Some new things learned cutting brass.

[knight_toolworks]

I needed to cut these washers with a slot in some 1/16" brass sheet. I double sided tape to hold it in place till the screw holes were drilled and keep the pieces from flying around when they were cut out. well that was the first thing to learn the heat melted the adhesive on the tape and made it hard to remove. second was getting the 1/8" endmill to plunge through the brass. I zero'd at the table surface and used ramping to cut the screw holes but the bit would only cut about 1/2 the way through. I had to lower the bit a bit lower then the table surface and zero it to get it to plunge through the sheet. this happened with every cut a slight hesitation before the bit plunged through. Do lots of test cuts. I was making the washers with a 1/2" long 1/4" wide slot and they were .75 diameter. well a climb cut got the outside the closest at .76 but the inside was too small. a regular cut got the inside pretty close (it was fine) and the outside at .71 so it took 5 or six tries to find the right offset to get the right cut.
since I lowered the bit that much it was cutting through the tape and I had to grab the pieces or they would get caught on the bit.

[ernie_balch]

It sounds like the machine is not rigid enough to cut the brass. There must be some spring in the Z-axis that lets tool have 1/32" of give before it starts cutting the brass.

ernie

[knight_toolworks]

yes or the carriage is lifting a bit. I will have to closely next I cut it.