any thoughts on this blower

[michael_schwartz]

http://www.republicsales.com/documents/Republic-Regenerative-Blower/Spec%20Sheets/HRB501-50-60.pdf

The specifications are for a max vacuum of 79" H20, and open flow of 212 CFM.
This is with a single phase 3HP 220v motor, at 76DB.

The working vacuum would be approximately 79" H20 at 130 CFM, up to 160 or more before it drops below 4" HG.

Compared to the LH6765-13 central vac motors I have (Max 140" H20, 106 CFM open flow) A more realistic flow rate is about 60 CFM at 72" H20. They drop off below 4" HG with another 10-20 CFM.

I am thinking of going with the best of both worlds and using the central vac motors when I need the suction, and then the small regenerative blower in lieu of a second set of central vac motors when CFM is more important.

5.8" HG is barely enough but of course my understanding of vacuum hold down is that either less is more, or you can never have enough, because the guys with 40hp blowers still wish they had more.

I don't want to invest too much in these central vac motors. My electrician doesn't like them, and of course a regenerative blower is designed to last for tens of thousands of hours, not hundreds.

[knight_toolworks]

Till I made a vac box for my feins I had that low of " and it was marginal sometimes.
I have seen better specs in the 900 to 1200 price range how much is this one?
what I found is the blowers are at best the same and usually worse in performance over a small blower at 5 times the cost. Unless you can get a big one they just don't seem worth the cost.

[michael_schwartz]

I am not sure. The 2hp version is on Ebay for 900 or so. I am going to look at more spec sheets, but this is the best I have found so far. I am sure there are dozens more to look at.

[knight_toolworks]

I think 120 to 130" is about the min you want to shoot for.
but for that size you really need two to equal what you have now. Thats the problem I ran into unless you can get something around 7hp or larger your ok anything less and the cost just does not seem like a good deal.

[michael_schwartz]

Thats what I am finding is that there is a real drop off in performance with anything under 5-7HP 3Phase.

[Brady Watson]

Republic makes a good blower at a good price. However, the one you have spec'd out is not worth investing in It maxes out under 6 Hg". A Rigid shopvac will do those numbers for $49. I'd rather see you go for the used Roots blower listed today. They can be loud, but they work really well.

There is little to nothing cost/performance wise between the Lighthouse motors that I found years ago after a lot of research, and a professional level pump. You can drive yourself nuts to save a few bucks...or something that runs on single phase without a converter.

-B

[michael_schwartz]

The limitation is that I have 100 amp service. I agree that the professional setups are the way to go. If I had the power available I wouldn't hesitate to buy something in the 10-15 HP range. Even 40 amps for the single phase roots blower would be a stretch.

Thanks for the input though on the aforementioned republic blower.

[kevin]

http://www.talkshopbot.com/forum/showthread.php?t=14562

Hurry before its sold

You won't regret it

[knight_toolworks]

will more inches of vacuum help keep thinner materials from lifting up? thats my main problem with my setup when I am cutting thin plastics like .03 I have ways of dealing with it but my one hope was holding it down with just vac.
well even thicker plastic can lift up.

[Brady Watson]

will more inches of vacuum help keep thinner materials from lifting up?

Yes.

Plus, don't use an upcut. Go with a straight if you can. No downcut.

You can use my Vacuum Film technique to hold just about ANYTHING down without ever breaking through vacuum. This is how you cut tiny parts in a production run with or without a big pump.

-B

[knight_toolworks]

can you cut acrylic with a straight bit? I can't remember if I tried it or not. I use double sided tape or the pressure foot or spray adhesive on the spoilboard depending on what I am cutting.
I am not talking the parts lifting up but the sheet it's self lifting. But of course that is the upcut but I have always used upcuts on plastic to keep the melting from happening.

[bleeth]

Steve: Acrylic cuts very well with O flute straight bits. If you are stuck cutting extruded instead of cast it definately is the way to go. Onsrud has some really nice ones that last well also.

[michael_schwartz]

I should have the lighthouse motors up and running soon. I fired them up with the box I had built to test them but I am scrapping that.

After consulting with my electrician am going to enclose the motors in a 12x24,x24 NEMA type 1 14 gauge steel enclosure with louvered vents.

I am going to mill flanges/motor mounts from 1.25" thick type 1 grey pvc, and put a .375" pvc divider in the enclosure to separate the intake air from exhaust. The blower exhaust will get plumbed out the back of the enclosure, and I will eventually add mufflers.

I am going to setup a simple pvc manifold, and I ordered a pair of full flow pvc check valves. So far I like the knife valves I ordered, although I haven't had a chance to test them under vacuum.

The electricians also setup a control enclosure today to house the switches, fuses, and a panel mounted vacuum gauge. This will be mounted to a new computer cabinet I plan to build this week.

I should have this project completed sometime next week, and I will post all the details.