diameter hole on the other side of the holder,  located halfway between the bore and side of the holder.  Then I cut another slit down to the hole.  The rounded section is used as a stress relief.  This mod made it much easier too secure the holder to the post.

Here's a photo showing my build.  It's installed on a 7x12 mini lathe.  I normally do a lot more facing cuts than threading so the compound is set parallel to the ways.  The post is CRS, the holder is 6061 aluminum.


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## BaronJ

Hi Homebrewed,

Looks nice !  
You have discovered one of the issues with using a screw to clamp in that way.
I think that all the articles showing toolpost designs, using a screw to clamp, in that fashion, have done it that way because drilling a hole and cutting a slit is easier than making a proper spit clamp.


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## BaronJ

mickri said:


> I am doing the boring on my lathe.  Don't have a boring head for my mill/drill.  I use a telescoping gage and a micrometer to measure the ID of the hole that I am boring.  I am getting better at it.  I now get consistent measurements.  My measurements are smaller than the actual ID.  How do I know this?  As stated in a previous post my measurement of the ID of the hole is smaller than my measurement of the OD of the post yet the holder fits on the post.  So the ID has to be bigger than my measurement.



Hi Mick,

Try doing it the old fashioned way with inside calipers and a micrometer.


----------



## homebrewed

Thanks, BaronJ.

I'll have to try a split clamp on the next tool holder I make.  It really isn't much more work than what I did as shown above.  I want to make a boring bar holder anyway....


----------



## mickri

On my first holder for my 1/2 & 5/8 boring bars due to a lack of room I used a 1/4 x 20 bolt as my clamping bolt.  It only takes 1/4 turn to clamp the holder tight to the post.  And it takes a lot of force on that 1/4 turn.  On my next holder for my small boring bars I had more room for a larger 3/8 x 16 bolt.  The force required is a faction of what was needed for the 1/4 x 20 bolt.  Slightly less than a 1/4 turn to clamp the holder to the post.  I now know that a 5/16 x 18 bolt will fit on the large boring bar holder.   If I can figure out a way to fill the existing hole for the 1/4 x 20 bolt I will try to fit a 3/8 x 16 bolt on the large boring bar holder.
Moral of this is to use the largest bolt possible for the clamping bolt.


----------



## homebrewed

mickri said:


> Moral of this is to use the largest bolt possible for the clamping bolt.



I would think the 20TPI threaded bolt has a greater mechanical advantage, so, all else being equal, it should be easier to tighten it down.  Also, because of the finer thread, you would expect to turn it more for a given amount of "squish".  I suspect you are mostly seeing differences between the two big holes you bored.

I used 10-24 bolts for everything on mine -- the closer and the 3 for holding the cutter in place -- and they work fine for me.  However, my tool holders are made from 6061, not exactly an apples-apples comparison!


----------



## BaronJ

Hi Mick,

This is the way I measure a bore !



Outside spring calipers.  If you buy a Chinese one, make sure that it has rounded ends, like small balls.
I've seen one that actually had tiny balls fastened on the ends of the legs.



This is how you use it.  Here I'm going for 35 mm.



And here is the actual micrometer reading.  Maybe 10 microns over.


----------



## mickri

Today I finished boring the last of the center holes.  Next chore is to mill the slots for the atlas craftsman tool holders.  I will measure the holders again.  From memory they were 13/16 high by 3/8 wide.  I am thinking of making the slot .82 high by .40 wide.  The slot will be 2 1/4 long.  Milling the entire slot would take me a long time.  To make it go quicker I thought of drilling most of the material away and then cleaning up the slot with the mill.  Which way to drill the holes is the quandary.  And what size drill to use.  I think using a 3/8 drill and drilling two holes the length of the slot would be better than drilling a bunch shallow holes.

Suggestions please.


----------



## BaronJ

Hi Mick,

I just clamped it up in the mill vice and ran the cutter across six times taking 2 mm deep cuts.  But yes drill most of the meat out if it makes it easier.

Another picture for you,


Here I am about to take my third or fourth 2 mm cut.  12 mm four flute slot drill.  Chinese HSS 



This is one of my Norman tool post holders.  It goes from free to locked with about 1/4 turn of the cap screw.


----------



## homebrewed

BaronJ said:


> This is one of my Norman tool post holders. It goes from free to locked with about 1/4 turn of the cap screw.



Out of curiosity, how does your tool holder lock to the post?  I don't see a slit cut in the holder, so the locking principle appears to be a little different from most Norman-style tool holders.

BTW I like the nut you made -- it looks pretty nice.

-H


----------



## mickri

Nice job on your tool holders.  My boring bar holders are are a little on the rough side but work well.  Mine also take only a 1/4 turn to go from free to locked.  I have been using the two boring bar holders to bore the center holes on the remaining five holders.  I have decided to complete one holder as a test run.  I will try cutting the slot with just the end mill without drilling out most of the material to see how that works for me.  I can hold all of the last four holders in my vise at one time.




That way I can cut the slot in two of the holders at the same time.  Then do the other two.  I have been using the slowest speed on my mill in previous projects.  For this I think that I will figure out what speed I should be using and see how that works for me.


----------



## BaronJ

Hi Homebrewed,

It uses the original design of the Norman tool holder and is the same as Rolls Royce use in their experimental workshop.
If you scroll up the post you will see the drawings that I posted showing the split clamp.  Posts 48 and 54.

The nut was a scrap of free machining 25 mm AF hex bar.  Drilled and threaded 7/16" BSF.
The shaping was done with a carbide wood router bit.



