Straddle knurler build, no mill required (we hope!)

[Papa Charlie]

I just measured the opening. The arms can open to 2.125" with no problem. (Actually can go until 2.3".) Not going to machine the arm slots. They are good enough. The limit is not the arms, but the cut out and the spring. The spring just peaks out from the bottom of the arc. No need to risk ruining the part for zero improvement. Have to use the angle blocks for something else...

That is the beauty of the tradition type of knurling tool. It is pushing from one side with the distance between the rollers fixed. You can basically knurl anything that fits in the lathe. But lining them up to get even imprint of from the rollers take a bit of effort using a rocker type tool post.

I am sure there are advantages to this configuration and I am sure that you learned a great deal, working through the build process. I think you did a great job. A lot of thought had to go into this.

 

[WobblyHand]

@Papa Charlie I have a bump knurler. It just pushes against the spindle bearings. The knurling isn't very distinct. It's just ok. (Using the wheels that came with it.)

This kind of knurler puts practically no radial force on the spindle bearings. This may not matter for larger class machines, but for little machines like my mini-lathe it preserves the (cheap) bearings. Right now my indicated spindle runout is like 0.0002", and I'd like to keep it that way. The straddle knurler is limited to 2.125" diameter. That's fine for the bulk of things that I will do. Using the straddle knurler is really easy and has generated some nice knurls for me. If I need to do something larger, I still have the bump knurler.

 

[Papa Charlie]

@Papa Charlie I have a bump knurler. It just pushes against the spindle bearings. The knurling isn't very distinct. It's just ok. (Using the wheels that came with it.)

This kind of knurler puts practically no radial force on the spindle bearings. This may not matter for larger class machines, but for little machines like my mini-lathe it preserves the (cheap) bearings. Right now my indicated spindle runout is like 0.0002", and I'd like to keep it that way. The straddle knurler is limited to 2.125" diameter. That's fine for the bulk of things that I will do. Using the straddle knurler is really easy and has generated some nice knurls for me. If I need to do something larger, I still have the bump knurler.

I can see what you are saying. I have never had to work on anything smaller than my 12x37 Grizzly lathe and I find my Grizzly very limiting. Thanks for explaining this.