Questions on using a moving gantry style mini-mill...

[Davek0974]

Getting near the end of my router/mini-mill build now and need to start looking at how to run jobs, i have a couple lined up already;)

I'm not new to milling - been running a Bridgeport for some years now, not new to CNC - been using a plasma table for a year now, so that should all help. I use SheetCam to produce my G-Code and I think I have it pretty much sussed for the mill now, just looking for tips.

This is the first job - pretty complex but what better way to learn;)

It's from 5mm 6061 Aluminium, has plenty of 3mm holes, slots, square features, its about 320mm long.

So far I am looking at using a 2mm carbide 2-flute cutter, mist coolant, I have figured out how to get sharp corners, also how to spiral-down to cut the holes.

Questions -

1 - I have used a calculator for feeds and got 24,000rpm, 487mm/min feed, 1mm DOC, these seem reasonable?

2 - I am unsure of DOC - this is input rather than output on the feed calculator - how do you know how much bite to take at one pass?

3 - Holding tabs to keep it together on the outside cuts, I'm guessing three or four, 0.5mm thick or less?

4 - Use the one cutter and go straight to dimension or split and do a roughing & finish passes?

5 - Use a bigger cutter for the roughing outside then switch to the 2mm for the finish?

6 - Features like the oval hole - leave it to fall out or use tabs again?

Any suggestions appreciated, I realise this is fairly adventurous but I would like to get these made in-house to increase my profit margin considerably ;)

Thanks