The only reservation I have is that I only have 1/4" inch shank versions of these.  I would have preferred a 1/2" shank one.
Run at around 800 rpm in the mill and about 600 rpm in the lathe.
This picture was when I did the Norman Tool Holder shaping on the back edges.



Here I am using the router cutter to round off a brass tip on the end of an M6 screw.


----------



## BaronJ

mickri said:


> Nice job on your tool holders.  My boring bar holders are are a little on the rough side but work well.  Mine also take only a 1/4 turn to go from free to locked.  I have been using the two boring bar holders to bore the center holes on the remaining five holders.  I have decided to complete one holder as a test run.  I will try cutting the slot with just the end mill without drilling out most of the material to see how that works for me.  I can hold all of the last four holders in my vise at one time.
> 
> View attachment 276819
> 
> 
> That way I can cut the slot in two of the holders at the same time.  Then do the other two.  I have been using the slowest speed on my mill in previous projects.  For this I think that I will figure out what speed I should be using and see how that works for me.



Thanks for the picture.  Be very careful holding several pieces like that in your vise.  I personally would not do that.  You cannot guarantee that the work pieces have faces flat enough to grip each other.  At best I would only hold two, and even then use some cardboard between the vise faces to ensure that they were both gripped securely.  Also tap them down so that they are sitting flat on the vise bottom.


----------



## mickri

Thanks for the heads up.


----------



## homebrewed

Ok, I got it now.  The main body of the holder is NOT split, it's the pin.  It makes for a very clean look!  I'll have to give it a shot -- slitting the holder is a slow job, at least the way I do it....


----------



## BaronJ

Hi Guys,

I think that most of the articles that I've seen put a slit in the block and squeeze it with a clamping screw, did it that way because it was easy to write an article for publication without putting people off because it was hard to make.  Forty or fifty years ago it would never have been done.

I used to have a copy of the original drawings for the Norman Tool Holder,  in those it was a split clamp as in my drawing.
As I mentioned to Mick, splitting the block means that you only have two points of contact on the post.  Using a split clamp actually has three, but those contact points cover a much larger area and thus greater rigidity.

One other important point that I have just remembered.  When splitting the clamp, make sure to deburr the edges of the cut !  If you don't the burrs will cut into the post and make the movement rough.


----------



## BaronJ

Hi Guys,

Here is another picture,


This is the pin after being split. You can see the burrs on those edges that must be cleaned off.



This is how it looks when in place.  That gap is 2 mm wide.


----------



## Janderso

Well done.


----------



## mickri

Started cutting the first slot in a tool holder.  1/2" four flute end mill and 90 rpm.  I know probably way too slow but then I am a newby.  Depth of cut is 0.010.  My mill/drill doesn't seem to like cuts deeper than that.  Here is my set up.




As I make a cut the table jumps back and forth by the amount of the backlash in the table.  It feels like climb milling.  Is this normal when milling a slot?  Or am I doing something wrong.?


----------



## pacifica

mickri said:


> Started cutting the first slot in a tool holder.  1/2" four flute end mill and 90 rpm.  I know probably way too slow but then I am a newby.  Depth of cut is 0.010.  My mill/drill doesn't seem to like cuts deeper than that.  Here is my set up.
> 
> View attachment 277100
> 
> 
> As I make a cut the table jumps back and forth by the amount of the backlash in the table.  It feels like climb milling.  Is this normal when milling a slot?  Or am I doing something wrong.?


tighten the gibs a little?


----------



## BaronJ

Hi Mick,

As Pacifica says, tighten the gibs, you have too much slap in the table.  90 rpm is way to slow for a 1/2" inch cutter !
Make sure you nip the quill as well, you don't want the cutter to pull the quill or the cutter to pull out of the chuck collet.
As far as depth is concerned 10 thou is barely a scratch.

But since you are learning, try 20 thou (1/2 mm) and see how the machine behaves, increase the rpm's to say 400.  That mill has a substantial round column, so if the table is tightened up you should easily be able to do a 2 mm (80 thou) deep cut, which I can do with mine.

Also its nice to see that you have taken my advice about not ganging up workpieces.

Keep me informed about how you get on.


----------



## mickri

I checked my backlash and it was way out.  Undid the lead screw on one end and slid the table to one end to expose the lead screw nut.  Found that one of the bolts that holds lead screw nut in place was loose.  Tightened everything up and my backlash is back to its usual 0.005.  In process of tramming the vise and then hopefully I can get the tool holder close to where it was.  I don't have to be absolutely exact on the tool holder because I was milling about 20 thousands from my line on one side with lots of room on the other side of the slot.

I'll try the faster speed and deeper cut to see how that works.


----------



## mickri

Tightening up the lead screw nut solved the problem.  The faster speed and .020 cuts worked well.   Baron thanks for the suggestion.  I got the slot cut.  Only have 4 more to go.   I'll start on those tomorrow morning.


----------



## BaronJ

Hi Mick,

Thats good to hear !  But you are going to have to watch that bolt.  If its come loose once it will probably come loose again.
Some of the threads on both the bolts and in the holes leave something to be desired in terms of fit.  That non setting thread lock could be used with advantage.

However do check the gibs, no point in them being too loose if its going to compromise your ability to cut material properly.  Check them at the ends of the table travel, that they don't get too tight there.  The most wear is usually in the middle and that is where the table will be at its loosest.


