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View Full Version : Vac box setup - Complete



aschutsky
04-20-2014, 10:37 AM
After a month or so of build time (sadly) my vac setup is mostly complete. Free time has been limited with a busy work schedule (the bot is a hobby for me) and a 7 month old in the house. :p

Details: 4 X lighthouse 7123 motors in 240V configuration in Gary Campbell's 'blackbox' design. DIY filter box housing a Rigid shopvac filter on the end of a 4" pipe. Enclosures made from 23/32" "cabinet grade" ply from home depot. I used an electrical sub panel with 4 X 10A 240V breakers to control and protect each motor. I'm using a 4 zone setup with ultralite MDF bleeder board. The bleeder board has foil tape around it to seal the edges (as per Brady - thanks!).

Testing: I haven't run them for more than 5-6 minutes but they seem to pull a lot of air! With all zones closed and without the filter box in line I pull about ~8" hg. Adding the filter box in the mix adds a bit of restriction and it will pull about ~6.5"hg with the zones closed. I tested using a board (roughly 24x18) and 1 zone open with the filter box in the mix and it seems to hold very well! I'll probably experiment with making a larger/more efficient filter enclosure to try to make things more efficient, but this is more than enough to get my cutting sheet goods for now. Also per some recommendations I've seen on here I ordered an indoor/outdoor thermometer to keep an eye on temps. Once that arrives I'll put the cover on the top of the motors on.

Lessons learned: Some of you may have seen my other thread where I had trouble getting the motors running. I had not realized I had tightened the motors down too much and all 4 of them were rubbing and 2 of them were completely stuck! With just a few seconds of test time I had lost one of the motor to heat. It is very important that you run the gaskets with the motors and check them freewheel to ensure there is no restrictions!!! Fortunately Ward took care of me and I was up and running in no time. I believe he is going to require the gaskets be included with the motors now.

Pics - note many of these were taken before the gaskets were in place!
http://i164.photobucket.com/albums/u12/aschutsky/shopbot%20vac%20table/9D63146A-3570-415A-AADA-09974390AC77_zpsfqm4d5nf.jpg
http://i164.photobucket.com/albums/u12/aschutsky/shopbot%20vac%20table/6BA9F8A0-4DCF-43C4-9000-24B34E7E5BC2_zpsddllro84.jpg
http://i164.photobucket.com/albums/u12/aschutsky/shopbot%20vac%20table/B7D1F2A8-60DF-4F45-A150-903C66DB2C43_zpsqfeoyi6x.jpg

aschutsky
04-20-2014, 10:41 AM
More:
http://i164.photobucket.com/albums/u12/aschutsky/shopbot%20vac%20table/65A2D4CB-250D-4871-8E0B-4A286FEED11D_zpscamzbq8c.jpg
http://i164.photobucket.com/albums/u12/aschutsky/shopbot%20vac%20table/F6DF9B00-B1B2-4EB0-B189-2D5EFCB55D4B_zpstdseofxp.jpg
http://i164.photobucket.com/albums/u12/aschutsky/shopbot%20vac%20table/E94BA1ED-9429-4B11-AF2A-67C80FDB3AEE_zpsyaqmsmvc.jpg

aschutsky
04-20-2014, 10:42 AM
http://i164.photobucket.com/albums/u12/aschutsky/shopbot%20vac%20table/6698B0D3-9080-4CDF-BA6A-6410DB95847D_zpsgvhr5d4a.jpg

aschutsky
04-23-2014, 07:43 PM
I just got done playing with it doing some testing and the setup seems to be working great. I ran it for about 15 minutes this time just trying out different pieces down to a small 8 x 20" piece with holes in the middle of it. Even using a small warped board (18x24ish) and bleeding off the rest of the air in a zone it still provides tremendous holding force. I had to take a quick video - it may not be too obvious but I'm pressing VERY hard on each side of the board here. Watch closely when I shut the vac off and you can see the warp of the board. :D

Vac box DIY testing (http://youtu.be/u1X9aY9qT6k)

I'm going to build a box with just 2 motors as I think that will still be more than I would need for 99% of the time. This would kick out less heat and waste less energy for most of my cutting. After running for about 15 minutes I saw temps up to about 130 degrees while a bit of air was being bled off. Is this too hot? Sensor attached directly to metal housing of motor #1.

coryatjohn
04-23-2014, 08:18 PM
I made airfilters out of 8" PVC. The top and bottom I made with the SB. They turned out pretty nice.

http://usnaviguide.com/shopbot/aircleaner.jpg

aschutsky
04-24-2014, 08:56 AM
I made airfilters out of 8" PVC. The top and bottom I made with the SB. They turned out pretty nice.


John - Interesting. Have you measured pressure loss before/after the filter by any chance?

coryatjohn
04-24-2014, 11:10 AM
John - Interesting. Have you measured pressure loss before/after the filter by any chance?

The pressure loss is zero, or more precisely, unmeasurable. You have to remember the actual airflow through a vacuum hold down system is negligible. We all use these giant PVC pipes (2-4") to plumb these systems but in reality, a 1/2" PVC pipe would work as well as a 2". The only benefit larger diameter pipe has is in the initial evacuation of the system when the vacuum is first turned on. After that, it's static, or should be.

More air flows through the relief valve then the rest of the system.

David Iannone
01-15-2015, 10:30 AM
I like the filter design John.