# Solid Tool Post Riser for my 13"x40" lathe



## ChrisAttebery (Jun 15, 2020)

I bought an import 13"x40" gear head lathe a couple years ago (https://www.hobby-machinist.com/threads/new-to-me-yangzhou-ty-co632-13x40-gear-head-lathe.65871/). As others have noted the compound on these lathes isn't very rigid so I decided to try making a solid tool post riser. I made some measurements and came up with a design in Fusion 360. I designed it so that there aren't any ledges for chips to get caught between the tool post and holders.

Front:



Back:



Top Down:



I still need to add an L shaped plate to lock the tool post in at 90 degrees.

I wanted to use cast iron or steel for the riser but I couldn't find new stock anywhere nearby and buying a block and having it shipped was going to be about $150. I decided to try looking through the scrap at the local metal dealer. The only block I could find that fit my minimum dimensions was a block of scrap A36 steel 7.25" wide, 2.75" tall and 6.3" long. None of the sides were flat. It was only $15 though, so I don't mind doing a couple hours of machining.

I don't own a metal cutting band saw and the block was too big to fit on my Evolution Rage 2 chop saw. So I loaded it up in my CNC converted G0704 and milled away 48 cubic inches of steel (~13.5 lbs.). I used a 3/8" 4 flute carbide end mill at .630" DOC, .025" WOC, 4000 rpm and 40 IPM. That's roughly .5 cubic inches per minute. Two hours later I had a huge pile of chips (at least by my standards).




Once I got the block down to a reasonable size I thought I'd try facing the ends on my lathe. This is the largest piece I've turned with it. A 25lb block spinning at 300rpm was a bit scary at first, but it was reasonably balanced and the ends cleaned up nicely.



At this point I have a block that's the correct width and the sides are parallel. The top and bottom aren't perfectly flat and the end faces are neither parallel to each other nor perpendicular to the top and bottom. My plan is to face the bottom, the top, and then reface the ends. That should give me a nice square block. Then I can start milling the final shape out.


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## hman (Jun 15, 2020)

Good job ... but I think it's high time you treated yourself to a bandsaw!


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## ChrisAttebery (Jun 16, 2020)

hman said:


> Good job ... but I think it's high time you treated yourself to a bandsaw!



Unfortunately there just isn’t room for one. The chop saw handles 99% of what I need cut.


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## ChrisAttebery (Jun 16, 2020)

Last night I got the top and bottom milled flat and pretty close to parallel to each other. Then I moved the piece over to the lathe and faced the ends so that they are square to the top, bottom, and sides. There are a couple places where the surface isn't smooth, but they will be milled away so I'm not worried about them.

At lunch today I used a 1/8" roundover mill to round off the vertical edges of the block. At this point I think I'm ready to start milling the riser out of the block.


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## ericc (Jun 16, 2020)

Wow.  An amazing tour de force of milling.


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## ChrisAttebery (Jun 16, 2020)

ericc, I don't know if I'd go that far, but it's the biggest project I've taken on. Before this the largest piece of steel I machined could fit into the palm of your hand.


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## ericc (Jun 17, 2020)

Hi Chris.  I would love to hear about your experiences and evaluation of this block after you install it.  I did a similar project for my South Bend 9, and it did not help as much as I thought.  Either the compound is pretty solid or something else is loose.  It did seem to help somewhat.


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## ChrisAttebery (Jun 17, 2020)

Sometimes I can see the tool post flexing on my machine. I've examined the compound and I can see why it's the most likely culprit. The way its connected to the cross slide is pretty weak. There are two 8mm bolts holding it down and the contact surface is pretty small. The tool post is also cantilevered off the end. There's only one way to find out if it makes a difference.


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## Buffalo21 (Jun 17, 2020)

Chris,

Interesting design and concept, when I bought my QCTP, I was told the weak joint is at the compound/carriage, but we do the best we can. It would never work for me, I use the compound on a regular basis and am constantly pivoting the QCTP on my 14 x 40 Jet. Still I’m very interested to see the results.


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## epanzella (Jun 17, 2020)

ChrisAttebery said:


> Sometimes I can see the tool post flexing on my machine. I've examined the compound and I can see why it's the most likely culprit. The way its connected to the cross slide is pretty weak. There are two 8mm bolts holding it down and the contact surface is pretty small. The tool post is also cantilevered off the end. There's only one way to find out if it makes a difference.


It makes a difference. I replaced the compound with a tool block on both my lathes. They got more rigid and finishes were improved. It was a big help with parting.


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## ChrisAttebery (Jun 17, 2020)

Buffalo21 said:


> It would never work for me, I use the compound on a regular basis and am constantly pivoting the QCTP on my 14 x 40 Jet.



