# What is the toolpost T-nut size required for 1340GT?



## diamond (Jul 7, 2018)

I am about to purchase an Aloris BXA tool post for the 1340GT I am anxiously awaiting delivery on.

Aloris standard is:
BXA                       5/8”                      2-1/4”

I've sent a note off to QMT but I bet someone here can answer this real quick.   Just want to confirm it takes that standard before I order.   

Also sorry if this is answered elsewhere.   I did some searching & found great info on tool posts but not an answer to this direct question.

Thanks!


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## [X]Outlaw (Jul 7, 2018)

I can't remember off hand the dimensions of the T nut slot. My Dorian BXA came with a blank nut and I machined it to machine the lathe's T nut slot for a nice snug fit. Quick work once you have a mill.

Chevy


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## mksj (Jul 7, 2018)

The 1340GT T-Slot is approximately 2" wide x 5/8" tall x 3" long. The standard T-nut is typically supplied is a bit oversized to accommodate it being machined to fit as this can vary from machine to machine.


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## bss1 (Jul 7, 2018)

I purchased an Aloris tool post for my PM1340GT from Matt at QMT. They machined the nut to fit before shipping it out. His price for the tool post was very reasonable.


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## bretthl (Jul 7, 2018)

diamond said:


> I am about to purchase an Aloris BXA tool post for the 1340GT I am anxiously awaiting delivery on.
> 
> Aloris standard is:
> BXA                       5/8”                      2-1/4”
> ...



Here is what I measured on my PM 1340GT.  This is the nut, not the slot dimensions.


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## bretthl (Jul 7, 2018)

On a further note you may be able to use the T-nut that comes with the 1340.  You may have to cut a new T-post stud (I did that on mine).


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## ptrotter (Jul 7, 2018)

I also bought my Aloris from Matt with the PM-1340GT and he machined the nut as well.


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## diamond (Jul 9, 2018)

Thanks all for the replies.  You can see how much of a noob I am at this and how much I've got to learn.  Appreciate this site for that!  I understand now it's pretty much standard to mill to fit the machine.   I may go ahead and get the Aloris from Matt then so it can be shipped with the lathe.


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## Bob Korves (Jul 9, 2018)

I suggest making your own t-nuts to fit the ways like you want them to fit.  Store bought ones are compromise sized to fit many machines.  Use common mild steel, do not harden them.  Hardened t-nuts can damage t-slots.  Round and deburr all edges and corners carefully and well.  T-slots are part of the precision of the machine, and dinging, scratching, and distorting them damages the machine.  Nicks, dings, swarf, rust, grime, and burs also make the slots more frustrating to use.  Take care of those nice new slots!  You do not mention if you are a newbie on a milling machine, but if so then making some t-nuts is a great first project to get used to using the machine.


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## diamond (Jul 9, 2018)

Definitely a newbie across the board when it comes to machining.   Thanks for the advice Bob.


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## Bob Korves (Jul 9, 2018)

diamond said:


> Definitely a newbie across the board when it comes to machining.   Thanks for the advice Bob.


Something to watch out for when making your first t-nuts is the height of the nut above the step.  There is always some play in a t-slot.  When you pull up on a bolt or nut in the t-slot, the top of the t-nut must not protrude above the table.  Yes, that sounds stupidly simple and reasonable, but it is a common problem that causes many newbies grief.  When you tighten down on the bolt or stud and the t-nut protrudes, it locks against the bottom of the vise or whatever you are bolting down.  The bolt is tight, but it is not clamping the work or vise down to the table.  I aim for the top of the t-nut to be about .030" or more below the top of the table when clamped, so swarf does not become a problem.  Have fun!


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## davidpbest (Jul 11, 2018)

Here are the dimensions I took from the T-nut supplied with the 1340.


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## Jake P (Aug 7, 2021)

davidpbest said:


> Here are the dimensions I took from the T-nut supplied with the 1340.
> 
> View attachment 271709


Does anyone know if this dimension has changed with more recent 1340GT's?  

Would it be safe to manufacture this now to these measurements while I wait for my 1340GT?


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## matthewsx (Aug 7, 2021)

I think this is the dimension:



			https://www.precisionmatthews.com/shop/1054t-precision-knee-milling-machines/
		


Just sayin....

JOhn


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## mksj (Aug 7, 2021)

Unlikely that the dimensions have changed, but something you want to check the fit to your particular lathe for final fitment. Also  the tool post will vary somewhat depending on the QCTP you buy, the M16 thread is not a typical thread for a BXA tool post (it is for the lantern type). If you buy the QCTP from PM, it was my understanding that they would machine the foot for you.


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## Jake P (Aug 7, 2021)

mksj said:


> Unlikely that the dimensions have changed, but something you want to check the fit to your particular lathe for final fitment. Also  the tool post will vary somewhat depending on the QCTP you buy, the M16 thread is not a typical thread for a BXA tool post (it is for the lantern type). If you buy the QCTP from PM, it was my understanding that they would machine the foot for you.


Thanks Mark.  I've already got an Aloris BXA that I got here from another member, so that's a known.


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## davidpbest (Aug 7, 2021)

Jake, attached are the precise measurements of the T-nut that I fitted to the compound of my PM-1340.  I think you would be safe roughing to 0.010” oversized and fitting upon delivery. Just make sure the “T” leg segment sits slightly below the top surface of the compound when the T-nut is pulled upward - such that the QCTP bottom is pulled down firmly against the top face of the compound.


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## Jake P (Aug 7, 2021)

davidpbest said:


> Jake, attached are the precise measurements of the T-nut that I fitted to the compound of my PM-1340.  I think you would be safe roughing to 0.010” oversized and fitting upon delivery. Just make sure the “T” leg segment sits slightly below the top surface of the compound when the T-nut is pulled upward - such that the QCTP bottom is pulled down firmly against the top face of the compound.


Thanks for the additional info David!


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