How to secure a small mill cut from flying all over the place

[trialanderror]

I am using a 3mm end mill to cut out a lego head for my son. It has a bit over a 1cm diameter and is going to be the height of the aluminum plate I am milling it on which is about 7mm. How can I secure such a small part from getting all tangled up with the turning end mill when reaching the full 7mm depth?

[txcncman]

I would have run this job in a vise with soft jaws. I would have started with 10mm material and milled the entire part. Then mill a matching pocket into the soft jaws, minus 0.5mm, and flipped the part over and mill the excess material off of the bottom.

[awerby]

It sounds like what you need to do is establish some "bridges" to support the part in the material after the cutting is done. Otherwise, when you cut it loose, it will fly off into the swarf pile. Some CAM programs do this semi-automatically; if yours doesn't, then add them with the CAD software.

Andrew Werby
ComputerSculpture.com — Home Page for Discount Hardware & Software

[trialanderror]

bridges sound like a good idea, I am finally starting to learn how to use mastercam, do they have a feature to add them automatically or should I just draw them? After I guess I would machine out the bridges while clamping the finished shape yah?

Or what about using a strong magnet attached to a vise to keep the part in place during the last 1mm or 2 of machining?

[dertsap]

crazy glue



.

[txcncman]

A magnet? Seems you will struggle with this one for a very long time.

[grg12]

Use bar material instead of plate - for example take a piece of 12mm square bar, secure it upright in vice so that 10mm is sticking out, carve your "head" then cut it off with small circular saw or disc cutter (not sure if i use right name - it's a milling cutter that looks like miniature circular saw blade). What mill du you have? These cutters require low speed.

[TechGuy5002]

Can you drill and tap a hole into the work piece and use a threaded stud to hold in in place?

[trialanderror]

Can you drill and tap a hole into the work piece and use a threaded stud to hold in in place?

This seemed to work, bolted it down pretty tight. Will try to others as well.

[AiR_GuNNeR]

I typically leave .005" material on the bottom when I do my final profile cut on parts I make. I am able to push the part out and any "flash" that came with it is easily peeled off with a needle nose.