Knurling

[dinnese]

Looking for Feeds and Speeds on Knurling. The knurl (single roller) is a 40 TPI and I'm knurling a .172 dia. on Titanium. Never really knurled before so any information would be helpful. Thanks

[SirDenisNayland]

I don't have any experience knurling titanium, but if this is your first time knurling you're in for a fun adventure.

Base starting reccomendations for feeds and speeds are around 100sfm with .005-.01 feed for bump knurling.

Quite honestly there are no givens when it comes to knurling I've found, you have to pick a starting point and work from there with what you have. I could be running an identical set up as you, but my knurl pin is slightly more worn and allows the knurl to spin more freely resulting in different speeds and feeds.

Basically though your main concern first and foremost is that the knurl going down to a proper depth and tracking correctly, once you have that baseline then you can tweak things to perfect the knurl.

Best advice I can give is to pick a speed, find your desired depth and play with your feed. Sometimes you really need to jack the feed so the knurl bites and tracks, but the higher the feed the more deflection you'll have so you'll find yourself offsetting the knurl lower. Also most people will use a dwell allowing one to two full revolutions at depth, depending how long the dwell is you may find yourself offseting up again..

There are a lot of variables to play with, try to pick a speed and work from there with your depth, feed and dwell time. Modify one at a time to see your results. You may slow down the feed and decrease your dwell and find the knurl looks the same as it did with a faster feed and longer dwell..

Let's just say I've torn hairs out trying to get knurls right in the past. The form-roll catalogue has some base starting points and calculations you can do to get your starting values, from there its up to you to figure it out and make it work. I've spent hours before getting a knurl dialed perfect, only to set the same job up a few months later and not have the knurl work at all ending in having to re-figure the whole dang thing out again.

Best of luck to you and hopefully you'll figure it out in a nice timely manner

Cheers.

[dinnese]

I did forget to mention that I am form knurling (pattern is actually right in the knurl itself) and pressing the knurl right into the material on a Star SR20J in Tool location T600.

[hacdlux]

straight or diamond knurl

are you trying to axial feed it

i run production knurls every couple weeks

program for a 5/8 diamond knurl using a straddle knurl

N60(KNURL)
M13S500G00Z-.200T0404
X.0Y-.625
G99G1Y-.615Z.04F.02
Z0.550F.01

for that small you might be better off with a straddle knurl

im too tired to right up my full explanayion riight now, tommorow














X0.705
G28U0
T0

[hacdlux]

http://www.genswiss.com/knurlingtips.pdf

[micky316]

I knurl 1/4" diameter titanium often and the best way by far is to use a cut knurling system ,if you can knurl from the end you wont get better than the 3 wheel "quick" knurls if not the two wheel "quick" knurl from the side is also good but not as good

[gizmo_454]

I am thinking Micky316 may have a good idea. Given the work-hardening properties of Ti, I don't think I would be trying to "roll-form" the knurls on it. Least of all with a bump knurl. A straddle knurl would be far easier on the machine and you don't have to worry as much about deflection due to the equal pressure on both sides of the part.

In any case, based on what I have read about "cut knurling" it may be the best option for what you are doing.

Here's hoping you get it going in a timely manner! As SirDenisNayland said, anybody that has knurled even an easy material, has far less hair when the job is done than when they started!

Mike