Black Box Vac Source

Lucas. As you can see I'm new to this also, but I believe the cooling air intake for the motors comes in at the top of one of the end panels & is filtered. If you look at Gary's photos #1 & 4 in post #2 you will see what I'm referring to.

Yes, I see now! Thank you Daren.

Bit of a puzzle this one. A fun challenge.

Thanks again!

Daren...
1) The early design had relays, etc for control, which turned out to be costly and didnt work as well as I wished. The latest versions use one side upper chamber for intake cooling air with filter fabric. Other side upper is unused. The cutouts thru the sides are adjusted accordingly.

2) Yes, but to date havent heard that anyone has had to do that.

3) No, they seem to flow just fine AND most importantly keep cool. If you do this post some pics.

4) I have run all that I have installed on 30A breakers.

Lucas...
See Daren's #1 above

Thanks Gary. I'm starting to get a pretty clear understanding of how your box is designed now. Only a couple questions remain. :confused:

What did you end up using for an air filter in your boxes? I expect it doesn't need to be anything special given that the air is just for cooling the motor. I believe I will also need a filter on the open-air valve in the PVC plumbing, & that one should probably be a bit better seeing as the air goes through the motor. But then again, maybe I'm just over thinking this whole thing & it doesn't matter much either - maybe it's just like my dust collector.

Also, what type of fitting do you use to connect the box to your table plumbing? I'm picturing the box sitting on the floor connected with rigid PVC pipe fittings & then someone walking by bumps the box (or it simply 'walks' a little from motor vibration) causing the connections to break. I'm thinking that you either fasten the box to the floor and/or use some kind of flexible connector.

Daren...
I used a couple layers of spray booth intake (tacky) filter cloth. I have purchased it in the past in 2' by 100' rolls, so I had it on hand.

For the fitting into the box, I used a 3" male threaded adapter glued into the box with silicone. I used a 3" "no hub" connector as a union and vibration isolator between the box and the table manifold.

I used a fully glued spoilboard and never used a filter. But I would never say that using one is not a good idea. Some of the best minds here recommend them.

Gary,
I've never seen it, but that spray booth filter cloth sounds perfect for the vac motor cooling air via the cutout in the black box.

I'm also going to be using a glued-down spoilboard so no filter there. I was thinking however that I should put a filter of some kind on the open air valve (which I believe should be open when starting the vacs to reduce load?). That spray booth filter should work well for that too though.

That no-hub coupling sounds like a good idea for vibration. I'm planning to use a closet flange screwed & siliconed to the box.

Do you fasten the box to the floor somehow? PL400? Rubber feet?

Thank you

I chose not to use a filter on mine. The people who recommend them are correct. A dedicated filter is a good idea, if you want to be sure.

I am willing to take the risk, of relying on my bleeder board to filter the air, as a tradeoff for plumbing that may perhaps be slightly less restrictive. This is only a guess.

I did throughly vacuum out my plenum prior to gluing my bleeder board down. I also made sure to clean all debris from the plumbing, during installation. One chunk of loose crud, can destroy these kinds of motors.

I will have to put some spray booth filter cloth over the intake vent on my enclosure.

This is what I came up with, and my gauges show no difference with or without it in line:
http://www.talkshopbot.com/forum/sho...ghlight=filter

...I finished my box a while ago & have been happily using it with 2 motors (2 more just ordered). Now I'm finally able to post my version of it here along with some pics of this awesome little vac box. Thanks again to Gary for continuing to answer my relentless questions & for sharing his great design - I recognize that it came from a long road of experimenting & improving. So, in keeping with that development, if I'm able to answer any questions or pay-it-forward somehow to help anyone else, don't hesitate to ask. I'll post pics of my table & vacuum plumbing in other more appropriate threads.

I re-drew the entire box in SketchUp so that I could completely understand how everything worked & fit. I also made a couple of small mods:

1) Added a threaded rod 'indicator' to the flapper so that I could see from the outside of the box, which position the flapper was in. It also allowed me to manually set its position in case something didn't work as planned.

2) Removable top & sub-top panels so that I could access the motors.

3) Removable bottom panel to access the air filter.

4) Homemade air filters to all 3 of the different air intakes.

5 more pics