good looking machine and nicely done
the problem is that it won't be solid enough for any heavy metal machining , but it doesn't mean that you can't do any ally . wood routers work ok as long as you take passes .05' or less , and looking at the design of your machine I'd imagine that's the max you'd be able to push it on aluminum anyhow .
.05" at 50-100 ipm will remove material quite rapidly as long as you are strategic in your toolpathing . conventional milling will probably produce the best results
. I've managed to cut mild steel at 120 imp with my wood router as a test and it cut it pretty easily , i just wouldn't do it on a regular basis ,
since you've got the router then you may as well throw it on and see what you can do with it
I have to agree somewhat with the last comment and that is if you plan to machine lots of metal then your best option would be to have a mill , or to build a beast that can handle the punishment
A poet knows no boundary yet he is bound to the boundaries of ones own mind !! ........