I began the final assembly with the fitting of the levers. First the height adjust lock lever was installed and a measurement was taken for a test shim. I added an extra 0.01″ to account for the fact that the lever was not tightened at this point. A quick test shim was made without the locking lip.
The test shim was installed and the lever tightened as shown in the photo. I want the tightened lever to be approximately parallel with the shank and based on this photo it should turn about 135° more.
That gave me an adjusted washer thickness of 0.083″. A new blank for the locking lever washer, Detail 16, was then turned with an overall thickness of 0.083″ + 0.031″ for the anti-rotation tab.
Next, the spindles were temporarily inserted, and the bottom cotter and the lengthened top cotter were installed with the height locking screw. I wanted the lock and unlocked positions for this lever to be located above the body with the full lock position to be with the right side of the lever aligned with the upper right corner of the body block. Based on this image, I need to rotate the lever an additional 142°.
Using the same math as before, I removed 142/360 / 28 = 0.0141″ from the end of the top cotter. I chose not to add the coping cut at the top of the cotter as I felt that it was mostly hidden by the lever and the reduced bearing surface could cause early failure.
At this point, I temporarily assembled the knurler with some temporary knobs so that I could use it to knurl details 12 and 21. Here, I’m starting on Detail 12, the Height Screw Knob.
The diameter is 5/16″ nominal and this was adjusted based on the knurls I was using. The circumference of the nominal size would be 0.3125″ * π = 0.98175″. This length using 40LPI knurls would produce 0.91875″ * 40 = 39.2699 lines. Therefore, to get rid of any partial knurl lines the diameter should be adjusted to: 39 / 40 / π = 0.310″. Many say this adjustment is not needed when knurling but it takes only seconds to calculate and it certainly can’t hurt.
Next, I rough turned the OD for the Spindle Adjustment Knob, Detail 21. The knurled portion is specified as 0.625″ but again I adjusted this based on my 40 LPI knurls. The actual diameter I turned was 78 / 40 / π = 0.621″
A few shots of the finished cut knurling tool.
Every good tool deserves a nice fitted wooden case don’t you think?
Disclaimer and License
All material, including the CAD drawings, relating to the construction of the Cut Knurling Tool presented on this site is free to use any way you see fit. However, no guarantees are made regarding the accuracy or correctness of the material presented here.
(CAD drawings are in SolidWorks 2013 Format)