----------



## mickri

Finished the last of the slots this afternoon.  The first slot took me almost 3 hours to cut.  The last one this afternoon took just under 30 minutes.  I think that I am getting better.  Time will tell.  Have 30 holes to drill and tap and five slits to saw.  The atlas/craftsman tool holders that I have are mostly either 3/4 or 13/16 high with some just a littler higher.  I decided that a slot to fit the highest ones did not leave enough thickness for the set screws to screw into to hold the tool holders.  So I am milling all of my atlas/craftsman tool holders down to 3/4" high.  I am leaving the bottom edge as is and only milling the top edge.  That's all for today.


----------



## BaronJ

Hi Mick,

I'm watching and listening !  You know what they say about practice !


----------



## mickri

I basically destroyed two end mills cutting the slots.  Before cutting the slots I did my usual online research.  There seemed to be two camps.  One was don't use an end mill to cut slots/key ways because you will break the tips off of the end mill.  Especially if using a four fluke end mill.  The other camp's response was nonsense.  No problem cutting slots/key ways with end mills.  I am with the don't do it camp at this point.

As I was cutting the second slot I noticed a line in the side of the slot.  After I finished the slot I took out the end mill and some of the tips were broken off.  I attributed this to the problem that I had had with the lead screw nut being loose and the table moving around.  Chucked up a new end mill and cut the three remaining slots.  I didn't notice any problems during these cuts.  Looked at this end mill when I was done and again some of the tips were broken off.

Did some research on sharpening end mills to see if I could save these two end mills.  Found that without ridiculously expensive machines sharpening an end mill is not possible.  The only advice was to save the damaged end mills for making rough cuts.  Then through them away.

The next time I have to cut a slot/key way I will try the drill most the material away then clean up with an end mill method.  I'll also look into key way cutters. 

On a positive note I finished up one of the holders yesterday afternoon.  Took 3 1/2 hours as I stumbled along.  The rest will go quicker now that I have the process down.  I will post some pictures when I get them all done and cleaned up.


----------



## pacifica

mickri said:


> I basically destroyed two end mills cutting the slots.  Before cutting the slots I did my usual online research.  There seemed to be two camps.  One was don't use an end mill to cut slots/key ways because you will break the tips off of the end mill.  Especially if using a four fluke end mill.  The other camp's response was nonsense.  No problem cutting slots/key ways with end mills.  I am with the don't do it camp at this point.
> 
> As I was cutting the second slot I noticed a line in the side of the slot.  After I finished the slot I took out the end mill and some of the tips were broken off.  I attributed this to the problem that I had had with the lead screw nut being loose and the table moving around.  Chucked up a new end mill and cut the three remaining slots.  I didn't notice any problems during these cuts.  Looked at this end mill when I was done and again some of the tips were broken off.
> 
> Did some research on sharpening end mills to see if I could save these two end mills.  Found that without ridiculously expensive machines sharpening an end mill is not possible.  The only advice was to save the damaged end mills for making rough cuts.  Then through them away.
> 
> The next time I have to cut a slot/key way I will try the drill most the material away then clean up with an end mill method.  I'll also look into key way cutters.
> 
> On a positive note I finished up one of the holders yesterday afternoon.  Took 3 1/2 hours as I stumbled along.  The rest will go quicker now that I have the process down.  I will post some pictures when I get them all done and cleaned up.


You can sharpen the ends, not so easy the helix.


----------



## Dabbler

Mickri, I have a friend that sharpens his 4 flute end mills, by hand at a normal bench grinder.  It is one of the many skills it is possible to learn while progressing in machining.  You won't ever get all 4 flutes cutting that way, but you can reuse a wrecked mill a long time that way.

Second,  If you are messing up your end mills, carbide or HSS, you are doing something wrong.  There are thousands of things to target here.  But even on moderately hard steel (Rc 30 and below), HSS end mills will do the trick if you are careful.  If you buy centre cutting end mills (which you should), in good quality, you can plunge mill your keyway, and then finish mill it after.

For 40 years I have been in the 'it isn't a problem to mill keyways and slots' camp.  It isn't a lie, it just takes skill.

If you are trying to mill a slot in a very hard (Rc45 or higher) or carburized shaft, all bets are off.  All that takes is a file to test, and if it skates, then a far more careful approach is required.

Another factor is your setup.  With a tiny mill like you have it takes MORE skill to do a great job without wrecking tools.  To reduce deflection in your column, take light cuts with a  3/8 end mill - it will result in 1/4 (approx) of deflection force on your column.  You will need to run higher RPMs and take plunge cuts.  Cutting using the X feed with a 1/2" end mill may be part of your problem.

Here's a good video on plunge milling:


----------



## mickri

The material is 1018 steel.  The slot is .400 deep by .750 wide by 2 1/4" long.  I had the speed at 400 rpm and each individual cut was .020 or less following BaronJ's suggestion in a previous post.  I don't know the feed rate but I wasn't pushing it.  Just a steady flow.  I first cut one long slot the width of the end mill down to .400 in multiple passes.  I then widened the slot with conventional milling, no climb milling, to .750.  Each cut was again .020 or less.  I will try to take some pictures of the end mills. 

I had watched a video but don't think that it was Tom's.  I'll watch Tom's video.  The video that I watched I didn't think was really applicable to what I was planning to do.  The material was 1/4" aluminum and was being cut all the way through.  It had you start in the middle by plunging all of the way through then going out to the edge and then going all of the way around.  I was cutting a large, deep key way for all intents and purposes.

Cutting the slot had a feel to it like the end mill was alternating between conventional milling and climb milling.

