Cutting copper sheet

[dubliner]

Before you scold me, Yes I have searched, but there isnt too much info on it. I'm going to be cutting .030 copper sheet in about 5x8 inch parts ( leaves ) that client will weld/solder to a frame. I'm thinking up o flute if vacuum holds as I got a great edge in Al with that. So What say you? feeds/speeds/bit type? Thanks in advance. Dubliner

[r_jones]

Neville,
Funny you should ask as I am looking for the same info for a possible upcoming project. I too would anything anyone is willing to share:)

Ron

[shoeshine]

Hey Dubliner,

I have actually had more luck with copper using machining endmills that are intended for metal than any of the "router" bits I've tried. I have a local supplier that mostly deals with machine shops. apparently the geometry is a little different for non-ferrous materials. they sell Basset. I also bought a relatively cheap set of TiN coated endmills from harbor freigh that work well. For detail work I use stub mills from precisebits.com.

As far as speed/feed I take it very slowly, 10k rpm, about .3 IPS

this is simply trial and error though so if has a better way of calculating, I'd love to hear.

The biggest problem I have found with copper is that it deforms so easily. impossible to leave an onion skin as the material will bulge out under the bit. so I either use tabs/screws (cut out with a jewlers saw), or for small parts, a trick where I glue the copper to an aluminum tooling plate with super glue then free it afterword with acetone

Chris

[magic]

I've used end mills to cut 16 gage copper and brass. I had fine detail and had to to slow the speed to .3 ips

Another trick is to vary the depth of cut so the bit dosen't wear at the same heighth (and get dull)

I sandwiched the sheet between two pieces of thin ply and placed screws (with dogs) in places that were already cut to A hold it down. Lots of starting and stopping the file.

[Mike Windsor]

I've cut lots of .062 brass sheet with 1/4" and 1/8" router bits and end mills . I hold it to a spoil board with double sided carpet tape

[shoeshine]

I would agree on brass,

I would also note that I have had more issues with copper than brass due to the deformation issue. copper seems softer and tends to warp if it is not cutting well.

Please note this is just ancedotal via my limited trials.

[knight_toolworks]

last time I cut it it was these small spirals that came to a point. had a hell of a time holding it in place. this last time I epoxied it to some scrap wood and it cut great. hit it with a propane torch and they popped right off nice and clean.

[shoeshine]

good idea Steve,

I'll have to try that on the next thin metal piece I do.

Thanks

[knight_toolworks]

I found heat could loosen double sided tape. but the epoxy worked great. these peices woere only 1.5" overall and came to a thin sharp point. the epoxy weorked great and it was easy to remove. super glue would work the same but it would stink far more.

[robtown]

I cut some .090 copper nameplates once. I just used standard end mill tooling, I needed a beveled edge so I bought a chnfered endmill from MSC. I just used carpet tape and stuck the copper down to a pc. of Melamine (and screwed the Melamine down to the spoilboard).

Went slow and used a fair amount of coolant.

It turned out good, but the shavings were like little daggers, so be careful or you'll end up with copper splinters.

[harold_weber]

You will find a huge variation of "machinability" in copper depending upon the alloy you choose. I recall years ago trying to get 99.95% pure copper machined, and a VERY skilled machinist had a terrible time getting a good surface finish on it. According to McMaster, only ONE of the copper alloys they offer has "good" "machinability".

[dubliner]

"Little Daggers" I like that imagery :-). This is a 3 ft x 10 ft sheet. I dont know if I could afford that much DS tape. I'm hoping my 9-15 and some screws will do the trick. Otherwise I may cut it into smaller sheets and concentrate one zone. Well thanks for all the tips guys. I appreciate it & I will pic & post my findings. Dubliner

[robtown]

That sheet of copper will cost much more than a roll or two of carpet tape.

R