Knurling on my 13”

MyLilMule

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The steady rest I am rebuilding for my 13” South Bend had these hideous plastic things for the three lock screws. I made new ones today. And while I was at it, made a knob for the door to the headstock cone pulley. Mine was missing. These were my first projects using the the knurling tool I bought from Shars Tool.

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You've got a problem - somewhere. The only knurl that I can see even close to a profile view is the far right one in the second picture. One wheel is cutting way deeper than the other. You want both to be cutting the same. Make sure that the tool centerline is on the centerline of your lathe's axis. That way, both wheels will more or less cut identically.

What you have done is completely serviceable, but for better looking knurls, get your tool set up correctly.
 
You've got a problem - somewhere. The only knurl that I can see even close to a profile view is the far right one in the second picture. One wheel is cutting way deeper than the other. You want both to be cutting the same. Make sure that the tool centerline is on the centerline of your lathe's axis. That way, both wheels will more or less cut identically.

What you have done is completely serviceable, but for better looking knurls, get your tool set up correctly.
You'll notice I corrected that issue with the knob for the cone pulley door. The tool height wasn't quite right on the first three.
 
Nice work! Functional and you learned something along the way, what else is there?
My I ask exactly which tool you bought? I'm looking for something better than the "push in with the cross slide" style. Waiting for a good deal on a "pinch" style but hate to spend the money on a guess without more information.
 
Very nice. I've always struggled with knurling. The pattern never seems to repeat itself, always wanting to 'double up'. Someone told me there are actually formulas and certain dies for different diameters?

Anyway, yours turned out very nice. Good job.
 
Nice work! Functional and you learned something along the way, what else is there?
My I ask exactly which tool you bought? I'm looking for something better than the "push in with the cross slide" style. Waiting for a good deal on a "pinch" style but hate to spend the money on a guess without more information.
It's just the push in style. Like you, I'd like a scissor or clamp style, but out of my budget range right now.
 
As a friend explained to me, to be a perfect match the circumference of the work must be an even multiple of the pitch of the knurl teeth. If the work is a different size, the next trip around will cause the teeth to hit a different spot.
BUT as the knurl cuts in, it doesn't have to go very far to find that proper circumference and then it starts tracking back in the same spot each revolution. From there on out, it continues to just deform the work into the gullets of the teeth until you get a nice diamond point.
I watched a video where a guy (wish I could remember who) tried all kinds of combinations of work sizes and speeds and feeds and his best results were with putting a fair amount of pressure on the knurls before ever turning the work. But he could correct bad knurls just by increasing tool pressure. This kind of confirmed what my friend explained.

But I am reluctant to put excessive pressure on my cross feed, simply because it is a small lathe and I can't afford a replacement. Thus my desire for a scissors type tool. I might have to try and make one. I think I need a mill.....
 
Eagle Rock K144
One of our vendors has a kit, D. Gray
 
There are 2 schools of thought, those who feed in until it tracks properly & those who calculate diameters (for circular pitch wheels). Most us hobbyists knurl for functionality & while feeding in until a proper looking formed knurl works for most, it only works on softer metals like aluminum, brass, mild steel, etc.

If you're knurling harder alloys, SS, Ti, etc, materials that are harder to displace and/or work hardens easily, you're better off calculating unless you don't care about double tracking. Feeding in arbitrarily also won't work for cut knurlers.

If you're using diametral pitch wheels then those are meant to work with fractional size diameters (32nds, 64ths), no calculations needed (well minimal).

Me I'm just a hobbyist but I knurl for cosmetics & functionality. For me double track knurling annoys the hell out of me, I'll scrap the part if it happens to me.

LMS has a simple calculator for calculating diameters for knurls. There are other formulas but the LMS calculator works fine for me. My lil brother added it to a simple app for my phone for quick & easy use.
 

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