Need lots of Basic DC Advice

[Brody Goodwine]

Well, I've decided to go with the HF "2hp" motor connected to the "eastcaroga" cyclone with venting outside for my DC setup. I'm a weekend hobbyist, and understand it's not a perfect setup, but it's got a small footprint, which was a big goal.

LOTS of questions from this point. DC is such a "debate" topic that my searches just weren't that educational.

1) What type of rigid pipe is preferred? My runs are short so $$ isn't a huge factor. I'm not too concerned about static after reading the FWW research on it. I do want the install to look clean and flow as best possible. Any advice on sealing connections?

2) The HF input is 5" and will connect within a couple feet to the 4" cyclone out. Is this an issue in any way? The cyclone input is 4", should I go to back to a larger tube for the 6' after just to neck back down to a flex hose?

3) What are the main noise producers in my DC system? I'll be flipping mine on/off via remote, but figure at the point of design I might as well try to avoid noise issues as best possible. The HF unit (in original form) doesn't bother me too much, but the less the better of course.

4) I only have an approx 2' x 1' footprint under the cyclone for a collection box, and plan to just build something with a window for collection. The issue is I can't think of a good way to connect it all for easy unloading. Ideas?

Thanks in advance!

[Greg Peterson]

Wynn Environmental carries 5" flex hose. I run about a 8' length directly to whatever tool I am using. I'm skeptical of this units ability to deliver adequate performance via a network of ducting.

[David Kumm]

While the direct vent to the outside will help you are asking a lot to pipe through a small cyclone with a 4" inlet or outlet. The smaller the cyclone the greater the pressure drop and the reduction in pipe will be a killer. With a 2 hp impeller you want a little oversized rather than under. I like spiral with large radius ells if you need any. For now I would screw and tape the joints. I think you will be reinventing the wheel in the future- as have most of us. Dave

[Brody Goodwine]

Greg, it's not much of a "network", just machine->flex hose(8'-10')->drop to floor(5')->cyclone(3')->impeller(2')->out(3') I may add one wye/blast gate for a floor sweep or vacuum, but basicly no branching.

5" would be irritating since it's hard to buy, but if it really helps that much in light of a 4" cyclone I'd consider it.

Being a hobbyist I really don't plan on redoing it much (unless it just can't perform at all), mainly bc my garage size will limit most any change.

[Brody Goodwine]

More "Vacuum" Questions

5) Could the DC function effectively as a floor sweep if necked down to 2.5" (or whatever)? I'm not sure I fully understand the DC vs vacuum relationship. I know DC is all about CFM, but it would be nice if it could double as my shop vac (that buys me back a 2' x 2' footprint).

6) Why are shop vacs rated so much higher in terms of HP than much larger DC units?

[Jim Neeley]

More "Vacuum" Questions

5) Could the DC function effectively as a floor sweep if necked down to 2.5" (or whatever)? I'm not sure I fully understand the DC vs vacuum relationship. I know DC is all about CFM, but it would be nice if it could double as my shop vac (that buys me back a 2' x 2' footprint).

6) Why are shop vacs rated so much higher in terms of HP than much larger DC units?

5) Yes, but do not neck it way down or you will kill the performance. You want the volume of air to pick up the dust, shavings and chips. You're not trying to pick up dense things like water. Performance on "blocks" of wood may be iffy at 2hp; I do not know.

6) I call it the "miracle of modern marketing" as, bottom line, it's bullsh*t. The vacuum manufacturers have come up with a "technically not lieing but totally misleading" method of assessing horsepower since (1) the vacuum will never load the motor to that level and (2) if it did, the vacuum would burn up if it didn't pop a breaker first.

In my professional opinion it is an inexcuseable marketing move that should be shut down under the consumer protection laws.

Jim Neeley
Reg. Prof. Elec. Engr.

[Greg Peterson]

I'm not sure I understand the configuration you are proposing. What is this cyclone unit you are planning on using?

I don't know that a cyclone is going to scrub the fines any more effectively than the Thien baffle. The cyclone or Thein baffle will get the bigger/heavier stuff to fall out of the air stream, but you're still going to be direct venting a lot of fines, cyclone or not.

[Brody Goodwine]

5) Yes, but do not neck it way down or you will kill the performance. You want the volume of air to pick up the dust, shavings and chips. You're not trying to pick up dense things like water. Performance on "blocks" of wood may be iffy at 2hp; I do not know..

