Machining Your Own Vs. COTS

[EricH]

Or, as in the case of sprockets (one example), you can get COTS and modify them using the machines, e.g, lightweight them.

[sdcantrell56]

I would say to do a combination of the 2. If you can purchase something that works just a well as what you can make and is cost effective then by all means purchase it. That will save machining time for other more complex things that need to be machined.

As far as using mills to do large things, I somewhat favor it, especially for fabricating drivetrain plates, or things like that just because the accuracy is so much greater than could be achieved with just measuring and a drill press and band saw.