Holding thin parts for machining .........

[toolznthings]

Hi All,

A quick way to hold thin materials to machine or engrave on cnc or manual mills works well with double side tape. Such as McMaster 7602A53 tape.
You can adhere to any smooth surface such as melamine coated particle board, aluminum or a solid face 1-2-3 block. The last I did for diamond engraving a name plate. Clean both surfaces with acetone and apply pressure with clamp or vice to affix part. The trick to removing the part is applying moderate heat with a hot air gun to release the bond. It does not take much to start the release of the part.

Brian

 

[Swifty]

Hi Brian, I have used that method on quite a few occasions. I use what is known here as carpet tape, it's very thin and sticks very well, the problem is always in removing it.

Paul.

 

[rklopp]

I heat my substrate on a hot plate and apply a little hot-melt glue, which I the screed off using a fine-tooth notched trowel, like for linoleum adhesive. Then weight the workpiece with flat metal scraps. Once cool, I machine the part. To release, I reheat, and dissolve the residual glue in a pot of hot oil. This method holds much better than double-stick tape, and releases more easily, but cleanup is a bit messier. Do not overheat the oil. DAMHIKT.

 

[kiwi2]

The best solvent for most of these types of glue is kerosine which I think is called parafin oil in the UK. It works fine cold.

 

[kadora]

I use low melting point 5 minute epoxy . Advantage - there is possibility
to move glued parts to desired position and then let them dry.
After machining just heat parts with mini torch.
Kadora

 

[toolznthings]

Hi Brian, I have used that method on quite a few occasions. I use what is known here as carpet tape, it's very thin and sticks very well, the problem is always in removing it.

Paul.

Hi Paul,

That was the big problem removing the parts until finding out the heat method. Give it a try.
All good tips !
Brian

 

[GWRdriver]

I have held many a small or odd part using "Superglue." It's not completely impact resistant so if the work involves an interrupted cut I have to go lightly.

 

[jwcnc1911]

I use vacuum fixtures from time to time. No clean up at all, just flip a switch. This is primarily for flat or plate material. For flat parts, you can make a DIY vacuum fixture very easily with a small piece of aluminum and a shopvac and a bit of tubing. Google "vacuum fixture" to get an idea and go from there. For small or tiny non-flat or complex parts I pretty much always make a fixture.

I guess fixturing is my mindset tho.

 

[nj111]

I've found that those brown liquid Polyurethane Wood adhesives like "Gorilla Glue" or an equivalent work really well. Just a thin layer with pressure applied whilst it sets. (30 mins) It's very strong (and expands to fill any gaps). It resists cutting forces well but will fail when heated with a hot air gun or gently with a blow torch without any damage. With aluminium there is no adhesive residue left on the material at all.
I've always used coolant on parts held like this, possibly it could fail during machining if not kept reasonably cool.

 

[goldstar31]

There is a lot of things that are worth considering. The first is the famous bell chuck for holding odd larger things. The second is a box containing the awkward article and set in fibre glass resin or even tar. A bit mucky, perhaps but for first operation stuff, it is worth the 'clart'
The recommendations for 'modern resins' has my agreement but so is something made up of a mixture of resin, shellac and beeswax. Sort of stuff that holds glass and emery on to things as well as faceplates etc.

Probably the best is either or both the 'thinpiece vice' beloved of Tubal Cain and soft solder onto a lump that is going to be hammered repeatedly on a faceplate. Of course, there is the simple little 'tin tacks' into a piece of ply or mdf wood.

The old boys- of which I am one- use glues to hold bits of emery cloth onto wooden tongs to polish out ridges in their turnings- Of course, you wont tell anyone- will you?

Norman

 

[mu38&Bg#]

For engraving and light machining I use candle wax on an aluminum plate that fits my vise jaws. There are waxes made just for this though.

I was going to try this next time I had something larger. http://blog.cnccookbook.com/2012/09/04/super-simple-keyed-fixtures-for-cnc-mills/

 

[doug tyler]

This is what I've always used. I've been able to make my own .005 thick washers using it.

http://www.miteebite.com/products/mitee_grip_e.html

I believe the holding force is 40 psi.

 

[toolznthings]

Thanks for the post. Did not know that was still available. Never used it, but have always understood that it works well, as you mentioned.