I had an opportunity to cut a front brake disc for my GT250 out of 5 mm thick stainless steel sheet using abrasive water jet cutting. After googling and looking at different front brake disc designs I decided go with similar style used in aftermarket Triumph Speed Twin front brake discs. Once I was happy with the 3D-model I exported it to a DXF file which was used to program routing for the cutting machine.
After cutting I machined grooves around each bolt hole used to fix the brake disc to the front wheel hub with 14 mm square mill in a vertical milling machine. Once that was done I sand blasted the disc to get a good surface for paint.
This time I decided to use simple spray paint. Before painting I masked outer edges of the disc and cleaned all the surfaces I wanted to paint with acetone. I applied a thin coat first which supposed to help the next heavier coats to stick better. Instructions in the can said to use primer when necessary so I opted to leave it out. I'm curious too see how it works without primer. If it doesn't I will prep it and paint it again. Once paint had cured I installed the disc with a 12 mm spacer I also got cut with abrasive water jet cutter and rolled the bike outside to snap few pictures of it 😊
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| Design for front brake disc |
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| Dimensions |
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| Blank |
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| Grooves for socket cap screws machined with square end mill in a vertical milling machine |
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| Sand blasting before... |
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| ...masking and coat of matte black spray paint |
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| Dimensions for spacer |
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| I painted the outer surface also with matte black |
