knurling woes

Are you tightening _then_ switching on, or tightening gradually as you run the lathe in back gears? (I assume you have the knurling wheels wet with oil...)

-- Jeff R.

Sounds like the bottom of the toolpost and the top of the compound are NOT flat. I would check and repair that problem, then when you tighten up the mounting bolt/nut, it should stay put. If you continue to have problems after the flatness issue is resolved, maybe a very thin coating of valve grinding compound on the bottom of the toolpost would help. Ken.

FWIW,

I had all sorts of trouble with this type knurl tool. Especially with part deflection on smaller diameters. I switched to the scissor type knurling tool and have had much better success.

Karl

Try a thin sheet of gasket paper between the metal surfaces. Just cut one out of a stationary folder, corn flake packet or similar and bolt back down. Will often stop a post or mount from turning under pressure.

Hope this helps, Peter

a piece of paper. try the yellow legal pad type. Give it a shot, you may be surprised on how well it holds. Wipe it clean of oil before putting the paper down.

Gunner

"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.

Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner

And make sure that the "T-slot" of the compound is set parallel to the work, that is, swung from the "normal" 29.5 degrees position and set to "0" degrees, and further..... that the knurling tool holder is also perpendicular. Keeps all the "pressure" shoving directly back, and against the lead screw so it can't move.

It is not necessary to do a "single pass" either, although there are some who won't believe that. Trying to cut too deep on light-weight machines will cause a lot of side pressure at the knurl, which will attempt to "swing" the tool-holder.

In the past I have tried to do a "step" action, whereby you run the knurl in to a specific depth, back it out, move it sideways to run back in with a slight overlap each time. Works OK if you don't want beauty.

Take care. Good luck.

Brian Lawson, Bothwell, Ontario.

I wonder if you are either pushing way to damn hard, or if the toolpost t-nut or stud is not allowing it to tighten properly. IE the top hat part of the t-nut is touching the bottom of the toolpost, it can't really tighten on the compound a bxa has like a 7/8 nut, which is a foot long wrench, if you are leaning on that to something like 80 ft lbs, you had better not be able to spin the toolpost.

I have a BXA sized Phase II (Series 200) which occasionally slips under heavy load -- or at least did until I put paper under it.

However, when I do knurling, I don't use the tool which came with the set, but instead use a scissors style knurling tool, which applys the knurling rolls to the top and bottom of the workpiece, with no significant force applied to the toolpost itself. The one which I have was one of several models made by Eagle Rock INC -- though when I got it from MSC, they did not say who made it in the flyer.

There are two styles. One has a pair of pivoted arms which are connected by a screw and nut which is used to adjust the force between them. It will fit in a normal toolholder with at least a 1/2" slot (so the BXA holders are quite adequate).

However, more recently, I have been using one which was made by Aloris, which is a BXA sized holder with a vertical dovetail on the front, with two traveling arms carrying the knurls. They are connected by a screw which is left-hand thread on one end and right-hand thread on the other end, with a knurled knob. It, also, applies the knurling rollers to the top and bottom of the workpiece, so it transfers

This one, once it is set to the right height, works very well, and adjusts to other sizes easily. (There are even holes in the big knurled knob for tommy bars, if you really need to crank down.)

I forget what the actual price is new from MSC, but I got it from eBay for significantly less -- under $100.00 IIRC, and have never regretted it.

Enjoy, DoN.

I checked this and it was ok, but, I found that the surface of the compound was quite oily. I'll clean this off with lacquer thinner. This should make a difference. Thanks, John