It’s for my MPCNC. Ideally it’ll be only 1 hr at a time or less.
Hmmm… Might run into issues but you wouldn’t know till you test it out
The chamber will be pressurized from the vacuum exhaust, and the air will be pushed out the duct at the back, taking the heat with it. It’s why I wanted the duct drawing air from the top of the enclosure. I realize “hot air rises” is a thing but only in the absence of external forces.
That exhaust pressurization is exactly what you’re trying to avoid with your cyclone first stage… Well, it’s one of the things you’re trying to avoid… You’re just moving the pressure point from the filter bag to the exhaust baffle.
Where is the cold air intake? Your vac is going to be rebreathing its own exhaust, and its ability to cool itself will be significantly impaired. The air coming in from the first stage won’t be cool. It’s been carrying hot dust/chips from your router, and then flinging them around the sides of your cyclone separator.
It may very well work. I honestly don’t know. If you’re set on giving it a shot, go for it! Let us know how it works for you. I’m just voicing my opinions based on what I’ve read, and what I think I understand about the thermodynamics of the situation. 
I may have to add a air intake for the vacuum cooling fan separately, but I want to try it without first. I’ll add a temp sensor to the enclosure so I can keep an eye on it. As for the exhaust pressure, it’ll be a 2" by 20" slot for the air to exhaust so I don’t think it’ll be too bad. I may split the exhaust channel into two parts and duct the vacuum exhaust directly out so there’s less heat buildup.
I built an enclosure for my shop vac a couple of months ago. It’s made of 18mm MDF, with 45mm rockwool (RockSono) padding on the inside and another 8mm MDF box inside of that.
The wooden box you see just below the hose is a sound baffle / exhaust. The hose itself goes through a hole in the side of the enclosure (not visible in the picture).
When I close the door, it’s very silent. Rockwool sandwiched between MDF is very effective, and relatively cheap.
However… it gets very hot within a couple of minutes when I close the door. Hotter than I’m comfortable with. Hot air rising and having pressure inside the chamber did not move the air out quick enough to keep things reasonably cool.
Then I cut a hole in the side where the exhaust is, to let the exhaust air flow out directly. That helped a lot. But the motor still gets a bit warm and still heats up the air in the enclosure. So now I also let the door open a couple of cm’s.
Surprisingly enough, the sound level is a still quite a lot lower even with the exhaust hole and the door cracked open! It’s good enough for me.
I also considered mounting a 12V fan to help the air flow through the exhaust. But given the temperature and just the sheer amount of air coming out the exhaust, I don’t think it will be effective enough. Haven’t tried it though.
I’m thinking of exhausting the air from the motor separately, maybe just using a second layer above the motor. But now I’m concerned about getting the vacuum out easily when I need to check the filter etc. Hmm.
Put a door on the front and use slots or hoses so that you can pull the shop vac out the front.
Yep, that’s the plan. Having a door anyway. It’ll probably be on the side due to the shape of the space it needs to fit into.
Started printing a proper cyclone. The last one worked okay with my small vacuum but the new DeWalt pulls too fast for it. Eta: 2 days. For half of it. 
Edit: Now it says one day. Must have been calculating based on layer time and the first few layers were slow.
1 Like
And since I’m sure someone’s going to say “why didn’t you just buy one” there doesn’t seem to be any local suppliers, so it’s either pay close to $100 CAD or wait 3-6 weeks for shipping from China. A roll of filament costs about $25CAD, so cheaper and faster than either other option.
Good luck on that cyclone! 
Years ago I bought one on Amazon and it was delivered the next day. Might be an advantage of living in Germany.
What 3D printer are you using?
My own mashup of a Hypercube 300 and BLV Cube, 300x3 dual extruder w 1/4" heated bed, flex steel build plate with pei, scratch built.
I’m in Canada and the options on Amazon are shipped from China or too expensive. 
I’m going to cut quite a lot of XPS foam board in the coming weeks. Is a cyclone effective for separating out foam, or is the foam too light?
Honestly no idea. I think it’s primarily for wood chips/dust. The foam might create a bunch of static and just clog it up.
I know magnetic tape will go right through a dust deputy and clog a shop vac impeller.
Huh. For magnetic tape it sounds like your vac should have a bag in it.
I was hoping the cyclone would catch them. 
I’m thinking of just going back to the 5 gallon bucket as a dust collector. I want an easy way to switch buckets if I’m going to mill something other than wood though. I was considering milling a bucket-sized slot into the bottom of the shelf that the cyclone will attach to the top of, and then installing weatherseal in the slot to create the seal. I just need a way to lift the bucket into the slot that I can easily remove.