what bit for cutting aluminum sheet metal?

[eelnad]

hello, i need to cut out several simple 10" diameter rings out of flimsy aluminum sheet metal. these rings will also have 1/8" holes drilled out along the center of the ring. so i was hoping to use an 1/8" diameter bit for the drilling and cutting so i don't have to do a tool change. i have my original shopbot starter set Onsrud 77-102 bit. i never used it. it appears to be an upcut spiral. can i use this bit for drilling/cutting and if so what feed rate and spindle rpm? or if i shouldn't use that bit, what do you guys recommend? thanks!

[Brady Watson]

You don't want to use that bit. It is 'all wrong' in a number of ways.

How many of these parts in 'flimsy aluminum' (what is the exact thickness, what is the alloy?) do you need to cut out?

A 63-603 would be my choice if you had good hold down. Otherwise, use the downcutting variant of the same bit.

Avoid drilling. Use an inside profile for the holes with spiral ramp step down. Then do the outside profile. No tool change needed.

-B

[Simops]

I've cut aluminium.....anything less than 2mm thick and you risk the aluminium rising during cut ruining the piece.......unless you use vac table or heaps of double sided tape. The later is an absolute PITA for me so now have vac table and it's a pleasure to cut thin aluminium! I use downcut spiral O bits 1/8 or 3/16 (my favourite) on 1/4" shank. Hold down is important consideration when cutting alum sheet.
Cheers

[rb99]

You can cover the sheet with transfer tape (sign making letter transfer tape), then apply aggressive 2 sided tape. I used to spray 3M 77 glue. Removal from parts is way easier.

[Plyoboxwarehouse]

A little off topic, but related to cutting aluminum. I have an aluminum bar that I plan on carving into. Carving the owner's name into it. I have an Amana 90 degree v bit to use to cut the lettering. What feed, speed and pass depth should I use?

[Brady Watson]

A little off topic, but related to cutting aluminum. I have an aluminum bar that I plan on carving into. Carving the owner's name into it. I have an Amana 90 degree v bit to use to cut the lettering. What feed, speed and pass depth should I use?

MS,0,0

You do NOT want to use brazed on v-bits to engrave AL. Either invest in a proper engraving tool or use a Mill/Drill. Then start at MS,0.7,0.5

-B