It's surprising what you can cut with a jigsaw. I've used them for 3mm sheet steel in the past.

The big thing you'll need to be aware of is the aluminium sticking to the blade. A little bit WD40 will help avoid sticking, and quite a course blade on thicker plates will help.
If you wanted to get a good edge, you could go to the length of making up router templates, and finishing the edges with a suitable router bit.

It's not ideal, but aluminium can be cut with most carbide wood working bits. Just give them a little coat of some WD40 to avoid sticking, and make sure you're wearing long sleeves and safety glasses.

There is also the possibility of making a crude set of plates, then using the machine itself to make a better set.


For tapping aluminium, I'd advice against general purpose taps.
Get either spiral point (for through holes, as the spiral point pushes the swarf ahead of the tap), or spiral flute (for blind holes, as the swarf travels back along the spirals).
Spiral point is the preferred option, as you don't have to deal with swarf wrapping around, and potentially jamming the tap, but not all holes are going to be through holes.
And run the taps in a cordless drill if you can.

This is the supplier I've used in the past for taps - https://www.ebay.co.uk/str/cncpoorboytoolstore
For aluminium taps, just search their store for Yellow and the size you're looking for, as Europa yellow ring uncoated taps are their better option for aluminium.