Securing base plate for QCTP to PM1340?

[chiroone]

I purchased a Bostar QCTP, I milled the base plate to fit in the PM1340, but I am unsure how to secure it. The tool post that came with the machine used 2 set screws to secure the base, but I’m not sure how to do it with the Bostar because it does not have the provision for these , do I need to do the same thing, that is drill the plate and tap it foe for some set screws?

 

[BtoVin83]

you won't need those, you need to be able to slide the TP in the compound for adjustments.

 

[chiroone]

I really can’t see how that is possible, it’s a firm fit, but not firm enough to hold when it is in the cutting mode. Here is a picture so you understand what I’m talking about, I’m talking about the black baseIt’s a tight fit but not that tight that it won’t move

 

[BtoVin83]

Your base plate should not stick above the compound. When you tighten the TP nut it clamps the TP housing to the top of the compound slide

 

[benmychree]

The thing that secures the tool post to the compound rest is the friction between the QCTP and the compound, all that is necessary is to tighten it down quite firmly, on my 19" Regal, I have a box wrench with a 3' piece of pipe, without the pipe, it can move under agressive cutting forces.

 

[BtoVin83]

Heysus, I ran a 32' Mazak and just used a box wrench on the nut. It never moved, well maybe in a crash but not very much.

 

[darkzero]

Here's a pic of what BtoVin is talking about. The top of the t-nut needs to be below the top surface of your compound slide, if not it will never tighten. The t-nut does not need to be a really tight fit in the slot, the use of a t-nut is for allowing you position the tool post off to the side when needed. The top flange nut pulls on the t-nut & is what does the tightening. Looking at your photo it looks like your nut is loose. If that's as far as it threads down, that needs to be fixed.

 

[chiroone]

Darkzero, You hit the nail right on the head, t-nut profile is actually above the compound and by quite a bit, I think if I can mill that down, we should have a perfect fit. Thanks so much for the feedback

 

[BtoVin83]

The reason the 4 way post uses set screws is that when rotating the tool post you have to loosen the tie down nut. The set screws allow the base plate to remain in position so you don't lose registration.

 

[chiroone]

OK, I took everyone’s advice and mill down the surface of the T- nut. Worked like a charm, the thing is locked in their tight as can be. Thanks everyone for your advice