# 1127 solid tool post mount



## ttabbal (Oct 9, 2018)

Inspired by this thread, https://www.hobby-machinist.com/threads/solid-tool-post-mount.67428/...

I ended up changing things around a bit for material availability. The base is made from 7075 aluminum, with a piece of ground steel plate on top.

The stud is threaded to match the original M10x1.5 so I can reuse my top speed handle. I went with 3/8-24 for mounting to the top plate as imperial threads are easier on this lathe and I have a nice tap for that size. I milled a couple of flats to make it easier to tighten/loosen.

I need to get some shorter bolts for mounting to the t-slots.


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## mikey (Oct 9, 2018)

Looks nice and solid - good job!  

Does it work well?


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## ttabbal (Oct 9, 2018)

I should be able to find out tomorrow. I can't bolt it down yet.  

Or I could grind ~3/4" off the other 3 bolts, but I'm not feeling that tonight.


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## MSD0 (Oct 9, 2018)

Looks good.


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## ttabbal (Oct 10, 2018)

Wow. I'm liking this setup! I did a little diameter reduction increasing DOC keeping feed the same, though I did increase speed for the last cut...






Nice feeling finish for every cut. The last one was 0.250" DOC leaving just over 0.030" on the stock. Zero chatter. That's a 3/4" 12L14 bar. Granted, it's 12L14, but that's over 2x the cut I used to get a little chatter on and I could do more, but I ran out of stock. 

One issue, the handle for the top nut ended up clocked toward the headstock. It's not an issue at the moment, but I suspect the regular chucks will disagree with it being there. I'll have to set it up for a new hole.

Correction, 0.250 diameter reduction. 0.125 DOC. Oops.


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## mikey (Oct 10, 2018)

Nice cut. Is the OD on that 0.030" remnant consistent from end to end? If so, that is a really nice cut. Bet your parting off will be better, too.

A simple washer under the top nut will fix the clocking issue. Just adjust the thickness to produce the positioning you need.


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## MSD0 (Oct 10, 2018)

ttabbal said:


> Wow. I'm liking this setup! I did a little diameter reduction increasing DOC keeping feed the same, though I did increase speed for the last cut...
> 
> View attachment 277307
> 
> ...


The solid tool post made a big difference on my PM1127 as well, especially when parting off. I’ve also been able to set up all of the tool offsets in my DRO since the position of the tool post is fixed.


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## ttabbal (Oct 10, 2018)

You know, I hadn't thought to test the remnant. I got out the mic and I'm reading 2 thou larger at the tip. The rest is under a thou difference. Not bad considering I wasn't really trying to do it. I haven't tried parting on it, but I will soon. I also have the parts to try building a camjack knurler so that will get tested. I've never bothered to use the bump knurler. 

A washer. I really should have thought of that.  How would one turn it for thickness though? Super glue mandrel clickspring style? I've never tried to hold something like that. I guess I could do it in 2 operations, hold from the center then switch.. Of course, the ones I have might just be the right thickness to start with.


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## BaronJ (Oct 10, 2018)

Try a wax chuck, 





That is a piece of 1/8" brass plate.  It is secured by means of shellac used as an adhesive.  The last picture shows that it is just a piece of aluminum turned so it can be held square in the chuck jaws.


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## MSD0 (Oct 10, 2018)

I’ve used brass 5C “emergency collets” to hold onto thin parts. Not sure if there’s something similar for ER collets.


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## MSD0 (Oct 10, 2018)

After looking at your first pic, I was wondering where you mounted the x-axis scale for the DRO. Are you using magnetic scales?


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## mikey (Oct 10, 2018)

ttabbal said:


> A washer. I really should have thought of that.  How would one turn it for thickness though? Of course, the ones I have might just be the right thickness to start with.



Face it, drill it, part it. The part should be accurate enough for a washer. If not, put it in the chuck and face it.


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## ttabbal (Oct 10, 2018)

MSD0 said:


> After looking at your first pic, I was wondering where you mounted the x-axis scale for the DRO. Are you using magnetic scales?



It's a glass scale. I like the idea of the mag scales, but not the price. 

It's hanging off the back of the carriage. You can see one of the support bars in the second pic. I can take some more pics of it, but it's based on the idea from this video. 



 I had considered doing that, but kept waffling about it. The video convinced me to try it and I've been happy with the results. I've tested it against micrometer measurements and it's very accurate.


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## ttabbal (Oct 10, 2018)

mikey said:


> Face it, drill it, part it. The part should be accurate enough for a washer. If not, put it in the chuck and face it.



Wow.. I'm good at overcomplicating things.  I was thinking of trying to chuck up a pre-made washer and face it down. Your way is probably easier and I can make whatever diameter I want.


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## jbolt (Oct 10, 2018)

The washer does not need to be super thin.  Just make it .1" + oversize. Turn and bore a shaft to the OD/ID and part off to size. You can calculate the needed thickness by the pitch of the thread. Divide the pitch length by 360 and then times by the approximate angle needed to clock the nut to the correct position.


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## epanzella (Oct 10, 2018)

That block looks too tall. Seems like larger diameter pieces will interfere with it on partoffs and groove cutting. My block is substantially shorter than that and I still had to cut a corner off for chuck clearance.


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## ttabbal (Oct 10, 2018)

The height matches the compound, width is close. It is a possibility that it might end up causing issues though. It's something I'll have to watch for.