I'm planning to add a separate retainer plate that will prevent rotation, but you could always use the block without it and rotate the tool post. I'm planning to leave my compound set up with the QTCP stud in place so that I can pull the tool post off, unscrew the 4 hold down bolts, pull the block off, thread set screws in the holes and then drop the compound back on. It sounds like a lot, but I think I can get it down to a minute or two.


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## epanzella (Jun 17, 2020)

Buffalo21 said:


> Chris,
> 
> Interesting design and concept, when I bought my QCTP, I was told the weak joint is at the compound/carriage, but we do the best we can. It would never work for me, I use the compound on a regular basis and am constantly pivoting the QCTP on my 14 x 40 Jet. Still I’m very interested to see the results.


I use my compound as well. I just swap between the tool block and the compound as the project dictates.  It takes about the same amount of time as swapping chucks.


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## f350ca (Jun 17, 2020)

I made a solid post for my Hardinge HLV, I do notice improved finishes when turning but a big difference parting. With the compound installed I have to be gentle parting, with the solid block it never grabs. Switch back to the compound for threading to get the quick retract mechanism.

Greg


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## epanzella (Jun 18, 2020)

My block is held to the xslide with four 3/8 x 16 capscrews. All the compound mounting features are right under it.  Takes a cupla minutes to swap out. I rotate the QCTP to get angles when using the tool block.


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## ChrisAttebery (Jun 18, 2020)

Yesterday I finally took the plunge and started machining the riser out of the prepped stock. I have all of the shaping done. I used a 3/8" 4 flute carbide end mill to rough machine and then finish the top of the step. Then I used a 1/4" 4 flute carbide ball mill to radius the corner where the step and the riser meet. I used the same ball mill to face the 45 degree sloped section taking roughly 60x  .0125" DOC passes. Finally, I spot drilled all of the holes.




This morning I drilled the five large holes 5/8" deep with a 1/4" HSS drill. I'll finish those on my drill press. Then I started pocketing the holes for the hold down screws with a 1/4" 4 flute carbide end mill. I got the front pair done but realized that I might have interference between the tool holder and the back edge of the riser so I stopped. I'm probably going to have to use a 3/8" end mill so I have more reach to get those back pockets done.

After that I just need to chamfer all of the edges and I'm done with the top on the mill.


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## ChrisAttebery (Jun 18, 2020)

I got the pockets machined and chamfered all of the edges. The block is looking really good. I should have taken a picture before I moved on.

Next, I put the block in my 4 jaw chuck, got it as parallel and centered as I possibly can and then mounted the entire assembly on the lathe. It must weigh about 50-60 pounds. I adjusted chuck until the block was centered and then pulled my parallels out from behind the chuck.

I drilled a small center mark and then mounted my live center. I think I should go back and make a deeper center drill though. 

The plan is to turn .150" off the back leaving a 1.565" diameter x .150" deep journal that will seat into the compound pocket in the cross slide.


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## epanzella (Jun 18, 2020)

This thing is a work of art, it should be in a glass case!


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## ChrisAttebery (Jun 19, 2020)

epanzella said:


> This thing is a work of art, it should be in a glass case!



That you sir. It isn't quite as beautiful in person, but I really try to make things that are not only useful but pleasant to look at.


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## ChrisAttebery (Jun 19, 2020)

Last night I got the back side faced and turned the lug that will fit into the hole in the cross slide. 

This morning I finished drilling all of the holes from the top. Then I turned a tapping guide out of 1.75" diameter aluminum to help keep the threads straight. At that point I attempted to tap the 5/8-11 hole to mount the tool post. I'm running in to a couple issues. First, the biggest tap handle I own is only about 8" long so it's hard to get enough torque on it to actually tap the steel. Second, even with the tapping guide I'm having trouble getting the tap started straight into the hole. I need to think about this for a while. My first instinct is to mount it in the 4 jaw and thread it on the lathe. That's probably the safest route. I'll have to see if I can offset the block in the 4 jaw and still clear the bed. 

I've make a couple mistakes but so far none of them have been insurmountable. Hopefully I can get over this next hurdle.


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## Nogoingback (Jun 19, 2020)

Most of the folks on the forum that have added solid plinths to their lathes report improvements in rigidity, though I suspect
the smaller, lighter machines benefit the most.  I found benefits in greater DOC, less chatter and better parting.  Because
it's smaller than the compound, it's nicer to work around and there's no danger of bumping the handle and changing
tool position.

It looks like you're  doing a great job on yours.  Looking forward to seeing the finished product.


