what coolant to use when milling copper?(3d design inside)

[HawainPand]

Hi, im about to mill some copper blocks, heres some 3d designs and figures




the block Is 2”x2”x.75” the channels are .65” deep and I will be using a 1/8” carbide tip router bit, but im unsure of what coolant to use, can I use water, and how would I apply the coolant, I read its hell to mill copper, but im doing this to cool my computer, this is my first time, thx a lot!

[HawainPand]

also, can you also recommend me at what speed i should drill at, and any other tips, thx!

[rtucker]

The only copper I have worked with was 510 alloy. It had a very bad habit of 'gumming' up in the tools. We ended up using a oil based coolant, and machining in small steps to make the parts. We seemed to have most of the problems when the material would get hot, we would make a pass (slot cut) and the material would 'grow' and close up the slot by .01-.015. Try cutting it slow, small steps with plenty of coolant.

[HawainPand]

im gonna work with 110, i think its..softer, i dunno, can u recommend me a model or brand of oil based coolant?

whats a slot cut?

i dunno, do u guys think i should use diff bits every so often, maybe to save their life span, lol, do u guys know approx how many bits it would take?

[MobilDave]

Nice heatsink… Have you considered aluminum it is easy to work with and dissipates heat well?

[HawainPand]

yeah, i think i would rather use aluminum, i can get it for one half the price, but its not as good for cooling, its thermal conductivity at around -40C which is around wat my block is gonna be used for will perform a lot better with copper

[rtucker]

I would use Master Chemical's Trim C320, Its sold by quite a few dealers, or you can get it on-line at www.jlindustrial.com. I would start at 65 sfm and .003-.010 per rev for drilling and 125 sfm and .002 per tooth feedrate.

[MobilDave]

If you were to add a lid, gasket and two hose barbs to your design you could make it liquid cooled.

[HawainPand]

yeah, i have a lid, but i don't think im gonna cnc mill that, all i need is two holes lol, thx, yeah, liquid cooling though i would prob make the block much thineer, thx though

um thx for the suggestion but, how would i apply the coolant when i mill?

[rtucker]

Probably the least expensive way would be a "garden sprayer" like they sell at Wal-mart or Lowe's. That way you could fill it with coolant, pump it up and just spray as your cutting.

[HawainPand]

how about a small spray bottle?, so all i need it to spraysome coolant every so often onto the copper block while its milling?

[rtucker]

I would spray the whole time you are machining.