I'm new to CNC work. I have a background in electronics and have recently built a CNC router out of 8020 extrusions with a PorterCable 690 1 3/4 hp router as a spindle. I have a VFD and can run the router between 8250 rpm and 27500 rpm.

I work in the marine industry and will be cutting mostly wood, plastic such as StarBoard, some aluminum as well as engraving electrical panels and other engravable materials.

What is the best way to drill holes in these various materials?

It seems that using the 1/4" endmill is a great way to drill 1/4" holes, but what about smaller and larger holes?

Are there special drill bits with a 1/2" or 1/4" shank available?

Is it reliable to spiral drill holes larger than 1/4"?

Any ideas are welcome. If this topic has been discussed before feel free to post links, I'm new here and still don't know where all of the good info is.

Thanks,
James