Metal Lathe question

[Perry Holbrook]

I am working on several designs for a corporate gift commission. One of the possibilities would need me to taper a copper rod that would go from 5/8" down to about 1/8" over 8" of length.

I suppose I could forge the rod into shape, but I would need about 150 of them and they need to be pretty much the same shape.

I think I could use a smallish metal lathe to rough out the taper. The final piece needs to have a hand forged look so either way there will be some hammer work. The lathe would just remove some metal rather than having to move the metal by forging.

I know I'll need a center support and will need to have some waste at each end.

My question is: Can I taper this rod on a metal lathe without much trouble? My plan would be to buy one of the small combo lathe/mill to do the job, something like the Smithy or Grizzly.

Thanks, Perry

[Bruce Page]

Perry, that would be a little tricky even for an experienced machinist. Copper is one of my least favorite materials to machine, it is difficult to get a decent chip, it is gummy and will load up on the tool bit. The best way to machine it is at high speed with a heavy flood of coolant. 150 of em? Ferget it, take it to a job shop with a bar fed CNC lathe.

Probably not what you wanted to hear…

[Frank Chaffee]

Perry,
Perhaps the lengths could be heated and drawn.

Member Harry Strasil may be able to help.

Frank

[Brian Hale]

I'm with Bruce, copper can be a real pain to machine. In addition to being gummy and loading up cutters, it's tuff on cutting tools, even carbide. Always seems that as soon as you get the speed/feed just right, the tool begins to dull and needs replacement.

Find a shop to do it for you.

Brian :)

[Wes Bischel]

Perry,
I'm not sure whether this would be consistant with your design, but could you use a tube instead of rod? If so, the part could be spun down from a tube (versus sheet). Copper is actually a great material for spinning versus machining.

Just a thought.

Wes

[Perry Holbrook]

Doesn't look like this will be my justification for a new tool. There are several job shops around here that could handle the CNC approach.

Maybe I should look closer to my other design that uses flat stock.

Perry

[Dan Oelke]

Disclaimer - I'm not a metal working person -

Could a tube or a sheet be cut to size be wrapped around a steel form and hammered into shape? Just an idea.

[Randy Meijer]

What about making the rod out of a material that is more machineable than copper and have it copper plated?

[Perry Holbrook]

Thanks for the alternate ideas. The commission is for a small desk top sculpture to be given as a corporate gift, about 75 of them. They want it to relate to "partnership". I'm not much of an abstract artist, but see this as a good challenge. I don't think anything less than solid stock will do the trick for this one.

My second design involves either laser, water jet, or plasma cutting and then hand forging flat stock. I'll probably put together a prototype of that one.

Thanks again, Perry