Improved Knurling Tool

Billh51

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H-M Supporter Gold Member
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Oct 4, 2014
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Several months ago I purchased a scissor type knurling tool and short of trying it out just to see if it works, it has been sitting in my tool cabinet. It seemed to work ok but it was rather primitive in construction, with loose fitting joints, which made for kind a sloppy assembly. I recently watched a video on You Tube of Winkys Workshop in which he kind of redesigned basically the same tool that I have, making some big improvements which will make it a better tool.
I had some shop time the other day so I thought this would be a good project to see if I could make mine better also, which I believe I did accomplish. One of the problems with mine was the extremely loose fit on the center bolt that the jaws swivel on. The shoulder bolt had about .060“ clearance, which made for a lot of side play on the jaws. The hole was drilled to an exact 1/2” so I just made a new shoulder bolt and also increased the thread size to 7/16”-14 over the 3/8”-16, which was a real improvement and tightened up the jaws real nice. I also switched to a locknut and snugged it up to take out any play.
The base is milled to fit the slot on my lathe compound so it automatically stays at 90° to the lathe bed, assuming the compound is preset for that also. The base started out as a piece of 3/8”-3”x3” angle iron which I cut down and milled to the needed specs. I also drilled a second mounting hole so I can mount it more forward for clearance on larger diameter stock. I then milled a piece to accommodate 1/2”-13 hold down bolt to mount it on the compound. I think the pictures are self explanatory but I would watch Winkys video as he always does an excellent job explaining how he does his projects and I certainly thank him for this one.
I tried it out and it worked great as far as no more slop and and a much more ridged mount to the compound by eliminating all the overhung load with the quick- change and tool holder on the compound. I’m not sure on the knurls themselves, it’s ok but I think the pattern could be better. I may pull the knurls out of my original bump type knurler and give them a try and see if the results are better.
 

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I had a USA made scissors knurl tool that was great, left it at the shop when I sold out, bought a Chineseium replacement which was a POS as you describe; the shoulder bolt is not sloppy, but it does not shoulder up so the nut cannot be tightened so things do no rattle around; it definitely needs the cure!
 
I have one that I bought years ago, it was from India, not eagle quality, but I have no issues with mine, other than when I initially bought it, I could not tell that the pin was (not tapered) but 2 sized. I was trying to knock it out from the wrong side, and bent the casting. No problem though. I do wish they wouldn't have painted over the final assembly like that. The wheels had been protected somehow, but the paint obscured the pin.
 
The first thing you should do when you get something like this, is to make sure that the wheels turn concentrically. All the imports that I have had had lousy wheels. Replacing the lousy wheels with ones that are truly concentric can fix even a crappy knurler.
 
I got my knurl tool out, took it apart for inspection, found that the diameter fits were OK, the problem was that the shoulder was not long enough and that if tightened it was not able to move the scissors arms; I started to make a new shoulder bolt, but then thought, why not just counterbore the scissor half so that the shoulder could meet up with the mounting arm, this require nearly 1/16" depth to be counterbored, and it came out fine, and only took me about 10 years to get to it, thanks to reading this post for prodding me into it. In the process of digging it out, I found I had two, the other with a straight out square bar tapped in its end face for the bolt.
 
I have one that I bought years ago, it was from India, not eagle quality, but I have no issues with mine, other than when I initially bought it, I could not tell that the pin was (not tapered) but 2 sized. I was trying to knock it out from the wrong side, and bent the casting. No problem though. I do wish they wouldn't have painted over the final assembly like that. The wheels had been protected somehow, but the paint obscured the pin.
I believe this one was made in India also and I am not totally bashing it, just needs a little care to make it better than the original manufacturer.
 
I got my knurl tool out, took it apart for inspection, found that the diameter fits were OK, the problem was that the shoulder was not long enough and that if tightened it was not able to move the scissors arms; I started to make a new shoulder bolt, but then thought, why not just counterbore the scissor half so that the shoulder could meet up with the mounting arm, this require nearly 1/16" depth to be counterbored, and it came out fine, and only took me about 10 years to get to it, thanks to reading this post for prodding me into it. In the process of digging it out, I found I had two, the other with a straight out square bar tapped in its end face for the bolt.
Glad to hear you got yours fixed without too much work.
 
The first thing you should do when you get something like this, is to make sure that the wheels turn concentrically. All the imports that I have had had lousy wheels. Replacing the lousy wheels with ones that are truly concentric can fix even a crappy knurler.

I picked up a set of the same tools from India, a large one and a small one. The wheels had a bit more than 10 thousandths runout each.

I replaced the wheels with US made knurls, replaced the axles with hardened tool steel axles, held in with E clips. I also re-reamed the center pivot hole and replaced it with a shoulder screw to get rid of all the slop in the fit. They are amongst my favorite tools now.
 
I would have posted some pics earlier, but I was working out of town. I just got home yesterday.

When I rebuilt them, I did a little cosmetic work too. Cleaned up the surface finish and sprayed then with some Cerakote Cobalt. The small one has fine knurls and the big one has coarse knurls.



High quality wheels make all the difference when knurling.

 
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