Knurling, I Know Nothing About Knurling.

[754]

There was a maker of cut knurling tools here in BC. I forget the name of it, but it was made by Johnie Fox that owned Sharp-Rite grinding on Schoolhouse Rd, Coquitlam. Anyway i believe It used a single cut wheel at a 45 ? Degree angle ..... you would make a pass one way , then pull a pin and flip the wheel , then insert pin....and cut back to the start,, with a finished knurl. I think in the pictures I saw they had sharp diamond Knurls about .75 to 1. Inch long.
Huge Sharp nice knurls.

[JRouche]

What 'impurities'?

I cant put words in his mouth but I think the shavings from a cut VS form knurl is the debris. JR

[DR]

All my knurling is done with a scissor type tools made by B&S. Perfect knurls every part after the first setup piece to determine depth. Production runs are done on a CNC lathe.. I tried a cut knurler a few times, a pita to setup. Throw your old side pressure knurling tools away.

Very fast infeed to part center, no coolant, no worry about blank diameter, fast longitudinal feed to minimize running over the already knurled area. For parts with no longitudinal feed, fast onto the part and fast off. Try to do the knurl in as few revolutions of the part as possible (it should only require one revolution of the part).

The no coolant business came from the knurl making company I bought from. They recommended it and I've seen no advantage with coolant. I do program the CNC a short spurt of coolant on the knurl axles for lubrication prior to part contact otherwise the carbide axles and wheels can get fairly hot on long runs.

Do not knurl aluminum if the parts will be color anodized. Aluminum makes fine flecks of swarth even with forming knurls, those fine flecks get pressed into the knurl surface. During anodizing some of those flecks can break loose leaving an obvious uncolored spot in your part, it shows up especially bad with black color. Old timers in the anodizing business tell me the used to dip black parts in India ink to cover the spots.

After my first disaster with speckled black diamond knurled aluminum knobs I started looking around. It's surprising how few diamond knurled black knobs you'll find. Most knobs are made from bar stock with a straight knurl made in the extrusion process.

Delrin knurls very well. For some unknown reason I expected it wouldn't.

On a few rare occasions I've gotten doofus customer prints with a close tolerance like +/-.005" on knurl diameters. Hard to accomplish, we'd get it close, then take a skim turning pass over knurl to size.