# First time knurling



## Janderso (Nov 11, 2019)

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


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## Dudemanrod (Nov 11, 2019)

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.


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## Janderso (Nov 11, 2019)

Thanks Mark.


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## brino (Nov 11, 2019)

Crisp and clean. Well done!
-brino


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## MrWhoopee (Nov 11, 2019)

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.


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## Janderso (Nov 11, 2019)

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.


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## darkzero (Nov 11, 2019)

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.


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## MrWhoopee (Nov 11, 2019)

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.


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## GoceKU (Nov 11, 2019)

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.


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## Janderso (Nov 11, 2019)

GoceKU said:


> 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.


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## Bob Korves (Nov 11, 2019)

Your lathe can take the knurling pressure, Jeff.  It is a stout machine.  I agree with the idea to start firmly, much less chance of double cutting, at least when I am doing it.  If you have good quality knurls with beveled edges or crowned cutting faces, and you are doing work with access to the side of where the knurling starts (side relief), you can touch off the tool to the O.D. with the spindle stopped, then move laterally off the work, set in a reasonably stout cut, and then power or hand feed the knurl sideways into the work.  That usually works best for me.


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## savarin (Nov 11, 2019)

I was converted to the camjack knurler very soon after I started suffering from this disease.








						Camjack Knurler
					

Okay, guys. A couple of months ago, I mentioned a Project-in-Waiting  that I called a Camjack Knurler. When you invent something, you're  allowed to make up words, too. It came about because I had checked out  several sites on clamp knurlers. Most seem to use a 6 mm threaded shaft  to apply...




					www.hobby-machinist.com
				







__





						Camjack knurling tool
					





					www.totallyscrewedmachineshop.com
				



I do a lot of knurling in stainless which takes a lot of pressure.
The pins wear and I dont calculate the diameters but the wheels sort of slip on the wear and align themselves.
Clamp very tight and turn slowly usually allows them to slip into the pattern.
In stainless I have to turn the cam bolt with pliers to get full depth. (must make a larger dia knurled top for it.)


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## ttabbal (Nov 11, 2019)

I made a camjack as well. Great tool. Tons of pressure and nice straight knurls.


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## darkzero (Nov 11, 2019)

savarin said:


> I do a lot of knurling in stainless which takes a lot of pressure. The pins wear....



If you have an issue with pins wearing you could try solid carbide pins. I have carbide pins in my Eagle Rock K1-44 (scissor knurler) & never had issues with the pins wearing yet. I mostly knurl titanium with it. It came with carbide pins so not sure how much better they are compared to hardened steel pins.


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