Search found 91 matches

by rexcsmith
Sun Oct 16, 2016 4:22 pm
Forum: General Discussion
Topic: Filleting on a Lathe
Replies: 15
Views: 3979

Re: Filleting on a Lathe

Harold, do I read you right? No rake? That would be a lot easier than what I've been trying to do.
by rexcsmith
Sun Oct 16, 2016 2:47 pm
Forum: General Discussion
Topic: Filleting on a Lathe
Replies: 15
Views: 3979

Re: Filleting on a Lathe

More info...

The fillet is concave, so the tool needs to be convex.
Fillet radius .125"
Large diameter is 3/4"
Small diameter is 5/8"
Length of small diameter is about 6" between the wheels
3 jaw chuck with live center
4140 steel
by rexcsmith
Sun Oct 16, 2016 10:26 am
Forum: General Discussion
Topic: Filleting on a Lathe
Replies: 15
Views: 3979

Filleting on a Lathe

I'm back with my next question. I'm making axles for my steam loco. The plans call for the axles to be necked down (reduced diameter) between the ends (merely a cosmetic touch). Each end of the necked down area has a .125" fillet. I've tried making a filleting tool out of a 1/4" HSS blank, but it do...
by rexcsmith
Mon Oct 10, 2016 2:23 pm
Forum: General Discussion
Topic: Don't want that taper
Replies: 48
Views: 7306

Re: Don't want that taper

The 4140 dowel is a 3/4" diameter piece of 4140 steel. This time, it's a very short piece; no long tail flopping around. The run-out is visibly perceptible 2" from the collet when running the lathe; not so with the 3/4" end mill. I get your point about the 4140 piece perhaps not being round. I'll ha...
by rexcsmith
Mon Oct 10, 2016 12:54 pm
Forum: General Discussion
Topic: Don't want that taper
Replies: 48
Views: 7306

Re: Don't want that taper

It also doesn't seem plausible that there would be so much difference in runout between testing with an end mill, and testing with a 4140 rod right at the collet.??
by rexcsmith
Mon Oct 10, 2016 12:52 pm
Forum: General Discussion
Topic: Don't want that taper
Replies: 48
Views: 7306

Re: Don't want that taper

OK, I ran the indicator on the closer taper. Amazingly little movement; indiscernible runout. I then put a 3/4" end mill into the collet. It gave me about .0006" runout near the collet. Not great, but useable for most of the stuff I do. Then I put in a 4140 dowel. .002 - .003 at the collet, and much...
by rexcsmith
Sun Oct 09, 2016 11:04 pm
Forum: General Discussion
Topic: Don't want that taper
Replies: 48
Views: 7306

Re: Don't want that taper

I just put that Lyndex collet back in and put a short piece of 3/4" stock in it. It fit in very tightly; no slop. There's a couple thou of runout right at the mouth of the collet. I looked at the runout at the outside diameter of the collet; less than a 10th. That collet seems to be no good. Problem...
by rexcsmith
Sun Oct 09, 2016 8:10 am
Forum: General Discussion
Topic: Don't want that taper
Replies: 48
Views: 7306

Re: Don't want that taper

Great feedback. Given all you've said, I suspect the collets are OK; I just need to be more careful how I'm using them. The lathe is working up to and beyond my expectations using the chuck (actually, it's a 3 jaw; I misspoke). I'm working to within a 10th according to my micrometer. Not a lot of fi...
by rexcsmith
Sat Oct 08, 2016 6:19 pm
Forum: General Discussion
Topic: Don't want that taper
Replies: 48
Views: 7306

Re: Don't want that taper

Good point on a long work piece whipping behind the collet. That could be a clue. I'll check it out using a short piece in the collet. thanks
by rexcsmith
Sat Oct 08, 2016 3:07 pm
Forum: General Discussion
Topic: Don't want that taper
Replies: 48
Views: 7306

Re: Don't want that taper

Going forth with the project using the 4 jaw chuck. I'm getting within a 10th now, even without using a live center (short stickout).
I've learned a lot about my lathe and tooling because of this problem. Thanks for all your help!
by rexcsmith
Sat Oct 08, 2016 11:35 am
Forum: General Discussion
Topic: Don't want that taper
Replies: 48
Views: 7306

Re: Don't want that taper

Problem solved (kind of). I put my Bison 8" 3 Jaw chuck on the lathe and tried again. The first thing I noticed was that I was cutting strings instead of small chips. Then when measuring, I'm within a 10th. Now I can move on with my project. I'm bummed about the 5C stuff not working though. Those ar...
by rexcsmith
Sat Oct 08, 2016 11:14 am
Forum: General Discussion
Topic: Don't want that taper
Replies: 48
Views: 7306

Re: Don't want that taper

Here is a pic of my setup. As you can see, I'm turning about an inch in length. After the turn, the right end of the cut is 2.5 thou greater in diameter than the left end. I used a proper center drill to get the live center seated. I did find that there was some rubbing on the tool so I reground it,...