Caution – technical content, read at your own risk
The new “thing” in business is bringing manufacturing back to the US, “reshoring.” Well, I’m “re-porching” production of the everything bag mount back to my porch, rather than a local CNC machine shop (exceptional shop by the way, I’ve sent and will continue to send them business). I used to make an older version of this mount myself but then made the design more complex, requiring milling. Here’s the new process.
- Cut to length with chop saw
- Drill holes with hand built drill jig, hole locations are within 0.005″ which is as good as you can hope for on a drill press without resorting to extraordinary measures (gauge blocks to line up for drilling etc), and is approaching the spindle run out of the machine.
- Deburr holes
- Power tap on drill press M5x0.8 threads in holes for standard bottle cage bolt.
- Bolt multiple mounts into milling fixture and secure fixture in vise
- Rough “mill” out aluminum slots with circular saw (poor man’s horizontal milling machine)
- I may come up with a way to mill this on my old metal lathe but need to tinker with that more and invest in some tooling.
- File off saw marks with course file (farrier’s hoof rasp/file works great for roughing aluminum), then a few passes with a fine file to finish and break the edges
- The end result has a nice tight hole location tolerance due to the drill jig, the end cuts and grooves have a few signs of hand work, but that doesn’t change the performance of the product in any way. Tighter tolerances (sub 0.010″) could be easily achieved on the groove and end cuts, but there would be no benefit to the performance of the product, and it would become much more time consuming.
- The last two photos show two of the home machined mounts on the outsides posing with one CNC machined mount in between them.