# Solid Tool Post Mount



## MSD0 (Mar 1, 2018)

Decided to replace the compound slide on my PM1127 with a solid tool post mount for an Aloris AXA QCTP. Has virtually eliminated chatter (especially when parting off) and has allowed me to set tool offsets for each tool. I’m planning on using miteebite fixture clamps or something similar to prevent the tool post from rotating  
	

		
			
		

		
	

View attachment 260150
View attachment 260153


----------



## Nogoingback (Mar 1, 2018)

Nice job on the mount.  I made something similar for my lathe recently and the improvement in rigidity was well worth the effort.


----------



## MSD0 (Mar 1, 2018)

Nogoingback said:


> Nice job on the mount.  I made something similar for my lathe recently and the improvement in rigidity was worth the effort.


Thanks


----------



## MSD0 (Mar 1, 2018)

Nogoingback said:


> Nice job on the mount.  I made something similar for my lathe recently and the improvement in rigidity was worth the effort.


Thanks, yeah it’s a big improvement on smaller machines like the 1127.
Edit- I still need to try knurling to see how that goes. With the compound, there was a lot of deflection.


----------



## Uglydog (Mar 1, 2018)

One of the guru machinist (no sarcasm intended) videos recently showed similar.  
So that I understand, please confirm that the miteebite fixture clamps will thread into the two threaded holes on the top of the riser.
I'm excited that you are getting better cuts.

Daryl
MN


----------



## ttabbal (Mar 1, 2018)

Was the thickness chosen for a specific reason? I'm sure thicker is better to a point, I'm just not sure what that point would be.


----------



## MSD0 (Mar 1, 2018)

Uglydog said:


> One of the guru machinist (no sarcasm intended) videos recently showed similar.
> So that I understand, please confirm that the miteebite fixture clamps will thread into the two threaded holes on the top of the riser.
> I'm excited that you are getting better cuts.
> 
> ...


I still need to order the fixture clamps, but I used the offset specified by the manufacturer. If for some reason that doesn’t work, I can always machine a flat on the opposite side of the clamp.


----------



## MSD0 (Mar 1, 2018)

ttabbal said:


> Was the thickness chosen for a specific reason? I'm sure thicker is better to a point, I'm just not sure what that point would be.


The thickness is basically equal to the distance from the cross slide to the top of the compound.


----------



## T Bredehoft (Mar 1, 2018)

I'm pleased to see the T slots in the cross slide, the manufacture recognizes that we like to make our own tooling blocks.


----------



## middle.road (Mar 1, 2018)

MSD0 said:


> Thanks, yeah it’s a big improvement on smaller machines like the 1127.
> Edit- I still need to try knurling to see how that goes. With the compound, there was a lot of deflection.


Use a clamp type knurler. Much better and easier than a 'bumper'.

- EDIT -
RobRenz' video  -=- LINK -=-

Need to think about doing this on mine. Since I need to redo the T-Nuts, maybe do up (4) pcs to hold down the block.


----------



## MSD0 (Mar 1, 2018)

middle.road said:


> Use a clamp type knurler. Much better and easier than a 'bumper'.
> 
> - EDIT -
> RobRenz' video  -=- LINK-=-
> ...


Thanks for the link. I finally figured out how to set tool offsets in my DRO (SINO) and have been numbering all my tool holders. Repeatability has been good so far and it really speeds up jobs that require multiple tools.


----------



## jbolt (Mar 2, 2018)

I use the mitee bite clamps on mine. They work great for fine tuning. My CXA has a hole in the bottom for a dowel pin which I also use.


----------



## MSD0 (Mar 2, 2018)

jbolt said:


> I use the mitee bite clamps on mine. They work great for fine tuning. My CXA has a hole in the bottom for a dowel pin which I also use.


Good to hear. I wanted something that was adjustable and also removable in case I needed to rotate the tool post.


----------



## davidpbest (Mar 2, 2018)

middle.road said:


> Use a clamp type knurler. Much better and easier than a 'bumper'.
> 
> - EDIT -
> RobRenz' video  -=- LINK-=-
> ...


You'll partially defeat the purpose of improving rigidity if you use t-nuts.   I tried that approach first, and measurements were not gratifying.   Here is what I ended up doing:

https://www.flickr.com/photos/davidpbest/albums/72157684102384825


----------



## ddickey (Mar 2, 2018)

jbolt said:


> I use the mitee bite clamps on mine. They work great for fine tuning. My CXA has a hole in the bottom for a dowel pin which I also use.


