How to hold cutout work (n00b question)

[MechanoMan]

OK, say I've got a CNC mill and a Modulator Work Holding System from High Tech Systems. Say there's a disk I need to cut out of flat aluminum stock. Just an example problem. I don't actually need a bunch of disks.

Now I can secure the stock no problem. I'll secure it on MDF or acrylic scrap as spoil board. But when I send the cutter in to free the disk from the stock, that thing will become free, bounce around and shatter a nice carbide endmill.

If I clamp it, then the cutter will strike the clamp sooner or later, unless I have it do one side, stop cutting, place like a rocker clamp on the work over an area that will not be seeing the cutter again, and tell it to cut out the other side. Sounds possible though I'm not sure how to explain this to the CAM tool.

I can use double-sided tape, the fiberglass-reinforced Duck brand, this worked nicely with acrylic but the lubricant/coolant I used for aluminum quickly ruined the tape's stick and the work freed itself.

I could glue it. It's a mess to remove the glue, but I could.

I can leave tabs- like the sprues that hold a bunch of model parts in one rack together. Then... Dremel I guess. Takes awhile and difficult to finish away or provide tight tolerances on.

Sometimes my work has a hole in it. I could always stop the machine prior to cutting the work free, and put a bolt or screw in to screw it to the spoil board. But there's no threads beneath to screw a bolt into, and the spoil's not normally thick enough to hold a screw either. Actually without a pilot hole any of the larger holes I make might not take a large screw very well.

What's really the practical option(s) here? Is there a good primer on the web for this?

[ALLtra Mach]

If you have A hole in the part theres your answer.
You use a "Spoiler" as your calling it, drill and tap it in the location of usually at least two holes, then use flat head cap screws to hold the part in position. Then you profile it out.

Another option is to profile it out of thicker material, cut the profile into a set of aluminum vise jaws and face the extra off. Or profile 3/4 the way down, then flip and do the other 1/4.

[Lew Hartswick]

For fairly large peices use a vacuum chuck. the clamping force is going to
depend on the area times aprox. 14 lb per sq inch.
...lew...

[Fixittt]

or use bridges or tabs that dont get cut. make them thin so that they hold the part in the material and can be easily removed later. This is how we do it with wax, and I understand wax is not metal. but the same principals apply. Dremel cutoff wheel and a belt sander can remove all traces of the bridges

[mc-motorsports]

hang your plate out of a bench vice so the part can fall out the bottom... But this is going to leave a tang where the EM started and ended, either grind if off or finish the OD on a lathe.

That's if your part requires additional milling opps before cutting out the disk or puck. If it's just an aluminum disk, get some bar stock and use a cut-off tool in a lathe. Or pay someone to CNC punch them. If you only have a mill, use a 3 jaw chuck clamped to the milling table, chuck some bar stock vertically and use a slotting saw.