During my first experiments with milling aluminum, I’ve tried both compressed air and my vacuum with Sweepy for clearing chips. Both seem to work equally well but using the vacuum results in significantly less of a mess for me to clean up. Is there a downside to using the vacuum?
-M.
I just did the same thing. The sweepy cleared the chips. Looks good to me, but that doesn’t mean much.
The Sweepy will get scuffed up and not be transparent after some amount of cutting metal (DAMHIKT).
With a vacuum there is some concern about the likelihood of recutting chips in narrow slots or holes.
Compressed air has the advantage of cooling the endmill as well as clearing the chips.
Good insights – thanks.
What this really comes down to for me is whether or not I build a lightweight enclosure for my S5P 2x4. Using compressed air for my early experiments glitter-bombed a significant area in and around my machine. 
-M.
Yeah you can probably get away with just vacuuming. If you want to protect your sweeepy, you can probably just put some protective film on the plastic where the chips hit. Like a film on the window of a sand blasting cabinet 
If you’re going to be doing a lot of metal, the enclosure is probably worth doing eventually.
And as folks have mentioned, narrow or deep slots benefit quite a bit from air blast as a chip clearing method.
The enclosure also facilitates things like mql/mist coolant which can be a big benefit for surface finish on non-ferrous metals (in my experience)
You are supposed to be able to see through the Sweepy ?
That went away a long to ago. 
On my list of things to try for the nomad enclosure is using a large sapphire glass tablet screen protector to keep the plastic see through.
Throw aluminum and brass chips at it all day long and at 7+ on mohs it should last forever 
Another plus, most screen protectors have oleophobic coating so lubricants and such shouldn’t coat them too terribly.