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

[Bob Korves]

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!

 

[davidpbest]

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

 

[Jake P]

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?

 

[matthewsx]

I think this is the dimension:

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

Just sayin....

JOhn

 

[mksj]

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.

 

[Jake P]

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.

 

[davidpbest]

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.

 

[Jake P]

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!