DIY Build of Aluminium CNC Wood Router without Workshop & Tools

[WandrinAndy]

Am busy "tooling up" for my build and I need to buy some taps for threading alu plate, and [possibly] the cores of alu extrusion... and have a few queries please:

I'm guessing that M5, M6, M8, and M12 should cover my needs.

What type of thread are the bolts that most peeps use... metric coarse or metric fine?

I will be using KJN 45x90 Heavy extrusion which has ribbed cores that I think have an internal diameter of 10mm and outer diameter of about 16-17mm. The core-bolts that can be bought from KJN are M12x30, and I think they have two versions of these, one of which is self tapping. Sadly these bolts don't use normal allen-keys £!*%!.

Wanting the frame to be as rigid as possible... Are these M12x30 bolts sufficient, are the self-tapping version sufficent, or would it be better to drill and tap for using bigger bolts?

Sorry about all the little questions, just need some help.

Andy

[JAZZCNC]

Metric course: Buy spiral flute taps they make light work of hand tapping in aluminium.

Don't use the self tapping things KJN sell they are rubbish stripping heads very easy. Just normal M12 socket or button heads are fine for this profile.