KeithB
Resident Half Fast Machinist
Had a job machining some 7/8" diameter C182 copper and some A2 tool steel. I used collets to hold the parts. The problem is that the A2 is so hard that it slips in the collet and pushes into the chuck. When it does it scars the material and screws up all the dimensions. What I did was cut the the pieces an inch longer than the finished part. Then I turned one end down for 3/4" to the next closest standard size - the copper was .875 so I cut it down to .813 (13/16"), the A2 was .890" so I used an emergency collet to make a .890" collet and then I turned down the A2 to .875. When I put the turned down end in the collet the shoulder prevented slipping and in fact the thrust just caused the collet to grab tighter.
After turning down the nose and drilling and chamfering a 2mm center hole the tailstock center was used to support the end while the body of the part was turned down. Then the extra length on the end of the piece was cut off, followed by the final step of facing off the flanged end and drilling the end hole. This is the step shown in the video. This was done on our Haas TL-1 lathe using the gang tooling setup.
Turning the main body between centers.
Copper on left, A2 on right. Note the extra material left on some of the copper bars prior to being cut off.
Here is a youtube video of heading off the flanged end and drilling the center hole.
After turning down the nose and drilling and chamfering a 2mm center hole the tailstock center was used to support the end while the body of the part was turned down. Then the extra length on the end of the piece was cut off, followed by the final step of facing off the flanged end and drilling the end hole. This is the step shown in the video. This was done on our Haas TL-1 lathe using the gang tooling setup.
Turning the main body between centers.
Copper on left, A2 on right. Note the extra material left on some of the copper bars prior to being cut off.
Here is a youtube video of heading off the flanged end and drilling the center hole.