# Lathe chuck backstop



## NC Rick (Dec 21, 2020)

Hi folks, my first post in this part of the site.  My skills pale in comparison to what so many of you do but I thought I'd shar my mostly success.  I have been trying to come up with a working design amd since I don't do cad, am not too creative or smart I have really struggled through the concepts and implementation.  Anyhow, my second iteration here seems good with one problem due to poor planning.


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## francist (Dec 21, 2020)

Interesting idea. I have one that threads through the spindle to accomplish the same thing (if I understand your concept properly) but I can see where this way might be useful too. Nice execution 

-frank


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## NC Rick (Dec 21, 2020)

francist said:


> Interesting idea. I have one that threads through the spindle to accomplish the same thing (if I understand your concept properly) but I can see where this way might be useful too. Nice execution
> 
> -frank


Thanks Frank!  I had a simple through the spindle of my prior lathe (delta 10") but on this particular SouthBend, the back of the spindle to the nose of the chuck is a bit over 30" And I want something that can come in and out quickly and not be too cumbersome to use or store.  My execution is a little off since I didn't draw it first.  I kinda ran out of room for the clamping detail which while it works is not as good as I would have liked.


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## jeff_g1137 (Dec 21, 2020)

Hi
Good idea, i like it, i will get round to making one.
Jeff from the UK


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## DavidR8 (Dec 21, 2020)

I like it Rick.
Is it held in place by the work piece?


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## NC Rick (Dec 21, 2020)

Good eye David!  I don't want it swimming around while I do setups so it has an internal wedging system which can be tightened by the S.H.C. Screw below one of the jaws.  I barely had room for it. Some kind of a drawing or cad thingy would have exposed my failure prior to all the aluminum removal.  It works but I would have preferred more thread depth.  It works great!


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## NC Rick (Dec 21, 2020)

jeff_g1137 said:


> Hi
> Good idea, i like it, i will get round to making one.
> Jeff from the UK


Jeff, reading your post,  I couldn't help thinking of my friend and coworker Jeff Isherwood who was also from Manchester.  Sadly, he has now passed but I am very happily reminded of him particularly along with the many wonderful people I have known in England.  He is the person who in the 1970s introduced me to the delicious beer up in the north of England. Machining, electronics, motorbikes  and philosophy were amongst is passion. I recall sitting with he and his wife for a meal of roast beef and Yorkshire pudding. I hope you and your country folk stay safe and I look forward to the day I can travel back there.


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## akjeff (Jan 5, 2021)

Late to the party, and just saw this one. Nice job Rick!


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## olf20 (Jan 12, 2021)

Nice! I've been looking for something to do the same thing. Do you have a picture with
the device out of the chuck? 
Never mind I saw the details in you second picture.
olf20 / Bob


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## NC Rick (Jan 13, 2021)

olf20 said:


> Nice! I've been looking for something to do the same thing. Do you have a picture with
> the device out of the chuck?
> Never mind I saw the details in you second picture.
> olf20 / Bob


Bob,
that photo doesn't show the front actuated wedge holding the stop in place after installation.

I have been using it frequently, it was a worthwhile project for me.


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## Philco (Nov 22, 2021)

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


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## NC Rick (Nov 22, 2021)

Philco said:


> 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.
> ...


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.


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## Philco (Nov 22, 2021)

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.


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## NC Rick (Nov 24, 2021)

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.


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## sycle1 (Nov 24, 2021)

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.


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## Philco (Nov 25, 2021)

Philco said:


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


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## Dan Krager (Dec 2, 2021)

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


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## vtcnc (Dec 21, 2021)

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?


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## NC Rick (Dec 25, 2021)

vtcnc said:


> 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!


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## Winegrower (Dec 25, 2021)

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.


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## NC Rick (Dec 25, 2021)

Winegrower said:


> 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.


I thought about that.  I use my collet changer as a stop at times.  Unfortunately the Royal collet adapter won’t fit through the chuck body on my 8” chuck.  It will on the 10” chuck but I like running the smaller chuck most times.  I’d like to have something that installs deeper because of one repetitive job I do that needs the 2” diameter part to go deeper in the spindle.


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## Charles scozzari (Mar 23, 2022)

Great work.This is a must have tool.


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## Janderso (Mar 23, 2022)

NC Rick said:


> I don't do cad, am not too creative or smart I have really struggled through the concepts


Rick,
I too am late to this party.
After reading your initial thread, I would argue with your statement.
It seems to me you do have a creative flair.
Many of us don't know or have CAD. You are not alone.
Well done.


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