MWF FEED
6th August 2022, 09:51 AM
First time I have used an indexer. Borrowed a new one that the toolmaker had recently bought from McJing. Listened to his instructions about treating it well, clamping down to a clean table, using Aluminium plates for clamping to keep the paint nice etc.
Borrowed a 5C collet (20mm) off someone else, set it up on my cramped RF30 table, and:
IMG_3103.jpg (https://metalworkforums.com/attachment.php?attachmentid=399375&d=1659736315)
the job reefs around in the collet, chewing the back of the disc I am machining :((
I re-aligned the job, tried to tighten the collet handle as much as I dared (handle is just a casting, so I wasn't going to hammer it), but it still slipped.
Disc is stainless, so I'm gently cutting about .25mm deep at a time with a 5/16" HSS ball nose.
Rod is close to 20mm (19.95 if you believe my cheap mic's),
and there is plenty of crush left in the collet, so I just don't understand why the slippage.
Anyway, the next day, I set it up on his Bridgeport clone with extra clamping on the indexed shaft, and cut it with a 6mm carbide:
IMG_3106.jpg (https://metalworkforums.com/attachment.php?attachmentid=399376&d=1659737780)
(and slot out an extra .9mm on either side to get close to 5/16"). Much more successful.
I have since seen him use the same indexer on a silver steel rod (machining a reamer) without extra clamping, so it doesn't seem to be a problem with the 5C sleeve.
Anyway, lesson for the inexperienced (me)! Use lots of clamps.
Attached Images
https://metalworkforums.com/images/attach/jpg.gif IMG_3106.jpg (https://metalworkforums.com/attachment.php?attachmentid=399376&d=1659737780) (203.6 KB)
https://metalworkforums.com/images/attach/jpg.gif IMG_3103.jpg (https://metalworkforums.com/attachment.php?attachmentid=399375&d=1659736315) (132.7 KB)
Read the full thread at metalworkforums.com... (https://metalworkforums.com/showthread.php?t=208362&goto=newpost)
Borrowed a 5C collet (20mm) off someone else, set it up on my cramped RF30 table, and:
IMG_3103.jpg (https://metalworkforums.com/attachment.php?attachmentid=399375&d=1659736315)
the job reefs around in the collet, chewing the back of the disc I am machining :((
I re-aligned the job, tried to tighten the collet handle as much as I dared (handle is just a casting, so I wasn't going to hammer it), but it still slipped.
Disc is stainless, so I'm gently cutting about .25mm deep at a time with a 5/16" HSS ball nose.
Rod is close to 20mm (19.95 if you believe my cheap mic's),
and there is plenty of crush left in the collet, so I just don't understand why the slippage.
Anyway, the next day, I set it up on his Bridgeport clone with extra clamping on the indexed shaft, and cut it with a 6mm carbide:
IMG_3106.jpg (https://metalworkforums.com/attachment.php?attachmentid=399376&d=1659737780)
(and slot out an extra .9mm on either side to get close to 5/16"). Much more successful.
I have since seen him use the same indexer on a silver steel rod (machining a reamer) without extra clamping, so it doesn't seem to be a problem with the 5C sleeve.
Anyway, lesson for the inexperienced (me)! Use lots of clamps.
Attached Images
https://metalworkforums.com/images/attach/jpg.gif IMG_3106.jpg (https://metalworkforums.com/attachment.php?attachmentid=399376&d=1659737780) (203.6 KB)
https://metalworkforums.com/images/attach/jpg.gif IMG_3103.jpg (https://metalworkforums.com/attachment.php?attachmentid=399375&d=1659736315) (132.7 KB)
Read the full thread at metalworkforums.com... (https://metalworkforums.com/showthread.php?t=208362&goto=newpost)