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How to Turn 101 Copper?
- Thread starter ACHiPo
- Start date
- Joined
- Dec 20, 2012
- Messages
- 9,422
Dunno how to answer this one. The only copper I have turned is the C101 stuff and it is supplied as a nearly pure copper bar that was extruded. Copper is one of the softest metals in common use so its pretty soft.
- Joined
- Sep 29, 2014
- Messages
- 2,102
As far as turning there are inserts made specifically for copper , if you have many parts to make this would be the way to go.
When only a handful of parts are required I have had excellent performance with aluminum specific inserts turning large copper electrical conductors. I would not do so without flood coolant however.
If only making one part go slow and use sharp positive rake tooling, the finish doesn't appear to improve with speed in this material, for drilling and tapping lard oil works a charm but is nasty in many ways.
For holding I would pocket soft jaws 1/8' deep and face one side then turn as much of the OD as possible, flip then face to length and turn the rest of the OD as needed.
Like so, one face and most of the OD finished, then flipped and faced to length and the rest of the OD turned. 42 parts in 304 SS, the order was for 40 but I made 2 extra because they get a good deal of mill work done to them afterwards including some 4-40 tapped holes, if a tap is broken in one I would have to set up the lathe again to make 1 more so I planned ahead.
When only a handful of parts are required I have had excellent performance with aluminum specific inserts turning large copper electrical conductors. I would not do so without flood coolant however.
If only making one part go slow and use sharp positive rake tooling, the finish doesn't appear to improve with speed in this material, for drilling and tapping lard oil works a charm but is nasty in many ways.
For holding I would pocket soft jaws 1/8' deep and face one side then turn as much of the OD as possible, flip then face to length and turn the rest of the OD as needed.
Like so, one face and most of the OD finished, then flipped and faced to length and the rest of the OD turned. 42 parts in 304 SS, the order was for 40 but I made 2 extra because they get a good deal of mill work done to them afterwards including some 4-40 tapped holes, if a tap is broken in one I would have to set up the lathe again to make 1 more so I planned ahead.
Since my work has been in sheet and bar stock I wasn't sure how the temper would affect turning or other machine work. I know drilling (I use 118°) and tapping is all about sharp tools and lubricant. In regards to hardness, my experience is working copper is the reverse of steel and I guess the easiest example to explain would be when I tin my soldering irons. If I heat them up and allow them to cool they are harder than when dipping them in the sal ammoniac water solution to keep a good tin. The hardness I mentioned is achieved through cold working or pressure applied during the rolling/drawing process. I usually use 1/4 -1/2 hard for most products.
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