Thread: Bike Bobber
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Old 04-22-2014, 12:18 AM
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massdrive massdrive is offline
Motorized Bicycle Elite Member
Join Date: Oct 2013
Location: Las Vegas
Posts: 455
Default Bike Bobber

Another bike another coaster brake arm needed to fit around a rear sprocket on an adaptor. I started with 1" x 1/8" cold roll box tubing. Why such a stout choice of material for a coaster brake arm? Because I had a 10 ft. length literally laying around on the floor. I lopped off 20", just eyeballed it. Then I split it length wise about 1/4" thick, again I just eyeballed it. At this point it is hard not to notice that my work piece warped as I split it on the saw. This is to be expected when ever you apply friction and/or heat to thin metal and will be easily dealt with later in the process.
So now I have turned a piece of 1" box steel into a piece of 1" x 1/8" x 3/16" x 20" steel u-channel. I eyeballed the u-channel and sawed it in two. I chucked each 10" length one at a time onto parallels in a power lock vise and milled them 3" at a time down to 3/16" thick. Than using a belt sander I de burred the u-channel's and ground a 1/16 x 45 degree chamfer along the length of the outside edges. Again I just eyeballed it.
Attached Images
File Type: jpg 01_splitting the box tube.JPG (206.6 KB, 70 views)
File Type: jpg 02.JPG (122.6 KB, 64 views)
File Type: jpg 03_saw the u-channel in two.JPG (235.0 KB, 63 views)
File Type: jpg 04_mill down to .18 in..JPG (217.3 KB, 62 views)
File Type: jpg 05_45 degree x .06 in. chamfer.JPG (173.0 KB, 64 views)
If you have to force it there must be a better way
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