# Quick QC tool post question



## DeepLogic (Jun 3, 2021)

I'm looking to add a QC tool post to my Craftsman/Atlas 12" lathe. Am I right in assuming I will no longer be able to use all my 1/4" tool bits with the QC? Have to switch to 1/2"?
Thanks for any advice.


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## erikmannie (Jun 3, 2021)

You can shim them.


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## DeepLogic (Jun 3, 2021)

Oh, that would help. Are they much more prone to chatter if I go that way?


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## NC Rick (Jun 3, 2021)

The qc tool post holders (assuming AXA for that sized lathe) will have height adjustment to allow you to get your center height set correctly.  Scheck this out while mounting the tool post up.


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## erikmannie (Jun 3, 2021)

DeepLogic said:


> Oh, that would help. Are they much more prone to chatter if I go that way?



A lot of machinists use 4 position tool posts, usually with shims. 

I have never used a shim in this application, so I don’t know if chatter is a problem.


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## Doug Gray (Jun 3, 2021)

Shim under the entire length of the tool. An HSS tool blank works well. make sure everything is nice and clean when mounting your tools, IE no chips/ or dust.


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## DeepLogic (Jun 3, 2021)

Thanks so much for the quick replies everyone. I ordered my QC and some 1/2" bit too. Can't wait to try this out.


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## erikmannie (Jun 4, 2021)

Did you get AXA or BXA?


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## benmychree (Jun 4, 2021)

A 1/2" tool bit requires a lot of grinding; you would be better off using smaller bits, one can do a lot of cutting with 1/4" tool bits, and the Atlas is not such a lathe for heavy cutting that would require bits as large as 1/2".


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## T Bredehoft (Jun 4, 2021)

I made an 8 pitch Acme external threading tool from 1/8" square HHS, let it into (cut a 1/8" keyway in the top of) a piece of 1/4" key-stock. It worked a charm and very little grinding, compared.


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## Moderatemixed (Jun 4, 2021)

My QCTP is an old Armstrong. It takes AXA sized tool holders and it has done well with 3/8 and 1/2 inch tools. Shims are no big deal o long as the tool is adequately supported (I know that I am stating the obvious). Having chased rigidity issues with my Atlas 10F for over a year I did find, although marginal, there to be a bit less chatter when the tool was held without any shims. You could make an adapter sleeve that holds a 1/4 inch tool and has a 3/8 to 1/2 shank. Or just migrate to the dark side and learn to love the 3/8 and 1/2 tooling, lol. 

Cheers. 

Derek


Sent from my iPad using Tapatalk


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## DeepLogic (Jun 4, 2021)

I did get the AXA wedge type. I'm really new to all this stuff, and have only finished a couple of projects so far. Chatter seemed to be a common issue, so I'm hoping this will help with that. I've learned a lot about getting gib screws adjusted properly to keep the play out of things. Really glad to get good advice like this, and can still get use from my existing bits.


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## DeepLogic (Jun 4, 2021)

Here's my first try with the lathe. I'm restoring a very old, small wood lathe, so I turned down fresh surfaces on the heavily rusted flat belt pulley, and made a brass oil cup to replace the simple oil hole that was there. It took me forever, but I learned a lot, and got much more comfortable with the machine. Last time I used a lathe was in school shop class back in the very early 70's.


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## NC Rick (Jun 4, 2021)

DeepLogic said:


> Here's my first try with the lathe. I'm restoring a very old, small wood lathe, so I turned down fresh surfaces on the heavily rusted flat belt pulley, and made a brass oil cup to replace the simple oil hole that was there. It took me forever, but I learned a lot, and got much more comfortable with the machine. Last time I used a lathe was in school shop class back in the very early 70's.
> 
> View attachment 368127


That is beautiful work and of the kind I really like!  Bringing a new life to good old tools is a noble cause.


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## DeepLogic (Jun 4, 2021)

I just can't resist good old stuff like this. This lathe was in a machinist shop, and the woman said her father had kept it all these years. It was headed for the dumpster when she decided to keep it. What a pretty little thing, and surprising stout (and tight).


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## markba633csi (Jun 4, 2021)

An AXA toolpost is perfect for a 12" Atlas and should easily be able to accommodate 1/4" and 5/16" tool bits.  3/8" is pushin' it.  1/2" no way, ho-zay
-Mark


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## NC Rick (Jun 4, 2021)

I use mostly 3/8 in my bxa holders.  1/2” if I need the biggness.

5/16” is good on that sized lathe I would think.  Grinding time makes me nuts.


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## NC Rick (Jun 4, 2021)

DeepLogic said:


> I just can't resist good old stuff like this. This lathe was in a machinist shop, and the woman said her father had kept it all these years. It was headed for the dumpster when she decided to keep it. What a pretty little thing, and surprising stout (and tight).
> 
> View attachment 368133


Please post photos of the finished product!


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## mikey (Jun 4, 2021)

NC Rick said:


> I use mostly 3/8 in my bxa holders.  1/2” if I need the biggness.
> 
> 5/16” is good on that sized lathe I would think.  Grinding time makes me nuts.



I use 3/8" bits, too. I have a Sherline and an Emco Super 11 and use the same 3/8" bits on both lathes. I cannot adjust my AXA tool post low enough to use 1/2" tools unless they're modified. 1/4" bit, shimmed up, will work fine; they are more than rigid enough for even heavy work but you must keep overhang to a minimum.


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## wa5cab (Jun 5, 2021)

The AXA tool holders are designed to hold either 1/2" or 3/8" square cutters or cutter holders.  The row of set screws is centered 7/32" from the bottom of the slot (or at least it was in the original Yuasa design).  Which is 1/32" either side of the center-line of either3/8" or 1/2" square holders or blanks.  They have adequate vertical adjustment range to put 1/4" to 1/2" sizes on center.  So normally, there is no reason for using shims under cutters in an AXA holder.  The reason for using shims on a 4-way or 4 position turret tool holder is that they have no other vertical adjustment means.  

One good reason to standardize on the 3/8" square cutters instead of 1/2" square ones is that at least last time I bothered to check, there was a significant price jump between 3/8" and 1/2".


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## wa5cab (Jun 6, 2021)

Deeplogic,

The AXA tool holders are designed for 3/8" or 1/2" square tooling.  However, they will hold 1/4" square cutters or cutter holders if you must.  I would recommend that you cut a piece of 1/4" square key stock into lengths equal to the width of the AXA holders for however many holders you have that you wish  to load 1/4" square cutters into.  Put a spacer into each holder with the actual cutter outboard of it.

But unless you have or plan to buy a 6" lathe, you should plan to eventually phase out the 1/4" tooling.


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## akjeff (Jun 8, 2021)

I've found 1/2" shank tool holders to work fine in my AXA on a 12x36 lathe. While the 1/2" is likely overkill, I like the added rigidity as I have to extend my holders out in order to "reach past" the DRO scale that's on the chuck side of the cross slide. This, when I need to work up close to the chuck. Otherwise, I'd likely go with 3/8" shanks.


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## wa5cab (Jun 11, 2021)

OK.  That would be a valid reason for using the usually more expensive 1/2" cutters.


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