I realize this is an old topic, but in case you are still reading it...
Aluminum can be worked with woodworking tools, like the router in your video. I'd cut the slot with a table saw using a larger version of your jig. Very fast.
You can also save a lot of time by editing your centering scripts to eliminate unnecessary movement at slow speed. By changing to a tooling plate you can eliminate the scripts altogether.
Consider outsourcing. Submit the part for quotes to at least 10 different machine shops, some local, some not. Shipping will be negligible on these parts in quantity.
Another alternative is to use several Taig sized machines, but I doubt you'll beat the outsourcing.
Look to eliminate processes, like deburing before tumbling. A change of media may debur, as well. Use a hold down system that incorporates the table spacing instead of your current clamping. I agree with others that you can mill the holes first, then install bolts to hold down the parts to finish milling without tabs, eliminating a lot of finish work.
--
Ron Thompson Riding my '07 XL883C Sportster
On the Beautiful Florida Space Coast, right beside the Kennedy Space Center, USA
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