I am open to any and all suggestions.  I do not like damaging tools.


----------



## Dabbler

On a small mill drill like yours (I owned a slightly larger machine than yours for 17 years - it can do capable work) I would have plunge milled to roughing depth, engaging 1/3 of the 1/2" cutter, cutting slowly with lubricant,  I'd then advance about 1/4 the diameter and keep plunge milling until I had a nearly 1/2" slot.  I'd then plunge mill the rest of it to roughing dimension.  You have to be very careful on exiting the slot that you don't catch the cutter - you just cut with a little less pressure..

After that process I'd take the tops of the waves using conventional milling, taking about .010 cuts.  Then I'd mill the final depth, not touching the sides.  The last operation is to climb mill the last pass(es) taking shallow cuts, .005 with perhaps .333 engagement on each pass until I got the sides to spec.

Plunge milling isn't just for aluminum, or for shallow milling.  I once milled cast iron where the guy needed a flat face in between two bosses.  the contact area on the HSS mill was just under 2".  He had broken 2 mills using full engagement.  I plunge milled the surface using .010 steps, and then climb milled the final surface.  It took a few minutes to do the job.  He had been milling/failing for just under 2 hours.

So plunge milling is fast, uses only the END of the END mill, saving your helix for subsequent sharpenings. It creates far less side pressure on the machine as the only contact area is under the mill, not on the side of the mill.  The downside is that you get impatient, and plunge too hard, the *ping*, a cutter will bite the dust!!!  

It is possible to make a jig to resharpen the end flutes on a 4 flute end mill on your own bench grinder.  There used to be a jig you could buy to do this, similar to a drill sharpening jig.  I haven't needed one, because, well, (he said with some embarrassment, ahem)  I bought 2 of those expensive sharpening machines you mentioned.  What you need is something to hold your cutter to an angle, stop the cutter at an engagement on the grinding wheel, and allow you to advance the cutter for each flute.


----------



## mickri

One thing that I am not is impatient.  I don't care if it takes me all day to do something that somebody else could do in minutes.

I had considered drilling out most of the material in the slot and only using the end mill to clean up the bottom of the slot and the sides.  I decided not to because I was concerned about the end mill catching on the protruding edges left from the drilling.   Especially on the climb side.   I could envision a point on the end mill first hitting an edge in conventional milling and then as it rotated hit another edge in climb milling.  In hindsight I probably should have either drilled or plunge milled out most of the material in the slot.

I have watched Tom's video on plunge milling.  It seems like in most of these videos the machinist is always working with aluminum.  I often wonder if what works in aluminum will also work just a well in steel. 

This is something that will come up over and over.  I plan to make a couple more of the holders.  And when I modify the wood cutting band saw I recently purchased to cut metal I will have to cut a key way in a 5/8" shaft for the reduction pulleys.  I do have a key way cutting.  Have not checked the size.

I will look into the angles to clean up the end mills and give it a try.  My thought process is that if something is already broken I can't make it any worse by trying to fix it.  A lot of times I am successful in my fix.

Thanks for all your suggestions.


----------



## Dabbler

I hope you do well with the sharpening!  

--Plunge milling works even better in steel as it minimizes the pressure on the cutting faces.  Give it a try, It is really a great way to go!
Another way I just thought of:  If you take very shallow cuts, you preserve most of the helix, and can conventionally mill the entire slot.  something like .010 depth.  (just spit ballin')

all the best!


----------



## pstemari

The other point not mentioned above is that slotting at full width is rather hard on endmills in general. Taking two passes with a smaller diameter end mill, so that only one side is engaged at a time, is a much less troublesome approach.

Also, do the plunging with a twist drill, not an end mill. I'd definitely drill at least both ends, and chain drilling down the center of the slot will definitely make things easier.

Sent from my Pixel XL using Tapatalk


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## stupoty

I always find 2 or 3 flute end mills better for full width slotting.

Stu


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## pstemari

2 flute end mills (slot drills in Brit-speak) are definitely better for slotting. Much more room for chip evacuation.

Sent from my Pixel XL using Tapatalk


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## BaronJ

Hi Mick,

I also watched Tom's video and noted that he was climb milling as he was going around the sides of that cutout.  Now its possible he did that deliberately in order to get a good finish, however climb milling is not recommended on a light weight machine with badly adjusted gibs and some backlash.  You will get the effect that you described of rattling back and forth as you were cutting.

I personally have not tried plunging into the work as shown in that video.  But next time I need to remove a large amount of metal I will try it and see if the technique is useful to me.

I also touch up the ends of my milling cutters !  I built John Morans, "Four Facet" drill grinder some time ago and found that with some small adaptations I could use it to sharpen the cutter ends.  I haven't made anything yet to sharpen the flutes, although I have purchased another diamond wheel for this purpose.

I was a little disappointed to hear that you have chipped the corners of a couple of cutters.  Usually this is caused by re-cutting chips caught in the bottom of the slot, as is the line in the side wall of your slot.  If you examine the flute edges carefully, you might find a tiny chip in the flute edge.
It is important to brush the slot clean after each run so re-cutting is greatly reduced.


----------



## mickri

I brushed the slot clean after each pass because I had read about the problems caused by chips getting re-cut.   I use a tooth brush to clean away the chips.  I have one for the lathe and one for the mill/drill.  I find that a tooth brush seems to work well for cleaning away chips.


