# lathe chuck backstop



## PeterT (Feb 13, 2018)

Did you ever come up with a neat idea, but not act on it. Then one day you see something almost identical commercially available & say, Dangit - that's my idea! And then wonder... maybe I actually saw it in the catalog just flipping pages but didn't pay attention. Then RE-invented a slightly crappier version of what was probably sitting deep in your grey matter stew? LOL

Anyways... I wanted to wait & see how my Shapeways 3DP mag stand flashlight holder thingy turned out. If quality & price was ok I had other gadgets to make. This was one of them. A plastic holder that accommodates inserting 3 parallels so you can create a nice accurate back stop for turning thin pieces to various standoff distances. The back side has molded depressions for mini high strength magnets so the frame stays put. The parallels fit into the slots & are trapped between the chuck body & work. Unfortunately parallels are sold in pairs, not threesomes. But I previously bought this mini length set from LMS for small vise setups a while back, figured I could get another. Even the cheapo ones are not so cheap though. https://littlemachineshop.com/products/product_view.php?ProductID=3946&category=

Lo & behold, Edge sells a similar unit c/w parallels. They secure them with bolts which is probably safer but also fiddly. They integrate a chuck centering feature which I guess is useful. Anyway 149 USD for the kit.
http://www.shars.com/chuck-stop-set

Early bird gets the worm!


----------



## John Conroy (Feb 13, 2018)

I got this idea from Joe Pieczynski on youtube.






I drilled and tapped 6 M6 holes in my 3 jaw chuck and made some stand-off pieces from aluminum. Free and easy to make any height you want.









John


----------



## PeterT (Feb 13, 2018)

That's a good idea. I always assumed the scroll goodies were quite close to the face, but admittedly haven't had too many apart.


----------



## John Conroy (Feb 13, 2018)

I measured the thickness of the front face of the chuck and it's .700" thick. I drilled the holes to a depth of .600" so I have at least 1/2" of threads. I am making some parts for my 8" bench grinder to compensate for shaft runout and this method allows me to achieve parallelism withing a couple of tenths easily. More on that project later.


----------



## Bofobo (Feb 13, 2018)

Ive always just used a piece of stock, pressed tight with the tailstock before tightening the chuck, this is way better!


----------



## Janger (Feb 15, 2018)

Parallels! Interesting idea. So I grabbed some magnets and my 1/2” parallels. Used just two ina T-shape. Pulled the paralllels out after inserting the stock. The magnets are a bit fussy. But it works...


----------



## Janger (Feb 15, 2018)

@Jwest7788 all the photos are rotated again. Due to the upgrade? Fixable at some point? I know you’re really busy right now....


----------



## PeterT (Feb 15, 2018)

You are Ok in a stationary chuck setup like on a mill table, but I'd be apprehensive about the parallels flying out when its spinning if they ever loosened up. That the reason they are tied to something. Bolted to the center piece in the Edge model, trapped within the plastic groove on mine. Permanently bolted in the case of Johns.


----------



## Janger (Feb 16, 2018)

Oh no Peter I took them out after tightening the chuck. Used them for alignment only.


----------

