Cutting Aluminium With A Cheapo 3020 CNC

[magicniner]

I'd go with 3mm Single Fute Spiral Cutters like these -

Carbide Engraving CNC Router Bits Single Flute Spiral Endmill Cutting Tool 1/8" | eBay

I've been using one of these cutters to profile small plates from .7mm Titanium plate and it's working very well, I've also found that they're very easy to resharpen on a fine grinding wheel as the geometry of the single flute is not complex.
Stick your work down to a spoil board/plate with strong double sided tape and use a Profiling Feature which ramps down into the work a set depth per circuit of the profile.
Try with a .2mm per pass ramp down into the work and if everything's smooth at that increase your feed until it starts to sound a little less smooth then back off a tad.
For feeds & Speeds download the free trial of HSM Advisor here -

Advanced CNC Speed And Feed Calculator - HSMAdvisor

It's nothing short of toptastic, it gives me a good start point every time and Mach3's feed override allows me to creep up to the edge of the envelope for my job, tooling and setup

[Pointy]

Thanks for the reply.

I noticed that it doesn't list Aluminium as a suitable material for those bits though.

As there seems to be a limited range of bits with a 3.175mm shank, I wondered if it was worth getting another size collet?

Regards,

Les