[jinu117]

Basically what I am trying to do is to put 7mm deep groove in copper stock (electrograde) of 1.5".
The machine I am using is the 7x10 Parting tool is regular T-slot 1/2" from littlemachine shop. 1/16".
I could do the job over... VERY long period of time and numerous stops (it seems like the controller just stops the motor if it detects too hard of cut), and high screeching sound, etc.
Basically the feeling I get is that either I am using wrong tool for this job on copper or doing something seriously wrong. (as I have no problem parting 1.5" aluminum... using same setup)
Is there some specific tools or tips I can get from you guys on being able to do this job without too much f*** word coming out of my mouth every 30 seconds or so?

[RICHARD ZASTROW]

jinu117, Copper tends to build up at the cutting edge. The closer to pure copper, the worse it gets. Make sure your tool is at the correct height to avoid "grabbing". Don't laugh but I've had good luck spraying frying pan goo "PAM" on the tool to prevent the build-up.

[keebler303]

I generally use kerosene to keep stuff from sticking to the cutter when machining dry. Its in a small wd-40 spray bottle. You will have more trouble as it heats up, are you using coolant?

Matt

[blksmith]

you might try a negitive rake tool, it will help stop the tool from grabbing

[handlewanker]

Hi jinu, tool must be SHARP, with a top rake of about 20 degrees.
Front clearance not more than 3 degrees.
If you've been cutting steel with it then it will rub and work harden the cutting slot.
This causes you to increase the inward force and so the tool digs in. Speed must be as fast as you would use for alluminium. (400rpm for 1" diam.)
The copper will also have a tendancy to weld itself to the sides of the tool, as the tool you are using does not have side clearance behind the cutting edge.
A 1/16" wide tool going in 7mm could have the sides relieved a few thou' to stop it rubbing. Use plenty of coolant.
Last but not least, tool MUST be square to the job to stop sides rubbing as you get into the cut.
Oh yes one more, make damm sure the tool is on centre height. If you are .002" above centre it will rub and dig in.
Bin turnin' fur furty yars and copper is still a B###@@@STD to work with.
One very handy tip for drilling copper and the bronzes is to grind the drill point a little bit off centre. This will make the drill cut oversize and so will not bind up in the hole.
Don't drill too deep at a time, or the chips will weld to the drill. The job also has a tendancy to get hot at the bottom of the hole and it will expand, and then contract as the coolant reaches it, and so grab the drill.
One of the worst materials for this is alluminium bronze which will work harden even if you just look at it.
Ian.