----------



## martik777

I've been using these 'norman' toolposts for years. It's much quicker if you attach a handle to tighten them. I made a few light duty ones with 1/2" steel and a welded on toolholder, the leftmost one is extended to get close to the spindle. 

Get some of these 6mm carbide roughing end mills for cutting the slots. They are almost indestructible
	

		
			
		

		
	



	

		
			
		

		
	
 and only $5 each. 

https://www.aliexpress.com/item/16m...lgo_pvid=4f821837-2fe6-4737-856a-4566617d09f7


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## Bugleone

This is actually a Norman tool post system and a commercial version used to be made by Myford here in the UK.   There is more info on the 'lathes UK' website and also here;

http://www.toolsandmods.com/lathe/mini-lathe-qctp

I first used this design 40 years ago and I am currently making a set for my new small Warco (Weiss) lathe as the Norman is vastly superior to a 4-way on small lathes where access and room are at a premium.


----------



## martik777

KRF company, in the USA, used to make a clone, the omnipost but went out of business. 

You can view their designs on wayback here: https://web.archive.org/web/20131214074735/http://krfcompany.com/overview.html


----------



## BaronJ

Hi Guys,

I vaguely remember that !  There was something with the threaded disc under the tool block.
It stood out because the tool holder was angled forward and out towards the chuck.


----------



## mickri

Spend the afternoon finishing up the last of the tool holders.  They are not pretty and still need some clean up but they are done.  Lots of sharp edges and corners that I will need to round over.  Learned a lot making these that I don't think I would have learned as quickly if I hadn't made them.   I plan to make 4 or 5 more.



	

		
			
		

		
	
.


----------



## BaronJ

Hi Mick,

Looking very nice all lined up there !

Now you need to make the Knurling tool one 
And the flip up threading tool holder, and...


----------



## mickri

Here is my threading tool holder.  Was this what you were referring to?




A tool holder for my knurling tool is not high on my list.  It will come in the next  batch.  Don't know when I will get to that.  My 1966 Midget has been complaining that I am not spending much time resurrecting her so I can take her for a drive next spring/summer.  After finishing getting the rest of my firewood split and stacked I plan to spend as much time as I can on my midget.


----------



## BaronJ

Hi Mick,

Sorry I didn't recognise the threading tool on the other picture.  But yes that was what I meant.

I like the Midget !    Is it a series A engine ?  A bit of envy on my part.


----------



## mickri

The engine in the Midget was toast when I got it.  It was frozen solid and had various other problems.  The cost to rebuild one is exorbitant and you barely have 50 hp.  I am swapping in a Toyota 3TC and 5 speed from an early 80's Corolla.   It is a pretty easy swap.  Only took a weekend to remove the old engine and get the 3TC in place.  I am keeping the 3TC basically stock and expect to have around 80 hp.  The weak point in a Midget is the rear axle shafts.  They are only good for up to around 100 hp at best.  There is a modification that you can do called growlerizing the axle shafts.  Named after a man down in Australia who spread the modification on the web.  Midget axles almost always break in the same spot.  The outer edge of the spider gears in the differential rest on the splines which causes a stress point on the axle shaft.  The fix is to go one inch in from the end of the shaft and turn the shaft down to the root diameter of the splines for about 4 inches then taper the next 6 inches back to the original diameter.  This eliminates the stress point.  A modified axle is good for up to 125 to 150 hp.  See the drawing below.




I plan to do this mod on my lathe.  Will need a taper attachment which is also on my list to make.  More tooling.  It never ends.


----------



## BaronJ

Hi Mick,

Thank you for that info, I knew there was an issue with the rear axle, but I didn't know what it was.
I also vaguely recall a problem with the series "A" exhaust manifold.

But that isn't going to be a problem with the engine change, and another 30 HP will be welcomed. Certainly better than the 44 HP or was it 48 HP that the "A" engine produced.

In my younger days I helped with the fitting of an over bored 1600 cc BMC power unit in one.  The guy who owned it gave me a ride in it one weekend !  I'll not mention brown stains, he totally terrified me.  Some time after that he swapped it for a Lotus 7 kit car with a three litre Rover V6 engine in it.  No way was I riding in that.


----------



## mickri

Before getting the Midget I thought about a Locost 7 which is a take off of the Lotus 7.  Talk about scary fast.  Some of the Locost guys are putting 400 hp plus engines in a 1200 lb car.  I decided building an entire car from scratch was not what I wanted to do.  The Midget will be more than fast enough for me.


----------



## BaronJ

Good Morning Mick,

That is frightening !  I cant imagine 400 hp in such a lightweight car.  I believe the Rover engine was in the 180/200 hp range.  Great on a track, but for a road car !  No, its too much.


----------



## mickri

I was boring the center hole on my ER32 lathe chuck project using my large boring bar holder.  The tool holder kept coming loose.  I kept tightening the 1/4" clamp bolt and ultimately the bolt sheared off.  This was not unexpected.  I was concerned about this when I chose the 1/4 bolt but didn't think that I had the room for a larger bolt.  I can think of two solutions.  One I could buy a stronger 1/4 bolt.  That would be the easiest solution.  Or two I could try to bore a hole for a 5/16 bolt.  Due to the location of 1/4 bolt hole if I just enlarge that hole I think that it will be too close to the edge of the holder.  So I would need to drill the hole for the 5/16 bolt offset slightly.  I don't think that I could do this with a drill even if I filled the 1/4 hole with a bolt held in place by JB WELD.  Might work.  Could you do this with an end mill plunging it into the holder?

Looking for suggestions.


