Thread: Knurler for small hobby lathe

Here's a video I did a while back showing knurling with scissor type.

Build up a worn or undersize shaft - a quick and dirty fix - YouTube

You can also use scissor type the same way as conventional - there is no size limit to what they can handle.

The cheaper scissor knurl like I have can flex when feeding - as seen in the video, and has to be allowed for when setting up.

Using this method has the advantage that you can do multiple knurls on a shaft without changing settings every time you move position.

Rob

Thread has had many good ideas and advice.

In using a knurler tho I have not seen any advice in using if possible tailstock or use of a steady to counter forces. As I said this is not always possible I know.

Does anyone use a steady when knurling?

Originally Posted by wheelinround

Thread has had many good ideas and advice.

In using a knurler tho I have not seen any advice in using if possible tailstock or use of a steady to counter forces. As I said this is not always possible I know.

Does anyone use a steady when knurling?

A knurl applys pressure to the job similar to heavy turning, so you must support the work in the same fashion.

Knurling close to the chuck can actually be a problem at times as the knurl is fairly bulky compared to a cutter.

I generally try to knurl the job early in the piece, so there is plenty of material to support the work.

You can then later machine up to the edge of the pattern, which will give a nice clean edge, where as if you knurl to a shoulder you will get a ragged edge.

Rob

Originally Posted by nearnexus

There's no need for a nut.

The correct way to use a scissor knurl as I was taught is to tighten it down finger tight, back off the cross slide, tighten the knurl another 1/4 turn, and feed the cross slide /knurl back into the work.

You don't screw the bejezzus out of the knurl bolt.

Rob

Rob, would that method still induce pressure on the spindle bearings of the headstock of the lathe?

Originally Posted by Jim Ferrous

Rob, would that method still induce pressure on the spindle bearings of the headstock of the lathe?

There will be some pressure as the knurl wheels roll to mid point, but from then on it's the same amount as when screwing them down at the same point.

As the knurls are only applying pressure in the last few degrees before rolling to dead centre, it will be nothing like the continuous side thrust experienced with a standard straight knurl.

Most of the loading comes from the contained crushing action of the knurl pattern with a scissor knurl.

I was taught to use lube with steel, but never do, and it works OK.

For alloy you should use kero to avoid possible galling.

Rob

I commented in the "checking a surface plate thread", but I used the method that Rob suggested for making a knurled knob today. I have several sets of knurls with different pitches so rather than using a ¹/₄ of a turn, I had a think and brought each knurl in by half the pitch of the knurl and it worked nicely.

P1010951 (Medium).JPG

Michael