Need Help!- knurling keep double tracking/cnc

[MKMANU]

Hello All Im attempted to knurl on 321 SST

I have a range to finish the OD from 1.579-1.609

160DP diamond knurl convex knurl / straddle holder from accutrac .745 dia rolls L&R hand

Eurotech SLLY elite multi

feeding axial on Z

160 DP should roll .009..

Figure Id start at 1.583 and knurl to 1.590-1.592 RPM at 75 feed at .015
Ive adjusted +-.005 on blank diameter but still double tracking

I have had better luck on a swiss scew machine witha a single bump knurl than I'm having now..

Any tips?

[fizzissist]

The diameters of the knurls are wrong, not the part.

[MKMANU]

the rolls are wrong? Only size that fits the holder I have .75..1.0 rolls for a 1.0 sq shank my machine holds 3/4

[fizzissist]

Ok,
Assuming you're using 2 straight rolls, set at opposite angles for a diamond...

Carbide pins, properly lubed, no more than 50 SFM, and give it a good solid feed rate to get the rolls well engaged within the first revolution. You want to get on, and get off to prevent work hardening and flaking.

I mentioned diameter ... You want to make sure that the part diameter is a correct multiple of the pitch of the knurl.

[djr76]

try increasing feedrate, come in on 'X' then knurl on 'Z'

[MKMANU]

got it, took some adjust on the blank diameter..But after all my aggravation..The DP call out on the drawing is incorrect..should be a 96DP