----------



## BaronJ

Hi Mick,

Yes you could move the hole using a slot drill / end mill,  But you will have to make sure that your setup is sufficiently rigid.  You could, if you are careful open the hole out as you move it to suit a split clamp arrangement as I showed.

But you would then have to bore inside the holder bore, to cut the radius in the pin without damaging the holder bore.  Or you could just cut the radius in the pin, free style.  Not difficult to do !  But takes care and time.


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## Dabbler

a 5/16 bolt is 1.5 times stronger than a 1/4 bolt.  if you went to a grd 8 bolt, and went 5/16 it would help.  3/8 would be more than twice as strong, if there's room.  If they are made with 1/2" steel, you can safely go to 3/8 which will be a lot better.


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## mickri

The the large boring bar holder is the only holder with a 1/4 bolt.  It looks like I have room for a 5/16 bolt if I can offset the hole.  I don't think that a 3/8 bolt will fit.  I will measure it again.  All of the other holders have a 3/8 bolt.  If I can't successfully offset the hole then I will make another holder for the large boring bar.


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## BaronJ

Hi Mick,

Just a thought, I've been back and looked at your pictures,  if you put a saw cut in the holder one on each side of the post hole, say 50% of the material thickness, it just might allow the holder to flex more and give a slightly greater grip area.


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## mickri

I thought about making the saw cut wider when I made the holders.  I also thought about milling more of the material away so that the sides would be thinner and have more flex.  I saw one picture where one side followed the curve of the center hole and looked to be 1/8" to 3/16" wide.  Without a rotary table I didn't know how I could do that other than rough cut most of it away with whatever and then use a grinder to smooth it out.


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## burdickjp

I built a Norman-type setup a few years ago for a 7x10 lathe:
http://bbs.homeshopmachinist.net/th...ve-quick-change-tool-post?p=942116#post942116

When I sold that lathe and bought a bigger one it came with a DRO, so this time around I am making an Alciatore style QCTP: http://bbs.homeshopmachinist.net/th...ve-quick-change-tool-post?p=911132#post911132


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## burdickjp

Something I did on mine was offset the slitting operation so one side has more material than the other.


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## mickri

I thought about offsetting the slot.  I just went with what everybody else was doing with the slot centered.  I am going to make a holder where the holder follows the curve of the post.


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## mickri

I enlarged the existing hole and threaded it for a 5/16 x 18 bolt.  Picked up a grade 8 5/16 bolt which tightens the holder to the post.  No more slippage. Looks like I got the problem solved.


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## mickri

When I made the base of the tool post I left it flat with nothing fitting into the T slot.  I have had issues with the base and post twisting under heavy cutting loads.  I don't like how tight I have to tighten the base and post to keep it from twisting.  I don't have any stock on hand thick enough that I can use to make a new base.  My thought is to weld a piece of steel to the base and machine it to fit the T slot.  Is this an acceptable solution?


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## BaronJ

Hi Mick,

Based on your picture in post 24, I thought that you had made it so that it fitted into the "T" slot.  A temporary fix might be to put a piece of paper under the plate and tighten down on that.  The post on mine is 38 mm in diameter and locks solid.

With regard to indexing, I've never used it or needed to.  If I want to square the holder or the tool bit, I just use the chuck face.


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## GrayTech

Alignment pins would work great for what you want to do, and they don't need to be permanent. 

Sent from my H3123 using Tapatalk


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## mickri

Finally got to fixing the base and the post from moving.  I did two things.  First I welded the post to the base.  To do this I mounted everything on the compound and tacked the post to the base in four places roughly equally spaced around the post.  The base wasn't really thick enough to mill off a portion leaving a protrusion to fit the slot in the compound.  So the next thing that I did was to cut a piece of 1/8 steel to precisely fit the slot on the compound.  I then tack welded it to the base with everything mounted on the compound.   Both of the tack welding was a little nerve racking because I was worried about splatter from the welding damaging the lathe.  My welder is a little HF flux core welder.  Not the best but it got the job done.  I did the final welding in one of my vises.

The really tricky part of this fix was turning the post at the base back down to the correct diameter so the tool holders would slide all of the way down the post.  The threading tool holder has to sit on the base to be on centerline for threading.  It was a long reach for a tool to get in there and it had to cut right up to the base.   The area I needed to turn was maybe an eighth inch wide.  I first tried my parting tool held in a lantern.   The blade had to be so far out that it just bounced around when I tried to make a cut.   So I took a piece of 3/8 HSS and ground the end similar to a parting blade.  This worked.  Here is the completed fix.  Did not take pictures of my set up to turn the post.  I can recreate if anyone is interested.




I am sure that some of you will notice that "T" bolt is perpendicular to the locating piece welded to the bottom of the base.  I just did not straighten it to the correct orientation when I took the picture.  Oh well.  The "T" bolt is made out of a carriage bolt.  I milled the flats on the bolt to be truly flat and not angled.  The sides of the head were also milled to fit as was the top of the head.




This afternoon I used the tool post holder to finish cutting the threads on my ER32 chuck.  No more movement and only took a reasonable amount of tightening to hold everything in place.


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## Larry42

I'm with Winegrower on his post. QC tool holders are relatively cheap so you can buy lots of them and have true "Quick change" capability. Having to readjust tool ht. for every tool change seems like a huge waste of time. Make yourself a height gage for when it is required.


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## Dabbler

Larry I need to clear up a misunderstanding, again, if I may.  My 4-way carbide tooling are NEVER adjusted for height.
 - They have been milled and ground so they are ALWAYS at the correct height.

