How to hold small workpiece?

[kad2kam]

I have to mill few hundred of small blocks out of ABS sheet using 2D prog. Part is fairly simple and size is about 6mm cube having little corner radius. I'm trying to machine multi-pieces right thru out of a large sheet but problem is part moves and gets damaged at the end of the cut because no clamping left. Could someone advise the best strategy to machine without damaging the parts. Thanks in advance.

Kevin

[Chombie]

Try using tabs, rout thru in some ares and not others and clean them up by hand. make tabs as thin as you can and you may be able to snap them off clean

[kad2kam]

I thought so but visual appearnace on the part surface is very important and part itself is so small that not much left for routing once I leave some tabs on.

[Chombie]

How about 2 passes do tabs on the first pass, than cut tabs on the second pass. and also you might try contact cement. Are you using a down shear cutter I find that helps hold parts in place

[metlmunchr]

Heres a way I've done some thin sheet aluminum parts in the past. mill the profile, leaving the entire bottom of the slot intact but just a few thousandths thick. then drop down thru the part and cut it free with the exception of a small tab midway on each side. When you remove the sheet, you can turn it over and cut the parts free of the tabs with an exacto knife. Having the tabs NOT at corners makes this fairly easy.

[buscht]

Some more options:

1. Leave about .002 material and run the blank through a sander (Performax drum sander) to seperate the parts from the blank.

2. Use carpet tape to hold down the sheet, cut normally, then pull the parts off of the carpet tape.

T

[Klox]

I have seen it done like Metlmuncher says, it works! Otherwise it can be stacked and cut with a wire-edm.

Klox

[Graham S]

I like buscht's 1st suggestion. You could do that in a mill, possibly adding extra clamping in the form of wax so the parts don't fly off.

Klox, edm ABS? That's a new trick

[cadcam]

I like buscht's #2 suggestion. I have done this dons of times.
use 3m doulbe sided tape.

Use to do this for samll inserts for wax investment molds.

[turmite]

Originally Posted by Klox I have seen it done like Metlmuncher says, it works! Otherwise it can be stacked and cut with a wire-edm. Klox

Klox can you edm plastic? I am probably showing my ignorance here but I have plenty of it to go around. I though ABS was a type of plastic and if it isn't be gentle when you tell me.

Mike

[Klox]

Hey guys, sorry i read this thread while wearing my welding helmet! LOL! No you can't edm plastic!
My humble apologies........

Klox