Lathe chuck backstop

[Philco]

I was thumbing through the shop made tooling and came across this chuck backstop.
NC Rick, this is an interesting concept and looks like it would be quick to set up and quick to remove.
Also like you mentioned a “worthwhile project”
I’m interested in seeing the “The Front Actuated Wedge “ to lock it in place.
Would it be possible to get some pictures of the lock wedge.
You mentioned in post 3 that while the clamping system works, its not as good as you would have liked.
Would you mind elaborating on the clamp and what you would have done differently?
Thanks,Phil

 

[NC Rick]

I was thumbing through the shop made tooling and came across this chuck backstop.
NC Rick, this is an interesting concept and looks like it would be quick to set up and quick to remove.
Also like you mentioned a “worthwhile project”
I’m interested in seeing the “The Front Actuated Wedge “ to lock it in place.
Would it be possible to get some pictures of the lock wedge.
You mentioned in post 3 that while the clamping system works, its not as good as you would have liked.
Would you mind elaborating on the clamp and what you would have done differently?
Thanks,Phil

I was trying not to embarrass myself too bad. With throw myself under the bus for you the clamp is an off center m8 low head SHCS with the tip turned to a 90 degree included angle point which intersects a sideways positioned brass “plunger” which pokes out the side of the backstop. when the screw is turned the angles touch and cause the plunger to be forced out very effectively. The dissatisfaction in my design is because the moron who measured the chuck failed to notice the error of the depth of the plunger just starting to catch the body of the chuck. Me, being that moron, didn’t want to start all over and called it good enough. Design is good. Execution not so much. If that isn’t clear, I can dig it out and take a photo.

 

[Philco]

Thanks NC for responding. After studying the pictures for a while I had actually envisioned a couple of different ways to wedge lock the tool in the bore but it never crossed my mind to lock it with this method.
Yes I would love to see some pictures of the locking set up if you don’t mind but please do it at your convenience.
My son is really good at drawings stuff up in cad.
Hopefully with your pictures and the dimensions of my Lathe he can draw it up for me.
Your design should work in a 4 jaw chuck also. It would be nice to have one for each chuck.
This design looks like it would be even quicker than Jo Pie’s method.

 

[NC Rick]

Those has been a good tool but isn’t universal or perfect. The central stop is super for holding parts without crushing pressure and is adaptable to many optional “accessories”. The clamp is super simple to make. It is like a “v” grove so the part can’t fall out. Plenty of travel and good force.

 

[sycle1]

Great execution NC Rick.
I can see that getting a lot of use.
I will add it to my long list of builds.
Thanks for sharing.

 

[Philco]

Thanks so much NC for sending the pictures. That makes it real clear to see how the wedge works.

 

[Dan Krager]

I have a stop that goes through the spindle, but I like this idea. I cannot quite grasp how the center screw activates a wedging action. I can't see the wedge pieces.

Edit: Please ignore this. I didn't see all the posts for some reason. It's clear and it works.
DanK

 

[vtcnc]

Nice shop made tooling project! I needed something like this recently, but for my four jaw.

Quick question on the plunger lock: is the plunger offset from the center of the locking screw, or aligned with it on centers?

 

[NC Rick]

Nice shop made tooling project! I needed something like this recently, but for my four jaw.

Quick question on the plunger lock: is the plunger offset from the center of the locking screw, or aligned with it on centers?

Aligned on the same centerline. Merry Christmas folks!

 

[Winegrower]

My lathe has an MT5 taper, so I just made that taper, with a giant screw/bolt/stop through it. The taper keeps it locked in place, the screw allows the stop to be positioned at the desired Z location, and could not come out anyway because the part is held in by the chuck jaws and blocks it.