In fact, I'm fiddling my QCTP holders from time to time, but never my 4 way.


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## mickri

One of the next batch of tool holders that I plan to make is going to be a 3 way for the 3 tool bits that I use most often.  Can't do a 4 way because I need one side for the clamping screw.  I will do like Dabbler did and grind the bits to all be the exact same height.


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## Larry42

Dabbler, I've got a few HSS tools with a top rake. Seems like those would need shimming after a sharpening. My parting tool holder mounts the blade at an angle, so every time I change the cutting depth, the tool holder needs adjusting up/down. I've never had the pleasure of using a 4 way tool post so I don't have a clue how such things are compensated for.


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## Dabbler

ah.  So here's what I do:  I keep 4 way, lantern, and QCTP tool posts for my lathes.  I love the QCTP in many contexts, but for carbide insert tooling, I go to my 4 way a lot.

- now for HSS I usually use the lantern - for all my 1/4 by 1/4 tooling.  I recently have gotten a bunch of 1/2 X 1/2 hss tools, and I'm going to start by using them in the QCTP.  

That being said, my tool height is .609 from the bottom of my 4 way so I'm making a permanent 'sled'  Kinda of a shim, but with sides for my 4 way that will bring the tip to the centre height.  For HSS regrinds, the QCTP is prpbably the way to go if you don't have lantern tooling.


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## Larry42

1/4" tools seem too small for my tool holders. Mostly use 3/8"and some 1/2 & 5/8 where I'm likely to be hanging out or form cutting.


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## pstemari

¼" sq tools are perfect for the tool post on a Taig 

With bigger lathes, they are best in the toolholders typically used with a lantern toolpost, although if you're set up for ½" tooling, you can always use a second ¼" blank tool bit as a shim.

I bought enough QCTP tool holders from the start that I really don't have any reason to use the 4-way. In fact, I have never cleaned the factory anti-corrosion grease off of it—it just lives in a box on the floor behind the lathe.

Sent from my Pixel XL using Tapatalk


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## dgehricke

here are my tool holders, about 25 years ago these holders were sold as a kit for I believe $45.00 you got the drawings and some metal to make a certain series i.e 900 this one is perfect for 9-12 lathe I have an Atlas 10F I love these things. make your own and learn


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## martik777

Those were made by KRF company called the  omnipost out of business now:
https://web.archive.org/web/20131214074735/http://krfcompany.com/overview.html


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## dgehricke

Thats exactly who sold me the kit I had enough stock to make 3 holders and ALL the drawings I browse eBay for bargains and I found 3 for sale about 5-6 years ago it was the ¾ boring bar one and the post and the washer for $30.00  another time I bough only the 12 degree left hand holder for $15.00 all the others I made. I didn't know that KRF was out of business so I guess the drawings I have I can now share ??
dgehricke


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## Dabbler

It looks like a very nice tool post!


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## dgehricke

I'm very happy with this set up and its cheaper then the Chinese junk and the tool bit size is ⅜ I have loads of blanks and a lot of pre ground bits
this is a win win tool post for me.
dgehricke


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## martik777

dgehricke said:


> Thats exactly who sold me the kit I had enough stock to make 3 holders and ALL the drawings I browse eBay for bargains and I found 3 for sale about 5-6 years ago it was the ¾ boring bar one and the post and the washer for $30.00  another time I bough only the 12 degree left hand holder for $15.00 all the others I made. I didn't know that KRF was out of business so I guess the drawings I have I can now share ??
> dgehricke



Yes, I would think sharing them would be no problem.

Do you use the indexing plate? I stopped using mine because I frequently needed a position between the index indents.  I now have one index indent for parting off only. Add a handle like in post #97 to avoid using a wrench.  For lighter cuts, you can make these with thinner material (3/8") and weld on a piece to hold the toolbit, also pictured in post #97


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## dgehricke

I do use the indexing washer if I have an alignment problem I loosen the bolt that secures the post make adjustments and I'm off to the races.
Who can I check with about the drawings I sure don't need legal problems and this site don't need problems either.
Who's uncharge of the downloads I'll send the drawings to that person that way there's no problem later or any finger pointing.
dgehricke


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## martik777

My post was slipping during knurling ops so I added a removable 1/2" pin. I still need to be able to rotate it to align the parting tool to the index indent.


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## dgehricke

Good idea my post is hardened and drilling a hole with out carbide drills would assure that I will screw it up.Best left undone.
dgehricke


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## martik777

Hardening may only be a few thou deep, break thru that with carbide drill or end mill and you should be able to drill the rest with HSS or just try with HSS, it may not be too hard.  You could also make another post.


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## AmericanMachinist

I am planning to make tool holders of this style.   Thanks @mickri  for posting the full PDF scans of the article in the original post.  

*What tool would you use *to cut the 45* bevel shown on the rear-left of the tool holder bodies (top-left image)?   I pictured using an end mill with a 45" cut and a flat bottom cut, sort of an inverse-dovetail cutter.  But I'm not seeing these on McMaster.

I'm also considering flipping the design when applied to boring bar-type holders, so that the cutout, the height-adjusting screw, and the body-tightening bolt are all on the right-side of the tool post rather than the left.  This in my theory provides the benefit of allowing me to use my right hand to tighten and loosen the body-tightening bolt.  Because I plan to add indexing detents to base, I don't foresee a complex 2-handed operation to install the tool holder. 

Am I missing anything in making that change?  

Thanks!


