Has anyone tried knurling on a CNC milling machine

Not I. Not sure that the spindle can apply sufficient force.

Just hold them to swap into the Turret T knurlers discussed in another thread. Knurls wear out, and you will need matched pairs for the knurler.

Enjoy, DoN.

I think that he was talking about putting a knurl pattern of a flat surface by moving it under the knurling tool held in the mill's locked spindle.

I don't think that the mill can apply enough force to do this, however.

As for good *lathe* knurling tools -- my preference is the Aloris sort of like this:

eBay auction # 370517093202

except that instead of having a shank, it fits directly on a BXA toolpost. The knob turns a leadscrew with left-hand thread on one end, and right-hand on the other so the rollers and arms remain centered above and below the workpiece as you adjust the diameter.

Or -- with the turret, I prefer the 'T' style ones like in

eBay auction # 120738214924

except that mine have a 1" shank to fit my turret without an adaptor.

Enjoy, DoN.

Guy Lautard's book _The Machinist's Third Bedside Reader_ has a write up on flat knurling.

Do you want to know how to:

• fit a backplate to a lathe chuck? * use an edgefinder to best advantage, and how to "Pick up" an edge in a hurry? * hold a gib strip for machining? * pull a tee in the wall of a pipe? * get broken taps out of aluminum? ==> * knurl the edge of a rectangular block?

Suppose the axis of the diamond-pattern knurl wheel is parallel to the lathe's x axis. The teeth of the knurl are at some angle to that axis, say 35 degrees. If you orient your caliper at 35 degrees when you measure tooth separation and you measure 0.0344", then along x the tooth distance is 0.0344/sin(35) ~ 0.060", which apparently is what J. A. Harvey in is talking about measuring.

However, in the articles about straight knurls, the pitch used in the calculations is tooth separation measured along the x-axis, and it seems to me that's the relevant pitch for diamond knurling too. For both straight and diamond knurls you can get that number by dividing (pi*D) by the number of teeth, where D is a diameter of the knurl wheel.

I was talking about knurling flat surfaces.

Think about this, the mill has enough force to drill one inch holes.

The servo motor can apply 2.5 ft-lb IIRC, doubled by pulley that gives 5 ft-lb, applied to 2 inch screw diameter it gives 60 lbs, and applied to a 10:1 thread it gies 600 lbs. Gotta be plenty.

I ran a job (a tool) for one of my customers that required a straight knurl in a groove. Using a single coarse roller, I made a holder that was held in a 3/4" collet and knurled the part (tool steel). Worked fine, but required several passes. Did it on a Bridgeport mill, in fact.

I expect you'd have similar success with a diamond tool, although you won't be able to achieve the diamond pattern on a blind piece unless you do it with single rollers, one at a time.

Harold

Try:

Just had this thought:

You can make a very similar surface quickly with a scribe tool on a CNC mill. Just program your pattern. I wouldn't risk harm to your Z ball screw.

Karl

I've never discounted the possibility of bearing damage (brinelling) on the static spindle, either.

Harold