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## ericc (Jun 19, 2020)

After all that work, I'd definitely go for the safe approach.  At least a brand new high quality tap, new appropriate sized wrench and great care.


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## ChrisAttebery (Jun 20, 2020)

I got the block mounted and centered in the 4 jaw this morning. Then I ran into the next snag. I usually tap anything 1/2” and smaller. 
Apparently I don’t own an internal threading tool that will fit into the hole. The smallest one I have will fit into a 3/4” hole.

So, do I buy a bigger tap handle, a solid carbide internal threading tool, or a 3/8” indexable steel tool? I need to think this through.


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## Aukai (Jun 20, 2020)

Have you tried the spring loaded guides. Will had a picture up of it in use but I don't remember what thread. I have also run the tail stock up to the tap handle to square it up(or dead center). As I turn the tap handle, I advance the tail stock arbor to keep a little bit of pressure till it starts.


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## epanzella (Jun 20, 2020)

ChrisAttebery said:


> I got the block mounted and centered in the 4 jaw this morning. Then I ran into the next snag. I usually tap anything 1/2” and smaller.
> Apparently I don’t own an internal threading tool that will fit into the hole. The smallest one I have will fit into a 3/4” hole.
> 
> So, do I buy a bigger tap handle, a solid carbide internal threading tool, or a 3/8” indexable steel tool? I need to think this through.


When I need to thread a hole too small for my bars I just make one to the specs I need from a hunk of O1. Turn the 60degree profile on the lathe then mill  off a little more than half (for clearance).  This gives you a front and back cutting edge. Take off the back cutting edge to get into a smaller hole.  Heat cherry red and dunk in oil. I never temper. You can use round stock but I like square because it makes the zero rake angle easily repeatable.


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## ChrisAttebery (Jun 20, 2020)

I have a couple of the Fisher micro tap guides. I didn’t think it would be strong enough for this tap size.

I wound up using my live center to keep the tap straight. I needed a ton of leverage to cut the threads so I used a pair of Crescent wrenches. One on the tap and one on a chuck jaw. It still took most of my strength to get ‘er done.


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## mattthemuppet2 (Jun 20, 2020)

impressive work, looking forward to hearing what you think once you've installed it and taken it for a test run.

Was the 5/8-11 tap a standard hand tap or a spiral point tap? Another thing to remember is that you can go up a drill size for less thread depth if you have a lot of threads engaged. 50% thread depth would be fine given the length of the bolt you'll be using.


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## ChrisAttebery (Jun 20, 2020)

That's a great idea. I'll have to add some to my next McMaster Carr order.



epanzella said:


> When I need to thread a hole too small for my bars I just make one to the specs I need from a hunk of O1. Turn the 60degree profile on the lathe then mill  off a little more than half (for clearance).  This gives you a front and back cutting edge. Take off the back cutting edge to get into a smaller hole.  Heat cherry red and dunk in oil. I never temper. You can use round stock but I like square because it make the zero rake angle easily repeatable.


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## ChrisAttebery (Jun 20, 2020)

mattthemuppet2 said:


> impressive work, looking forward to hearing what you think once you've installed it and taken it for a test run.
> 
> Was the 5/8-11 tap a standard hand tap or a spiral point tap? Another thing to remember is that you can go up a drill size for less thread depth if you have a lot of threads engaged. 50% thread depth would be fine given the length of the bolt you'll be using.




Thanks Matt.

This was just a Irwin Hansen hand tap from Ace HW. As I was staining to get it to cut I kept thinking that a spiral point tap probably would have been a good purchase. I probably could have gone up one drill size, but I was lucky to find the 17/32" drill as it was. They didn't have a great selection. It should have 12 threads worth of engagement. I hope that will be enough to keep it from slipping.  ;^)


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## Tozguy (Jun 21, 2020)

In retrospect how does the single point cutting option look to you now?


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## epanzella (Jun 21, 2020)

ChrisAttebery said:


> It should have 12 threads worth of engagement. I hope that will be enough to keep it from slipping.  ;^)


Over an inch of engagement with a 5/8 x 11 thread? You'll be able to pick the lathe up off the floor with your whole family sitting on the bed!


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## ChrisAttebery (Jun 21, 2020)

Tozguy said:


> In retrospect how does the single point cutting option look to you now?



Magical!

Actually if I had the tool it wouldn’t have been too bad. Especially with the tap to chase the threads.


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## ChrisAttebery (Jun 21, 2020)

epanzella said:


> Over an inch of engagement with a 5/8 x 11 thread? You'll be able to pick the lathe up off the floor with your whole family sitting on the bed!



I believe in TLAR engineering. That Looks About Right.


