BobWarfield
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- Joined
- Dec 27, 2007
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More rpm!
If you do the SFM calculations, for HSS, I'd run about 60 sfm. For your 1 7/8" diameter material, that'd be 500 rpm.
For the carbide, you'll have to go quite a bit faster. The books would say 3000 rpm (!), and you can't get there with that lathe. No worries, but you can go a lot faster than 150 rpm.
Chatter is a resonance effect. Just changing speed will often get rid of it. FWIW, when I first got a variable speed DC drive on my lathe, I found increasing the rpm helped more often than decreasing. I use mostly carbide, so that may be why.
Feeds and Speeds matter enough, I started using a Machinist's Calculator. First I bought one, then I wound up writing one that I call G-Wizard:
http://www.cnccookbook.com/CCGWizard.html
Cheers,
BW
If you do the SFM calculations, for HSS, I'd run about 60 sfm. For your 1 7/8" diameter material, that'd be 500 rpm.
For the carbide, you'll have to go quite a bit faster. The books would say 3000 rpm (!), and you can't get there with that lathe. No worries, but you can go a lot faster than 150 rpm.
Chatter is a resonance effect. Just changing speed will often get rid of it. FWIW, when I first got a variable speed DC drive on my lathe, I found increasing the rpm helped more often than decreasing. I use mostly carbide, so that may be why.
Feeds and Speeds matter enough, I started using a Machinist's Calculator. First I bought one, then I wound up writing one that I call G-Wizard:
http://www.cnccookbook.com/CCGWizard.html
Cheers,
BW