Thread: adjustable tailstock for 4th axis

Make some oversized keys and take a skim cut in the t-slot. Might not be able to do it the full length, so add a little relief notch at the ends so it won't wedge in as bad if you push it too far. Or lock a t-nut there as a stop.

Originally Posted by empwoer

your t slot nuts are that tight to the slots? maybe i'm missing something, how do you get it to stay aligned that tight in t slots?

The t-slots don't need to be tight, just clean. Once I have my tailstock in position I push it against the side of the t-slot taking up any play, same for the 4th axis when I am bolting it to the table. This works with my tailstock because I took the time to fit it to my 4th axis and table by scraping it in.

I REALLY think installing your 4th on linear rails and blocks would be an imperial cluster fuck. If you can't get the t-slots to work what makes you think adding all the extra movement will make it more accurate? Especially when you push against your 4th with 500-1000 lbs of force, or whatever it is rated for.

WHAT ACCURACY ARE YOU TRYING TO ACHIEVE?

Here is a photo of my setup. On average it takes me 20 seconds from the machine stopping to pushing the green button when swapping fixtures. I push against my 4th with 360lbs, which is the maximum rated force for it.

Originally Posted by empwoer

any suggestions on how i'd go about building something on linear rails?

If you don't want to flip it over and either drill and tap some bolt holes or keyway slots in the bottom of your tailstock, then maybe you could just slip some cold rolled plate up agginst your tailstock on both sides and clamp down, just allowing your tailstock to slide between them?

... and this may be a good plan too as if you had your tailstock keyed and your headstock keyed, and the two were not in complete agreeance, you would have a nightmare, especially as you got closer together. Where the cold rolled guides would be added after you were indicated in, and should be pretty true.

Now this ass_u_mes that the sides of your tailstock are straight and square as well.
It is possible that you might need to mill those in true if they are rough cast.
They would need to be straight, but not perfectly centered.
You could prolly extend the quill to indicate off of.


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