Cut-off tool

I changed to carbide insert, Manchester Separator system. MAN WHAT A DIFFERENCE. Don't know why I ever fiddled with HSS. I bought a bunch of expendable parts because of all the breakage I had with HSS, never used any of it (so far)

Karl

"Karl Townsend" wrote in message news:6x5xg.2368$ snipped-for-privacy@newsread2.news.pas.earthlink.net...

I will second that. Night and day difference!

Ken..

Parting tool strategies are different between small lathes and large lathes. If you're running a 20" American Pacemaker, you can use anything. If you're running a 9" South Bend, it can get real tricky. I finally gave up on any compound-mounted tool and sold off my carbide insertable tooling, because I found something that works much better for me - a rear-mounted toolpost holding an Armstrong cutoff toolholder mounted upside down. Of course, on a regular SB cross-slide, there's no real way to mount a rear toolpost so the first thing is to mount a proper cross-slide table.

I got the T-slot cross-slide table & rear toolpost kits from Metal Lathe Associates and have found them to be really high quality and very useful.

Beyond that, I suggest reading teenut's archived postings and also if you can get your hands on a copy of "The Model Engineer's Workshop Manual" by George Thomas, it has a great section on parting tools including how to grind them, how to make a rear toolpost, and gorgeous pictures. It's a British book which focusses on Myford lathes, but very helpful anyway. I don't like his rear toolpost design as well as the MLA one, though.

GWE

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I just completed a modification to my 1976 "JET" engine lathe, 10 X 24. I was using a sheet metal stand that was modified from the 12 X 32 HF sells (cut down the length of the sheet metal web between the 2 stands). Damn thing would dance and walk on the floor with just too slightly heavy of a cutoff feed. I bought a 10 X 40 inch by 2.25 inch thick hot rolled plate, mounted it up on the Index #2 BP copy, and proceeded to use the radial head movement and machine both sides to good enough. Machined tapped the six bolt down locations from both sides, inserted this in between the sheet metal stand lathe and original chip pan, torqued all the bolts (12), leveled it using the sheet metal stand feet. This even leveled easier. I would suspect that the ways were twisting back and forth as it used to take a lot of futsin to get it level. I think it took me 5 minutes this time.

I installed a 8 inch 3 jaw (large but useful on this small turning lathe, a Bison with a custom threaded backplate), chucked a 4 inch hot rolled round chunk, set up a 5/32 parting tool, and cut. This tool was mounted in a "A" Phase II quick change, using the cut off tool attachment. What a difference in rigidity. Still some oscillation that looks like the cantilevered chuck mounting plate arrangement, is "ringing.

This was worth the hours of using too small a vertical mill to attempt to make the two surfaces of the 2.25 inch plate parallel to .002. I'm guessing that's the best I did.

That's my attempt at improving cutoff operations.

SteveK

Ken Davey wrote:

"stevek" wrote in news: snipped-for-privacy@s13g2000cwa.googlegroups.com:

If you will get you some 4"x 4" x 3/8" wall square tubing to make your legs from, and some 3/8" plate for gussets, it will get better yet again.