Well I went back to the shop and made rubber knurl wheel #2, and #3.
Destroyed # 2 in testing.
Process starts here with the paper roller from a printer. Can't remember what kind. I had already cut one end and a couple of slices off when I took this pic.
Sliced off 3/8" piece for #2, and after destroying that one, cut a slice about 5/16".
Here's slice #3:
I mounted #1 on a long SHCS with the knurl as a diameter gage. I mounted #2 with #1, to make it ~¼" bigger than #1.
I destroyed #2 by making it too wide. I tightened it up too tight in the knurler and it stopped turning after the knurl started to form. /The roughness of the knurl just ground a hunk out of the rubber.
I left slice #3 at the original diameter and just tried it. I also prepared a new piece of aluminum bar. The first test with #3 was pretty good, but I didn't have the knurler perfectly 90° to the work. You can see that on the end of the bar here:
The narrow knurl to the left was another attempt after adjusting the knurler to try to get it square to the material.
My conclusions from this exercise: 1. The process will work, but the rubber wheel needs to be the right size. 2. I need to be much more careful with the setup. 3. Probably quicker and better results would be obtained with a purchased set of knurls.
You can see from the results I have a lot to learn about knurling. The knurls were formed deep enough with the rubber wheel as the supporting second knurl, but the tool either shifted or I didn't have it lined up good enough. I probably would have had better results if the surface to be knurled was proud of the rest of the material by more than the depth of knurl desired.
Comments/criticism welcome¦
Chuck in E. TN
Destroyed # 2 in testing.
Process starts here with the paper roller from a printer. Can't remember what kind. I had already cut one end and a couple of slices off when I took this pic.
Sliced off 3/8" piece for #2, and after destroying that one, cut a slice about 5/16".
Here's slice #3:
I mounted #1 on a long SHCS with the knurl as a diameter gage. I mounted #2 with #1, to make it ~¼" bigger than #1.
I destroyed #2 by making it too wide. I tightened it up too tight in the knurler and it stopped turning after the knurl started to form. /The roughness of the knurl just ground a hunk out of the rubber.
I left slice #3 at the original diameter and just tried it. I also prepared a new piece of aluminum bar. The first test with #3 was pretty good, but I didn't have the knurler perfectly 90° to the work. You can see that on the end of the bar here:
The narrow knurl to the left was another attempt after adjusting the knurler to try to get it square to the material.
My conclusions from this exercise: 1. The process will work, but the rubber wheel needs to be the right size. 2. I need to be much more careful with the setup. 3. Probably quicker and better results would be obtained with a purchased set of knurls.
You can see from the results I have a lot to learn about knurling. The knurls were formed deep enough with the rubber wheel as the supporting second knurl, but the tool either shifted or I didn't have it lined up good enough. I probably would have had better results if the surface to be knurled was proud of the rest of the material by more than the depth of knurl desired.
Comments/criticism welcome¦
Chuck in E. TN
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