Knurling attachment question (scissor or clamp type?)

[mickri]

Did a search online for DIY knurling tool and found this. https://www.hobby-machinist.com/threads/knurling-tool.15151/#post-117927. There were lots of pictures of knurling tools that people had made.

 

[savarin]

The amount of pressure that top piece applies to the two arms with just finger tightness..
If your knurls are not tracking correctly then a quick twist applies so much pressure they just slip into alignment.
I never calculate the work dia when knurling, if they double track then I just apply more pressure and bingo, now they track.

 

[ARC-170]

Did a search online for DIY knurling tool and found this. https://www.hobby-machinist.com/threads/knurling-tool.15151/#post-117927. There were lots of pictures of knurling tools that people had made.

Thanks! I like the Kant-Twist clamp idea.

Questions:

1. I'd have to drill out the rivets holding the clamp pads to the jaws and then use drill rod as an axle; that would be able to withstand the pressure. But, how would I hold the axles in place? Light press fit? I can't machine a groove for a lock ring in the pin since the material is too hard.

2. What about a bolt thru a steel bushing/axle? The bushing/axle is wider than the jaws by a few thousands, allowing the nut to be tight, but rotate. See attached drawing. The gaps between parts are exaggerated. Of course, there's the issue of being able to withstand the clamping force.


3. Would a steel pin with grooves for lock rings work? This is for occasional hobby use, not production. I could lube it when I use it.

4. What about a rivet thru a bushing/axle? The wheel rides on the bushing/axle, not the rivet.

 

[mickri]

I think that all of your ideas might work. Another possibility is to use push nuts on the pins. Don't laugh too hard. On my 3x6 bandsaw the guide rollers are held in place by tiny C clips. One would not stay in place and the roller kept sliding down its post. I had the same problem with no way to machine the hardened post. As an interim solution I put a push nut on it. It's been over a year and the push nut is looking more permanent all the time. I do have to periodically re seat the push nut. I am thinking of adding a push washer followed by the push nut.

Something else that might work is to use a SS clevis pin. You can get them in any marine store.

 

[ttabbal]

You could use a cutoff wheel in a dremel to cut a groove for retaining the axle. You would probably need a tool post holder for it to get one all the way around the pin, but you could do one side and use a washer or similar with a threaded hole to the side to retain the pin.