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## MSD0 (Oct 10, 2018)

ttabbal said:


> The height matches the compound, width is close. It is a possibility that it might end up causing issues though. It's something I'll have to watch for.


I think I made mine slightly shorter (2.25”) than the compound. I had a couple of tools that were almost on center when the holder was bottomed out and wanted a little extra room for adjustment.


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## ttabbal (Oct 11, 2018)

MSD0 said:


> I think I made mine slightly shorter (2.25”) than the compound. I had a couple of tools that were almost on center when the holder was bottomed out and wanted a little extra room for adjustment.



I have a couple of 1/2" tools that are a bit close that way. I went this way figuring it's a lot easier to cut more off than to put the chips back. 

There are a number of considerations that I didn't consider until I started test fitting this thing. It's been a very interesting project and I learned a few new things about my lathe.

Thanks for posting your drawing! I got a number of dimensions from it to help line things up.


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## ttabbal (Oct 11, 2018)

Got the handle clocked properly. The formula above to calculate the thickness came in handy. 

Parting is MUCH improved! I was using aluminum and found that I got excellent results just using the power feed. Nice finish as well.


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## ttabbal (Oct 11, 2018)

mikey said:


> Face it, drill it, part it. The part should be accurate enough for a washer. If not, put it in the chuck and face it.




It's that last bit that confuses me. How do you hold that in the chuck and face it without hitting the chuck? The wax chuck seems like a reasonable option. I actually tried the super glue thing, takes too long to set. The shellac might be better, but it has a shelf life from what I'm reading. Guess I could buy the dry stuff and mix as needed. I ended up just parting off another one, but it made me think that I might want to do something like this in the future and I should probably figure out how.


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## jbolt (Oct 11, 2018)

I will throw out a few more ways to turn thin spacers/washers.

1. If your 3-jaw chuck has two-piece jaws you can use soft jaws.

2. Double sided "flat back paper" tape can be used similar to the wax chuck method.  This is the best double sided tape I have found for work holding when used sensibly. https://www.amazon.com/gp/product/B01B8HLRVY/ref=oh_aui_search_detailpage?ie=UTF8&th=1

3. If you have a large enough ER collet, make a straight wall machinable collet from aluminum rod to fit in the ER collet. It should be about an inch longer than the depth of the collet. Turn a pocket on the face of the aluminum rod the OD of the washer. Drill a hole through the rod so the soft collet can spring. Use a band saw/hacksaw to make an X cut down the rod to within 1/4-1/2" of the end of the rod. 

Half the fun of machining is figuring out how to hold/make parts.


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## ttabbal (Oct 11, 2018)

Thanks @jbolt! Good tips. I don't have 2-piece jaws, something to look for when I'm buying a new chuck at some point though. I did order some of the tape, and will try making a DIY collet. That sounds like a good skill to have. The part I was making this time was 25mm, so about the same as the largest collet I have (1"). But one could drop the OD on the section to go into the ER collet and use the larger area to make the pocket, right? Then when the ER collet clamps, the force would compress the larger section as well. I imagine there is a limit to the sizes this would work for... 

I agree, figuring out how to hold/make parts is interesting. I have no "real" training, so I have to figure things out from reading and videos. And asking the fine folks around here.


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## mikey (Oct 11, 2018)

ttabbal said:


> It's that last bit that confuses me. How do you hold that in the chuck and face it without hitting the chuck?



Okay, you can make the washer from whatever material you want in whatever diameter and thickness you need. I suggest you determine how thick a washer you need to clock the handle to whatever position you desire. Easiest way is to turn the handle to the position you need and then use two feeler gauge stacks of identical thickness on opposite sides of the bolt to measure the space accurately. Loosen and tighten the handle to be sure the thickness is right, then measure the stack. 

Face the stock the washer will be made from, spot drill it and then drill for a close fit through hole down the center. Turn it to the diameter you need and chamfer the edge. Now part it off with the thickness you need and you're done.

Another way is to make it thick enough to allow you to hold it in the jaws of a 3 jaw chuck. Typically, you can hold 0.075 - 0.100" or so. You need to get the washer square in the jaws and you can do that using the "bearing on a stick tool" or with an adjustable work stop from the back (you probably made one of these yet). Tighten the jaws enough to hold it and face it to the thickness you need. I make special thickness washers often enough that I bought a Yuasa magnetic chuck.


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## WyoGreen (Oct 11, 2018)

I came across this video the other day on making thin shims. Quite the interesting video, and I learned lots from it. Joe has several nice learning videos.

Steve


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## BaronJ (Oct 13, 2018)

ttabbal said:


> It's that last bit that confuses me. How do you hold that in the chuck and face it without hitting the chuck? The wax chuck seems like a reasonable option. I actually tried the super glue thing, takes too long to set. The shellac might be better, but it has a shelf life from what I'm reading. Guess I could buy the dry stuff and mix as needed. I ended up just parting off another one, but it made me think that I might want to do something like this in the future and I should probably figure out how.



Hi, With the wax chuck the shellac is heated and melted onto the chuck face to hold the work piece.  You will need to heat both the chuck and the work, then press the two parts together whilst they cool.  I just stand the chuck across the vise jaws and put a 1 Kg weight on top and let everything cool down.

One caveat, facing creates a certain amount of heat, if it gets too hot the shellac will start to melt and the work will give way !  DAMHIKT


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