Pm1228 In Born

I like it!!! Could actually do a "mobile" spider so it doesn't rise either... Thanks for sharing Bolt!
 
As long as there is a little upward pressure on the stock that is being supported it won't jump. Really long thin stock may need more support. Years ago at a shop I worked at we made some 16 foot long tie rods out a 1/2 steel rod. We supported the entire length in a pipe to keep it under control.
 
Louis,

What's said about backing off to much when unlocking, is true and can be somewhat controlled. Unfortunately that is only one half of the problem.

This lathe the access hole just happens to be lined up with the T nut if the compound is set @ 45*. With this setting the T nut is centered in the hole, floating . Try to lock down the compound slide, the nut turns freely, nothing there to capture it. Sure you can futzs around working on both lock down screws and get it to work ....... who needs that ?

Made a guide plug that solves the problem. I did forget to mention an item in the write up. I ended up putting a stud in the 1/4 x 20 hole to keep the T nut from dropping below the circular groove, if too loose.


@Buggy Chief
No pictures the lathe is back together, here is a drawing for a reference, . As seen it is a simple project, get stuck or have a question PM me

greg
View attachment 140132

Greg,

I have the same problem and its becoming very frustrating.... however I am not fully following what you did to fix it.

I believe you made a slotted plug that fits into the access hole of the compound. But if the slot in the plug is straight how does the compound rotate as there would be interference between the t-nut and the slot as the compound rotates. I also don't understand the purpose of the screw.

Apologize if I am not understanding what you did.

I was also thinking about a solution and the only thing I could think of was replicating the t-slot radius with a plug similar to what I think you have done.. but rather than straight slot it would have the same slot radius as the compound.
 
The slot holds the alignment enough for the T nut to fug its way across the open space. Remove the cross slide flip it upside and see for yourself what's going on. With the compound slide @ the 45* setting you are fighting two problems. Locking the compound slide the T can spin 360 , can get side ways and jams the compound slide so it only moves about a half inch in each direction.
That happens when the T nut is at a 90 to the T slots on either side of the hole or gap.

Two things are going on
1 the T nut not hitting the T slot, milling a 9/16 slot took care of that, and captures the T nut. Allowing the T nut to lock the compound slide @ 45*.
2 the T nut can be to lose, and become low and jam the compound slide. An allen up thru the bottom makes an adjustable stop to control that.

Your thoughts replicating the t-slot radius with a plug, is proper. I think if you put that on paper you could find the distance of the radius, is small enough to not be needed. I took the easy way out, no rotary table here for the cheater I made..
hope this helps
Greg
 
The original T-nuts have flat sides on the bottom but they have a cylindrical feature that rides in the
top of the slot. This cylindrical top is what allows the T-nut to rotate once it gets to the access hole.

If you make T-nuts with flats on the bottom and top of the T-nut, then when you get
to the access hole the top part of the T-nut will keep it aligned in the top slot. This has been
enough for me to avoid the problem of getting the compound stuck at 45 degrees.

Now this doesn't handle the case if you loosen the locking screws so much that the T-nut drops
below the slot once it reaches the access hole. If you wanted to avoid that you could turn a
flat bottomed plug for the access hole. It wouldn't have to be a close fit on the diameter, but
it would be better if the height matched the bottom of the T-slot. So far I haven't needed that
since I just loosen the locking screws about 1/2 of a turn.
 
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