Help needed holding thin non-magnetic stock on a magnetic chuck

Patrice Lemée

Patrice Lemée

Joined
Aug 13, 2002
Messages
5,703
I thought I'd start a separate thread cause I've never seen much on this topic.

I tried surfacing thin stock (stainless steel) on the surface grinder last night, holding it in a small tool vise with shims so it was a little above the top of the vise. The vise was then held with the mag chuck. Well it didn't work at all, the stock kept moving a little and screwing my parallel.

Any tips that could help? How do you guys do it?

Thanks.
 
Interesting choice of topic for this forum Patrice! Did you have your coffee this morning? :-)
 
Super Glue works quite well if you are only dusting off the top, say .005-.100. Has worked well for me over the years.
S. Dunn
 
Double sided tape. Works every time for me. I put a piece on my magnetic chuck then a small piece of carbon steel in front of the tape which butts right up to the material to be ground to help keep it from moving. This of course will only work with smaller items, don't think it would be very good for larger items.

Sean
 
ScottRoush said:
Interesting choice of topic for this forum Patrice! Did you have your coffee this morning? :-)
Click to expand...

Ah crap! :o Sorry guys. If a mod could move this to shoptalk that would be great. :o

Thanks for all the advices, I will give all those a try. :thumbup: It is mostly for spacers and guards for now.
 
I would file/drill an appropriate sized hole in a larger but thinner piece of steel then put the steel on the chuck with the guard in the cut out. If fitted correctly there should be no movement. You want as large a surface area as possible for the magnet to work. I have done this once or twice and it works pretty well. Obviously shallow cuts are required.
 
Patrice,

I've had to tackle this same problem a few years ago. I tried many things, but one worked best by far.

They are lapidary fixatives, basically a thin, low melting point wax (solid when room temp, consistency of CA glue when liquid).

There are two types, a water-release, and solvent-release. The solvent release is a slightly stronger bond.

They are typically used for holding optics and gemstones in lapidary fixtures, but they work amazingly for holding small, fragile parts for surface grinding and even machining operations. If done correctly, the bond is nearly as strong as epoxy, but washes away with tap water, and your part falls free.

If you are grinding with coolant, the solvent wash versions will work. They also make sheets that you can place and then bake the parts together at low temp.

I have used these compounds successfully to fix stainless, aluminum, and titanium sheets to a ground steel bar for surface grinding or precision machining operations, and was able to hold +/- .001" or better tolerance.


edit: This is the exact stuff I used, I remember it now that I found their site...

http://www.emsdiasum.com/microscopy/products/materials/adhesives.aspx


This stuff is a bit $$$, but I wouldn't mind having some around again, so maybe we could split an order and I could forward your half up to you from the states. A stick goes quite a long way, a single drop is enough many times.
 
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Double sided carpet tape will also work.

Stan
 
I have a piece of 6x18 1/4" steel that I bolt the piece to. As long as I have a couple corners that I can countersink and run a machine screw through, I've not heard of any problems from the machine shop that does the surface grinding for me. I've done this for everything from knife stock to titanium spacers for a folder.
 
Three more methods that I'll try. Thanks guys.

Vintage, Let me try a few of the other methods first and get my “play money” fund refurbished and I'll contact you to see if we can do that.

Claudio, that fixture looks very cool but I am afraid that I could not reproduce it with my limited machining experience. :( Too bad cause it looks like it works great.
 
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