Detail 02, the Spindle Housing
Since I started the Spindle Housings while working on the gears, it was time to finish them. I started by constructing my tooling block to hold the housings while machining the business end. I’m not a big fan of layout fluid, scribing, and center punching so all of my machining was done in the mill using an edge finder and DRO for positioning.
Here I’m using an indicator to set the 60° angle. A little trig and a little tapping and I ended up with 59.96°. I needed this pretty close since I was going to be working off of CAD calculated dimensions.
When I squared this block up, I purposefully did not break the front edge so that I could use an edge finder to locate it fairly accurately. Once I locate the sharp corner, I machined off 0.100″ to give a square face to locate from in the future.
With the 1/2″ bore finished, I opened up the 13/16″ clearance area 0.375″ down from the sharp back corner, and then made a close fit ø0.615″ bore 0.750″ total down from the sharp back corner. The ø0.615″ bore needed to be a close fit to the Spindle Housings as well since this is the clamping surface. Be sure and check both Spindle Housings in the fixture at this point.
I didn’t like the mark left by the setscrew in Michael’s fixture so I decided to change to a pinch bolt clamp. With the fixture still clamped at 30° I ran a 1/32″ slitting saw just above the bottom of the ø0.615″ bore so that the seating surface would not be affected.
Since everything was done in CAD, its a simple matter of indicating the block and moving over to the hole location. Since I wanted to make sure and not cause the part to rotate while drilling, I stepped up the drill sizes to 19/64″.
By doing 0.005″ step overs, I ended up with a flat bottom counterbore without having to face the bottom. My eBay Wohlhaupter boring head could have easily faced the bottom, but since my boring bar was so small I needed to use small steps anyway.
Only after all of these steps were completed on the first Spindle Housing was the fixture clamp screw loosened and the housing removed. The second housing was installed in the fixture and the process repeated.
Both housings were deburred, and the ball bearing ODs were coated with a light coat of retaining compound and the bearings pushed home. A light coat of retaining compound was placed only near the shoulder on the spindles and the Spindle Housing with bearing and bushing was lowered over it. These were left in an upright position while drying to make sure no retaining compound wicked between the spindle and bronze bushing.
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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)