Suggest index toolholder set please

[AllenV]

Excellent! I am glad you checked, because now you know. 6" bench lathes aren't exactly health hazards, but it pays to stay informed. Independent chucks are usually rated for a good bit less RPM than scroll chucks.

Now I understand we are miscommunicating. For clarification of this thread, I am using a 13" swing lathe with a 6" chuck installed.
Still, very glad to have learned that chuck RPM has limits that need to be known.

 

[AllenV]

Your Kennametal SCLCRF 103B is neutral rake, and the CCMT inserts designed for it have a 7° relief angle. So you're good there. I will say that your are really maxing out MRR. I typically run that toolholder and a quality insert at 900-1100 RPM on my PM1340, but often with higher DOC. Yes, I can push it a lot harder but the pucker factor goes way up. And depending on the position of the QCTP relative to the center of the compound point of rotation will have a big impact on rigidity and the tendency at those RPM's for the tool to start hobby-horsing which will lead to insert crack. Chuck limits were my first concern reading your post, but I see you've checked that.

Yes indeed, the exercise of the first chip cutting I posted was precisely to max out MRR. I have no objective reason to run so hard, but wanted to try it. And, as both you and @G-ManBart have pointed out, stuff happens real fast and the risk of crashing with inattention or mis-handling the feed lever is high. Too high for relaxed and careful hobby work. Rest assured the MRR will be dialed back in future.

 

[AllenV]

@pontiac428 , I meant to include you in the previous post as one cautioning prudence in high MRR. My apologies.

 

[AllenV]

As a point of reference, I wouldn't use the Bison numbers as a generic spec because there are a lot of variables.

For example, Precision Matthews uses San Ou chucks for at least some of their machines. As you mentioned, the 6" 3-jaw is listed at 3,600rpm and if you look at a San Ou sold by the importer (which I believe is CME Tools here in Michigan) their picture shows 3,600rpm on the chuck itself. But if you look at their set-tru style 6" chuck it's only 2,500rpm...pretty big difference.

There are others that are the same style (non-adjustable) where they don't appear remotely close to what Bison lists. My 8" 3-jaw San Ou is marked with a max of 2,000rpm, so a full 1,000 lower than Bison.

I actually was looking at a 10" chuck for my 14" Logan recently and several I saw weren't rated for the 2,000 rpm the machine capable of...almost forgot to check that!

I trolled around this morning looking at "value oriented" self-centering three-jaw chucks with 6" diameter. The lowest common denominator looks to be 2500 RPM max rated spin. Pretty easy to get into a higher max RPM for a modest price bump.