Knurling 101?

Janderso

Jeff Anderson
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I just found a steady rest for my old South Bend lathe.
The adjusting knobs are missing. I would like to make them, I have one knurling device/tool.
I purchased the Phase II QCTP kit and it camewith a knurling tool.
I was watching some YouTube videos and found out there are several types of these tools.
TPI, specific OD, beveled, scissor, etc.
Please take the confusion out of this question.
I just want to make two simple bands per knob.
Thank you,
Jeff
 
As I understand it, that one that comes with the tool post is a bump knurler. They put a heavier load on the spindle bearings, chuck, etc.. They work, but can be touchy. The scissor type seem more commonly recommended.

To use it, I would make sure the work is tightly held in the chuck and use a live center on the other end.

I'm a noob that hasn't knurled anything, I've just been reading about it. I am planning on waiting to get a scissor type.
 
The scissor type is definitely easier on the machine than the bump type; if you have a small lathe, the scissor type is what you want. Most knurls are of the diametral pitch type, and work best on even fractional diameters; if used on odd diameters, they are liable to double track; for odd diameters, circular pitch knurls work better. One important thing in knurling is to not "***** foot" around, adjust the tool for a lot of initial pressure on the work, this will help to avoid double tracking; when I start a knurl, I do not use the full width of the knurl, maybe half, and when the knurl is established, I then travel to the length required.
 
Take that Knurling tool you have cut the Knurl rollers off with an angle grinder they are a waste of time. Find a scissor type knurling tool.
 
I use a bump knurling tool for very fine knurls, Clamp knurling tools are excellent for anything chunkier, I use an old Brown and Sharpe and a new Integi for most formed knurls.

John Stevenson once knurled a tapered bar to demonstrate that OD/pitch calculation is optional for those with adequate skills, Joe Pie tests the calculated pitch diameters theory in this video and towards the end surprises himself by demonstrating that good technique in applying firm initial pressure produces good knurls on diameters that don't "Match" the pitch of the knurls.


Cut Knurling does benefit from correct diameters but still allows more leeway than you'd think.
 
I think this bump knurled is going in the recycling, paperweight.
Scissor seems the best.
Thank you
 
make one of these
https://www.hobby-machinist.com/threads/camjack-knurler.3533/
I can vouch for its end result.
Do make sure the pins holding the knurls are hardened else you will wear them out. (dont ask me how I know)
If the knurl starts double tracking just clamp down harder till it stops.
Even on stainless I dont have problems any more.
 
I found an app for determining the correct diameter for the knurl pitch. It works very good.
I have only used a bump style with some good name brand knurls I bought used on the bay.
This knob is made of 304ss.
It can be tough to get a perfect looking knurl.
Joe Hynes

20170115_172247.jpg

20170115_171113.jpg
 
I use a scissor type “eagle rock I think” if I see double tracking I tighten it up more and get good knurles .
Knurling kinda moves material more than removing it.
If you remove the knurl wheels off the bump knurler and mount bearings on the end works good to force a part to run truer
In lathe 3jaw
 
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