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## mickri

You can make these anyway that you want to.  Doesn't seem to matter.   I have done several different styles.  I have found that you don't need the 45* angled cutout.   I made the cut outs with an end mill.  Nothing special.  First milled out the flat portion.  Then clamped the holder in the vise at a 45* angle and milled the angled portion.   Just leaving it squared off seems to tighten just as easy as with the cutouts.   I will not make the cut out in any future holders that I make. Takes 1/4 turn with the wrench to go from loose to tight.

5/16 bolts are the smallest you can use.  I tried 1/4 bolts and twisted the head off trying to get it tight.  3/8 bolts work the best.  If you do make the cut out you have to be very careful with the position of bolt.  You have to have enough clearance for a wrench to fit on the bolt. 

I have found that 1/4 set screws are sufficient to hold the tool bits.  I used 5/16 set screws to start with.  The most recent ones that I made have all been 1/4 set screws. 

After Mikey schooled me on the forces and geometry of parting I made a special holder for parting.  It sits on the base.  No height adjustment screw.  I used to be parting challenged.  With my new parting holder no more problems with parting.  Winky's Workshop has good videos on making a parting tool holder.  I followed his design.

I found that you need a nut on the height adjustment screw to lock it in place.  Otherwise it will move with vibration and handling so you loose your height and have to reset the height.  And you have to be careful with the position of the height adjustment screw so that you can get a wrench on the nut to tighten it.  You also don't need a 1/4 screw.  There is no load on the screw.  A 10/24 screw will work just fine. 

I have made 12 holders so far and plan to make a couple more.  Including a knurling tool based on Mikey's design.


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## macardoso

AmericanMachinist said:


> I am planning to make tool holders of this style.   Thanks @mickri  for posting the full PDF scans of the article in the original post.
> 
> *What tool would you use *to cut the 45* bevel shown on the rear-left of the tool holder bodies (top-left image)?   I pictured using an end mill with a 45" cut and a flat bottom cut, sort of an inverse-dovetail cutter.  But I'm not seeing these on McMaster.
> 
> I'm also considering flipping the design when applied to boring bar-type holders, so that the cutout, the height-adjusting screw, and the body-tightening bolt are all on the right-side of the tool post rather than the left.  This in my theory provides the benefit of allowing me to use my right hand to tighten and loosen the body-tightening bolt.  Because I plan to add indexing detents to base, I don't foresee a complex 2-handed operation to install the tool holder.
> 
> Am I missing anything in making that change?
> 
> Thanks!
> 
> 
> 
> View attachment 352932



Couple of ways to approach that bevel. If it were me, I'd save it for last, tip the part in the mill vise on edge at a 45 degree and use a normal endmill to cut it. You could also use a swivel vise.

There are also chamfer cutting endmills. One type is called a drill mill and is a normal endmill with a 90 degree point on the front. The other kind is more for doing small chamfers, but you can make it work if you take your time.



			https://www.mscdirect.com/browse/tnpla/32905226?cid=ppc-google-New+-+Milling+-+PLA_stKWB4GsG___164124449414_c_S&mkwid=stKWB4GsG%7cdc&pcrid=164124449414&rd=k&product_id=32905226&pgrid=35979545006&ptaid=aud-839274149441:pla-467315077379&gclid=EAIaIQobChMI2_WN3-C-7gIVHey1Ch1FQQaWEAQYASABEgJbkPD_BwE
		






__





						Chamfer Cutters-Pointed & Flat End
					






					www.harveytool.com


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## AmericanMachinist

Thanks! are yours roughly 2x2" 1018?  Or similar?   1-1/4" post it looks like?  I need to order materials one evening soon and want to make sure I size mine so they lock with a quarter turn as you mentioned yours do. 

Thanks


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## mickri

The first batch that I made was out of 2 1/4 x 1 1/4 1018 bar stock.  I brought it online.  The shipping cost as much as the steel.  The second batch that I made was out of 2 x 1 1/4 1018 bar stock that I got from local machine shop.  Still have some left to make more tool holders.  I have been in there several times since and no matter what I buy I pay $30.  Works out to be under $.50 per pound.  Most of my holders are 2.5 L x 1.25 H x either 2 or 2.25 W.  The center hole is 1.25 ID.  The only critical dimension is the holders need to be a very close fit on the post.  Within .001 to .002.

Have you read my thread where I summarize making my tool post and the holders?  Norman style QCTP | The Hobby-Machinist (hobby-machinist.com)  I go through everything that I think you need to know to make a Norman style QCTP.


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## homebrewed

I use lengths of #6-32 all-thread for the height adjuster to get a little more control over the height adjustment.   I smooth the bottom so it doesn't scratch the top slide.  As micri said, the height adjuster doesn't carry any load so you have a lot of choices there.

This style of QCTP accommodates many different approaches.  Hence all the different versions you see out there; and most users seem to be happy with the final product.  I like mine, not least because it's relatively easy to make whatever you need.

Mine is mounted on a relatively small lathe that can't take really deep cuts anyway so I make my toolholders out of 6061 aluminum rather than steel.  Even the parting tool holder works just fine for me.


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## martik777

Add a handle so you don't have to look for a wrench every time you tighten. You can easily just weld a piece of steel bar to the head of the bolt also.


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## mickri

I thought about making handles but decided not to because I would need a handle for every tool holder.  I have been thinking about going to square headed bolts with the head the same size as the wrench for my lathe.  I will probably try one to see how I like it before converting all of my tool holders over to square headed bolts.


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