machining copper (turning spirographic finish)

[fat fanny]

Anyone ever turned and copper inlay on nickle overlay on a stainless 1'x6' heating stub? I know it was a mouth full but have been doing about 6 of these a month and while turning the spirographic finish on the last pass with ahigh speed tool 60 degree included angle it tears something fearse. Any input?

 

[rbh]

Re: machinning copper (turning spirographic finish)

Re: machinning copper (turning spirographic finish)

Sounds interesting, post a picture or two so I can see what your talking about.

 

[fat fanny]

Re: machinning copper (turning spirographic finish)

Re: machinning copper (turning spirographic finish)

Can't my company has policies plus machininng and welding copper to inlaied nickle isn't exactly something they want to share I know it sounds hippocriticle when asking the ? I did. What I can say is this is an electrode for melting steel and the copper spirograph is the electrical connecting surface. right now I have been using tool steel ground to a 60 degree included angle tip and my lathe is set to thread and by not using the half nut to ensure the proper engagement point I have to use a ground bar on the stub (clamped) withan indicator to 0 as a strting refference point allong with the readout on on the Xaxis to ensure I track the same tool path, the feed has to remain the same @.039 per rev but the rpm I have been experimenting with I think is the issue @ a finish depth of .030 I doo this in 4 passes two passes of .010 and two @.005 the problem of ripping the copper occurs when I get passed the .020 passes. At 1st I tried it all in one pass which was a dissaster so with all that said 107 rpm has left me with the best results the customer loves it but I always try to make it better which I have for the most part by using more relief on the tool and a constant bath of WD-40 through a unimist sprayer. Any suggestions or tips would be taken with great apprieciation. And oh yea by the way this is not on the O.D dia it's on the face of the stub basically a thread on the face (flat surface)

 

[Cofe]

Re: machinning copper (turning spirographic finish)

Re: machinning copper (turning spirographic finish)

Instead of using WD-40, try using a 50/50 mix of acetone and ATF fluid. You won't believe the difference.

 

[fat fanny]

Re: machinning copper (turning spirographic finish)

Re: machinning copper (turning spirographic finish)

I don't know if there is any acetone on hand at the shop let alone tranny fluid. I would imagine I most definately can use a mixture of tolene and hydraulic fluid. Just curious is this mixture of atf and acetone from profound knowledge? I do have tons of cutting fluid for threading.

 

[dwco5051]

Re: machinning copper (turning spirographic finish)

Re: machinning copper (turning spirographic finish)

I remember in one of my college classes the instructor saying that milk was the cooling/lubricant to use when machining copper. Asked my father about that and he said it was true. When he graduated from college first in his class in mechanical engineering in the midst of the depression the only job he could find was running the tool room and as a tool grinder in a large firm. Years later after he retired and having worked on the Manhattan Project, designing components for nuclear subs and nuke power plants and having worked on space shuttle projects he still said it was one of his most rewarding jobs.