First time knurling

[Janderso]

I had no idea what I was doing, it came out OK.
I'm making two locking nuts for a sheet metal brake I've been working on, and off.
This was fun.
I need a scissor type knurling accessory though, I don't like this bump style.
Threads are 1/2 X 13

 

[Dudemanrod]

That came it great Jeff. When I get going I need to make a big knurled round nut for the back cover of the lathe. I have a three way knurling tool the fits in the quick change but have to get a 3/4 tool holder.

 

[Janderso]

Thanks Mark.

 

[brino]

Crisp and clean. Well done!
-brino

 

[MrWhoopee]

Not being critical, but one of the wheels has double-cut. Note that there are two lines on one angle to one, much clearer, on the other. It happens all the time, at least for me. It doesn't affect the function nor the appearance to anyone but a nitpicker. Harry would make us go back and try again. The cure is supposed to be more pressure when first engaging, forcing the knurling roll to slip into the existing groove as it comes around on the first rotation. Cutting oil helps sometimes. Once established, the pattern will continue. My toolpost just doesn't seem to be able to hold the pressure and rotates. In addition, this puts a lot of pressure on the cross-feed nut. This is exactly why bump knurling tools are unpopular.

 

[Janderso]

I don't know the terminology Mr. Whoopee. I do see how maybe one of the rollers has a more dominant pattern. I say this because there is only one diagonal root, if you will.
Maybe that is what you are calling, double cut?
You are right though, looks and function are within my standards, especially for my first attempt.
I do not like putting that much force on the spindle, tool post, cross slide or compound.
This is 12L14 too. Very soft.

 

[darkzero]

It's called double tracking. There's 2 schools of thoughts on knurling.

One is to calculate the work piece diameter so that the amount of teeth on your knurling wheels divide evenly into the circumference of the part. If you use diametral pitch wheels they should divide evenly in nominal sizes. The stuff that I knurl is rarely ever nominal sizes so I use circular pitch wheels & calculate.

Other people say (& have done) that you don't need to calculate knurling diameters, just feed the knurling tool so that it displaces enough material & eventually tracks properly. This does work on softer materials but doesn't always work on harder materials in my experience. With this method you don't have control over the crests of the knurl if you have to feed in too deep, the crests will get rolled over & won't look crisp.

I am one of those who almost always calculates knurling diameter. Many times I knurl for cosmetic purposes over functionality. Knurling can be easy & a PITA for even the most experienced machinists. I'm no pro but I've got pretty familar with my knurling tool.

 

[MrWhoopee]

Yes, if you get out your magnifiers and look closely you'll see it. I see it on tools in the store too. The 12L14 should make it easier as you can get that full depth groove on the first rotation. It is hard to bring yourself to crank it in that hard that quickly. You tend to want to go in gently. The spindle can take it, the toolpost can take it, the cross-slide nut can probably take it. It's much easier to do when it's not your lathe.

 

[GoceKU]

Knurling is hard on machines if you don't use clamp type knurler, i personally do multiple passes with auto feed with light pressure till i get the results i like. I would recommend using a clamp type tool on a smaller lathe, my lathe has no trouble reaching the full depth of the knurling wheels.

 

[Janderso]

Knurling is hard on machines if you don't use clamp type knurler, i personally do multiple passes with auto feed with light pressure till i get the results i like. I would recommend using a clamp type tool on a smaller lathe, my lathe has no trouble reaching the full depth of the knurling wheels.

Thinking about the spindle, if you place a 45 lb. part on the chuck, look at the downward pressure involved at rest.
I have a pretty robust lathe. Clausing Colchester 15X50.