One or two dowel pins?


----------



## wrmiller (Mar 2, 2018)

My 1340GT is the first lathe I have owned that I don't feel the need for a solid tool post. But then I don't push my machines like some folks do. And I use a clamp-type knurler. 

That and I'm always using the compound so removing it would be really silly in my case.


----------



## jbolt (Mar 2, 2018)

ddickey said:


> One or two dowel pins?


Mine only has one dowel pin.


----------



## jbolt (Mar 2, 2018)

wrmiller said:


> My 1340GT is the first lathe I have owned that I don't feel the need for a solid tool post. But then I don't push my machines like some folks do. And I use a clamp-type knurler.
> 
> That and I'm always using the compound so removing it would be really silly in my case.



I agree it's not for everyone but it does make a difference. I recently put my compound back on to do some short tapers. Out of laziness I left it on and began working on some shafts. The difference in rigidity was so apparent I stopped and put the solid riser back on. I think of it as another arrow in the quiver. Not much different than swapping out a chuck.


----------



## wrmiller (Mar 2, 2018)

The design of your compound differs slightly from that on mine, but I don't know if that actually makes a difference.

It could also be that I'm not working on shafts.


----------



## MSD0 (Mar 2, 2018)

wrmiller said:


> My 1340GT is the first lathe I have owned that I don't feel the need for a solid tool post. But then I don't push my machines like some folks do. And I use a clamp-type knurler.
> 
> That and I'm always using the compound so removing it would be really silly in my case.


Will definitely check out the clamp style knurler. For comparison, here’s the original compound on the 1127.


----------



## middle.road (Mar 4, 2018)

jbolt said:


> I use the mitee bite clamps on mine. They work great for fine tuning. My CXA has a hole in the bottom for a dowel pin which I also use.


Which Mitee Bites did you use?


----------



## jbolt (Mar 4, 2018)

middle.road said:


> Which Mitee Bites did you use?


PN 10201, 5/16-18


----------



## MSD0 (Mar 4, 2018)

jbolt said:


> PN 10201, 5/16-18


I’m planning on using these (PN 10504, 1/4-20). I indicated the side of the tool post and will recheck after a week and see if anything has moved.


----------



## robotwizard (Jun 3, 2018)

davidpbest said:


> You'll partially defeat the purpose of improving rigidity if you use t-nuts.   I tried that approach first, and measurements were not gratifying.   Here is what I ended up doing:
> 
> https://www.flickr.com/photos/davidpbest/albums/72157684102384825



Not much choice on the 1127 as it has t-slots on top of cross slide. I guess one could drill and tap holes further inboard, but would be less effective and could only drill in about 1/2"


----------



## MSD0 (Jun 4, 2018)

robotwizard said:


> Not much choice on the 1127 as it has t-slots on top of cross slide. I guess one could drill and tap holes further inboard, but would be less effective and could only drill in about 1/2"


The t-slots have worked out fine on the 1127.


----------



## wrmiller (Jun 4, 2018)

MSD0 said:


> The t-slots have worked out fine on the 1127.



And they should.  You 'could' make some longer/thicker t-nuts to give a bit more distribution to cutting forces. If you need more than that, maybe you need a larger lathe.


----------



## jbolt (Jun 4, 2018)

The t-slots on the 1127 should be more than substantial for the size of the lathe. 

On my PM-1440GT the compound is held on with two small and fairly thin t-nuts. This is the weak link for rigidity. To make things worse, in the 30 degree position one of the t-nuts is within the access hole for the t-nuts.


----------



## wrmiller (Jun 4, 2018)

jbolt said:


> The t-slots on the 1127 should be more than substantial for the size of the lathe.
> 
> On my PM-1440GT the compound is held on with two small and fairly thin t-nuts. This is the weak link for rigidity. To make things worse, in the 30 degree position one of the t-nuts is within the access hole for the t-nuts.
> 
> View attachment 268978



Ouch. Can you make thicker, longer and radiused t-nuts that take up more of that round slot? Just thinking out loud.


----------



## MSD0 (Jun 4, 2018)

wrmiller said:


> And they should.  You 'could' make some longer/thicker t-nuts to give a bit more distribution to cutting forces. If you need more than that, maybe you need a larger lathe.


That’s actually what I ended up doing.


----------