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## Buffalo21 (Jun 21, 2020)

I go by the “as long as the thread depth/engagement is more than one bolt diameter, your okay” theory


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## Bamban (Jun 21, 2020)

Nogoingback said:


> Most of the folks on the forum that have added solid plinths to their lathes report improvements in rigidity, though I suspect
> the smaller, lighter machines benefit the most.  I found benefits in greater DOC, less chatter and better parting.  Because
> it's smaller than the compound, it's nicer to work around and there's no danger of bumping the handle and changing
> tool position.
> ...



You are right, my 9x20 works great with the solid mounts. I use the backside QCTP dedicated for parting. To mount the plates I just modified 1/4x20 carriage bolts for t-nuts.


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## mattthemuppet2 (Jun 21, 2020)

ChrisAttebery said:


> This was just a Irwin Hansen hand tap from Ace HW. As I was staining to get it to cut I kept thinking that a spiral point tap probably would have been a good purchase. I probably could have gone up one drill size, but I was lucky to find the 17/32" drill as it was. They didn't have a great selection. It should have 12 threads worth of engagement. I hope that will be enough to keep it from slipping.  ;^)



well, a 5/8-11 tap isn't exactly common use so it's hard to justify big $ for one use, but keep your eye open for deals on Amazon. It's hard to get across how much better machine taps (spiral point and spiral flute) are than big box hand taps.


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## ChrisAttebery (Jun 22, 2020)

The compound mounting bolts on my lathe drop out from the bottom so they will have to stay in place when I use the riser block. Yesterday I drilled two 1/2" holes in the bottom of the block on my CNC mill to clear those bolts. Then I was finally able to put the block in place on the cross slide. I indicated the block parallel with the cross slide and clamped it in place. I had only drilled the mounting holes in the block to 5/16" at this point so  I used a hand drill with a 5/16" drill bit to start drilling the mounting holes into the cross slide. I removed the cross slide and finished drilling the holes on my drill press. I forgot what a pleasure cast iron is to drill. I hand tapped the holes to 3/8-16 and mounted the block. It's a little high so I'll have to face about .012" off the top.


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## brino (Jun 22, 2020)

That looks very solid.

Thanks for bringing us along for the build!
I can't wait for some results....

-brino


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## ChrisAttebery (Jun 24, 2020)

Last night I fly cut the top of riser until it matched the height of the compound. Then I machined an alignment plate out of 3/16" HRS. This morning I blued the alignment plate and installed it. I took some test cuts on a piece of 1" 1018 CRS last night. I did a couple passes at .060" DOC, .006" IPR and 460 RPM and then cut off a couple slices with my carbide insert cut off blade. It's definitely stiffer than before. The cut off tool would chatter in steel. Now it just plows along.


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## ChrisAttebery (Jun 24, 2020)

I weighed the riser last night. It's 15 lbs, 12 oz. So I wound up removing 19lbs of steel from the block.


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## brino (Jun 24, 2020)

ChrisAttebery said:


> It's definitely stiffer than before. The cut off tool would chatter in steel. Now it just plows along.



That sounds like success! 
Congratulations, on a great build.

-brino


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## savarin (Jun 24, 2020)

Lovely work. Just one thing, you said you fly cut the top of the riser so it was the same height as the compound.
If you cut it a bit lower than the original height of the compound then larger tool bits can be used as it will allow the tool holder to sit lower.
Thats what I had to do on my 9x20 to be able to use 1/2" tool bits.


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## ChrisAttebery (Jun 24, 2020)

The tool holders are all adjusted to be at center height on the compound. If the riser and compound are the same height then I can swap between them without having to readjust them every time. The BXA toolpost I have is set up for 5/8" tools but almost all of mine are 1/2".



savarin said:


> Lovely work. Just one thing, you said you fly cut the top of the riser so it was the same height as the compound.
> If you cut it a bit lower than the original height of the compound then larger tool bits can be used as it will allow the tool holder to sit lower.
> Thats what I had to do on my 9x20 to be able to use 1/2" tool bits.


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## savarin (Jun 24, 2020)

Ah, didnt realise you had a BXA, my bad.


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## Nogoingback (Jun 25, 2020)

savarin said:


> Lovely work. Just one thing, you said you fly cut the top of the riser so it was the same height as the compound.
> If you cut it a bit lower than the original height of the compound then larger tool bits can be used as it will allow the tool holder to sit lower.
> Thats what I had to do on my 9x20 to be able to use 1/2" tool bits.




I did the same thing when I made a riser for my 10" Logan.  It's about  .100" lower than the compound, and 
allows the use of 1/2" tools as well.


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