[soydemadrid]

Hi I hope someone can help. I'm wanting to cut out some aluminium sheet and make letter stencils and metal signs.

I have access to a CNC machine I can borrow that has Vectric Aspire setup - but I'm a completely novice! The machine I'm borrowing only usually does wood too which doesn't help as I can't get tips from the owner!

I basically want to do this but in metal: http://forum.vectric.com/download/fi...4921&mode=view

Now if my metal is only 1.5mm thick or less, what is my best way to do this? I thought I'd probably just use the "Profile" toolpaths but I'm not sure if that is the best way?

Also do I go for the lowest or fastest spindle speed? To prevent the metal warping... Also is it best in 1 pass or several etc?

Sorry for all the questions. I tried to work it out myself by just having a few goes. I wasted quite a bit of metal !! Some of the cuts would have a jaggered raised edge and not smooth, some would warp and parts of letters would fall out or be destroyed etc etc. The spindle would just come in fast and destroy my lovely idea haha. I did use G Wizard Calculator to try work out speeds and such but any tips or what toolpaths to use etc would be really appreciated.

Thanks so much for any help

[robertspark]

What tool are you using (diameter, flutes, material, coating, manufacturer)

Is it an aluminium cutting endmill?

What feed and speed are you using?

[soydemadrid]

Hi thanks for the reply and help.

I am using a solid carbide square endmill 2 flute i believe - not specifically for aluminium. I also have ball nose solid carbide endmills I can use too if they'd work any better for this kind of work?

The endmills I've tried are 1/16" which in the Vectric Aspire toolpath preview looked like it was small enough to keep the detail etc.

The speed I ran at was 27000rpm which in hindsight seems fast??

My feed rate was 14.74 inches per minute which is what I got from Gwizard Calculator with that spindle speed etc.

Let me know if I can give any further details, it would be lovely if I could just cut out from 1.5mm alu sheets effectively and neatly.

Thanks again

I used 4 passes at that speed with a 2d profile toolpath and had some small tabs in there too (with my aim to stop the bits dropping out of the letters cutout and mashing everything up, unfortunately when the metal warped and the edges all burred the tabs didn't hold and it all moved and mashed up anyway!!

[Tigerflyer]

Your feed rate is not even in the ballpark for that rpm. Cut aluminum at .005-.010 chip per tooth. At 27k rpm that would be 250 ipm not 15.

.063” dia bit would be something like 50 ipm at 12,000 rpm