What’s wrong with my knurling

Hopper: That article was the first one I ever submitted for publication .I'm pleased you're happy with it. A couple of people at my club made one, but I had no idea if anyone else had bothered.

I got some different sized knurl wheels but had problems keeping everything together, so designed and 3D printed a fitted case for it all.

Here are the components of the tool.

and an example of what it can do.

From what I can see in the OP's photograph it would seem the Knurls have been presented to the work in the centre of the diameter to be knurled.

This is not something I would do.

I have detailed my method elsewhere on the forum under a similar heading. Perhaps one kind Moderator might provide a link?

The pattern shown in the workpiece left by the wheels leads me to think the axles are not parallel to the work axis in both the horizontal and vertical planes. (This may be a defect in the tool construction, or mounting). This is a critical requirement with scissors knurling tools. Also critical is the side to side movement of the arms of the knurling tool. Each wheel is fighting to move sideways due to the resultant forces involved. The wheels are no different to a Helical Gear and these need to be paired in a gearbox to cancel out axial forces. Any play in the arms will therefore be exploited by the knurls at the expense of the finished knurling.

Small diameters usually benefit from straight knurling.

Regards

Gray,

Dell,

Clamp the knurling wheels on to the so they contact at points 7 and 11 o'clock looking from the tailstock. I appreciate your hand problem, so now you feed in on the cross slide. The force from the cross slide is greatly multiplied as the knurl wheels ride up toward the 6 and 12 o'clock points.

Gary,

I just have to ask what nicely knurled widget in photo 3 is for?

Martin

Mentioned above by Graham Meek, the sideways movement of the arms can cause poor / uneven knurls. I built the device shown below which is designed to eliminate sideways arm movement. Shown with straight knurls, but there are various interchangeable sets of wheels.

Thanks once again for the replies, I will do a bit more experimenting, I am not able to drill the knurled knob on the tool because the threaded stud comes all the way through, so I will try what JasonB suggests first and if that doesn’t work then maybe mill two flats on the knurled part of the tool to be able to use a spanner.

Dell

Dell link to another video on subject link

https://www.youtube.com/watch?v=qySEfau12Z4

H

Dell, you mentioned knurling a spring loaded Tap Follower. I’ve made several of these and I didn’t knurl any of them. I did buy one first that was knurled, but it was such poor quality that I had to remake some of the internals. I’m not too sure why the knurled it though?

It's a spring winder - lets you make evenly spaced springs on the lathe.

The reason for knurling was so I can remove the base to turn the inner part round as it’s going to have a point on one end and a divot in the other so I can use it for bothe my BA and metric taps.

Dell

Thank you, I have learned something today. A very neat solution, beautifully executed.

Martin