I'm just wondering if I hooked up my 2.5" shop vac stuff if the DC would be a superior vacuum? I would presume so, but just wanted to make sure there wasn't some detail I missed.

6) I call it the "miracle of modern marketing" as, bottom line, it's bullsh*t. The vacuum manufacturers have come up with a "technically not lieing but totally misleading" method of assessing horsepower since (1) the vacuum will never load the motor to that level and (2) if it did, the vacuum would burn up if it didn't pop a breaker first.

In my professional opinion it is an inexcuseable marketing move that should be shut down under the consumer protection laws.

Jim Neeley
Reg. Prof. Elec. Engr.

Amen. Anymore I just start doing the "50% exaggeration" math if its from China. I wish someone would step in. You know there would be people seeking out the old "6hp" shop vacuums if they cracked down on it.

[Brody Goodwine]

I'm not sure I understand the configuration you are proposing. What is this cyclone unit you are planning on using?

I don't know that a cyclone is going to scrub the fines any more effectively than the Thien baffle. The cyclone or Thein baffle will get the bigger/heavier stuff to fall out of the air stream, but you're still going to be direct venting a lot of fines, cyclone or not.

This is the cyclone:
http://www.ebay.com/itm/Cyclone-Sepa...item41635ebbf2

I'm just going to hang the "2hp" HF DC motor above it and cut a vent out the wall.

[steven pratt]

Hey Brody,
I'm doing a very similar installation as to what you're planning. I'm going to use a Thien tophat for my separator and exhaust outdoors like you plan to do. I'm using 6" diameter ducting (from Lowes/HD) for everything including the separator, with the exception of the drops which will be 5" diameter with blast gates so I can run one at a time. The main line along the ceiling will be 6" diameter, dead straight, about 12' long.

I wanted to keep the blower around 2hp due to weight (and budget) as I'm installing it in a closet and will have to be able to lift and hold it in place to mount it. I checked out several different dust collectors in this size range and decided on the Grizzly 240v 2hp model. It has a much larger impeller than the HF unit (12.75" vs 10" diameter) and appears to have a true 2hp motor whereas the HF seems to be more around 1.5hp considering the amp draw. I bought the Grizzly on sale for $275 plus $79 freight so it was about double the price of the HF unit but I felt it was well worth it since there's lot of frictional head loss to overcome when you install these things to run in a centralized configuration (not to mention through a separator), and the larger impeller and motor should help in this regard.

The following article breaks down the different 2hp units pretty well:
http://www.portercable.com/uploads/P...Collectors.pdf

Hope this helps.

[Brody Goodwine]

Steven, that post helped a TON. Unforunately it also induced a ton of buyer's remorse since you clearly outdid me on the research of this setup.

Based upon your post i may pick up that Penn State 110/220v unit and wall mount it. I may just pass on the separator altogether since I'm not exactly a high production shop. Run 6" eveywhere with hardly any bends...

[Brody Goodwine]

Still milling this over...

Do any manufacturers sell just the blowers? I'd hate to buy a $400 dc unit just to have them ship the entire thing for me to scrap it.

Any word on experiences necking down a dc to use in place of a shop vac? It would be nice to not need my shop vac in the shop.

[Michael W. Clark]

Brody,
Did you already purchase the cyclone? It looks like a good design, but I doubt you will ever get 500 CFM through it, waay too much pressure drop. It would be good for about 300 CFM, so I would stay with 4" duct if you are going with this cyclone.

You are not going to have much static avaialble for dust pickup. Staying with 4" will be the best you can do. If you neck down to 2.5", you will have very little flow.

What about ducting outside to a container and bring chips and all through the fan? You would have a LOT better flow at the machines.

Mike

Edit: Just saw your question about the fan. I'm not sure about from the DC manufacturers. There are plenty of sources for stand-alon fans. Cincinnati Fan is one good source, Grainger, Mcmaster Carr, etc. Check CL, there are often used bag collectors on there for cheap.

[Jim Neeley]

Any word on experiences necking down a dc to use in place of a shop vac? It would be nice to not need my shop vac in the shop.

Brody,

Unfortunately that's not a good solution. A DC is a high volume, low suction system. A shop vac is a low volume, high suction system.

If you neck down the DC connection you end up with the worst of both worlds:

Low volume & low suction. It will draw air through the hose but performance will not compare with the shop vac.

[Brody Goodwine]

Thanks for explaining Jim. I presume if a DC was higher suction it would require better sealing and therefore more HP for the same diameter wheel?