Shop Sweep with Cyclone

[SteveMaryland]

Since I do all my wood-cutting work on the driveway, my usual dust collection system is the great outdoors. Occasionally however, I need to clean up the driveway, garage and basement. I wanted a rugged, upright, wheeled vac for use on large outdoor ground areas such as garage and driveway.

So for years I have owned a "Shop Sweep" model 405EDI upright-style floor vacuum, made by Shop Vac. This vac is rugged, has a 19" wide intake, and has large 7" wheels. But it also won't stand upright by itself, and the power switch must be held in during operation. Must have been a rushed design effort at ShopVac.

Biggest problem with it however, was its heavy cloth filter bag which dragged on the ground and was uncleanable. I kept the vac but got rid of the old bag*, and the vac sat un-used for years. But I still wanted a decent upright floor vac for outdoor and basement use.

Since these "Dust Deputy" type cyclone cannisters are becoming more used in vac systems, I designed and fabbed the hardware to mount one to the "Shop Sweep" to replace the old bag.* Pictures below.

The cyclone separator is a "NANTONG SUNING SN50T33". I looked at many of these cyclones, but this one was compact enough for the application.
I had to transition from the 3-5/8" OD on the vac to a 2-1/4" OD on the cyclone. For this I CAD-designed a transition duct and had it made by an FEA fabricator (Xometry). $123 total, but free shipping. Costly, but it fit well on the vac, and I could not have home-made a better one.

Cyclone diameter was 2-1/4" OD so I had to find a hose ID of that size. Found it from BISCO-AIR. $36 for 5 feet + $20 shipping (ouch).
From some scrap acrylic, I designed and fabbed (on my Shopsmith of course) a bracket to hold the cyclone to the vac. This bracket will get bopped around, so I think I will make the next one from aluminum. Sooner or later this acrylic bracket will break.

For the cyclone waste bucket, I used a 2-gallon LEAKTITE bucket + lid. Home Depot sells them. I modified the lid to fit the cyclone, and I cut some portions of the lid away to make bucket removal easier.

On the cyclone air-outlet duct, I clamped a small disposable "pool skimmer" cloth bag. These bags are terrific for use on shop vacs and many other filtering tasks.

I put this cyclone-equipped vac to work. Performance was underwhelming. Needs more power for outdoor debris. I did fill the 2-gallon can with sawdust in a short time, so the cyclone itself is not the weak link. But I expected more suction. It will be better than a conventional shop-vac for floor work, but for the amount of dust I create, the old pushbroom + jumbo dustpan still works best.

* no relatives or in-laws were harmed.

[BuckeyeDennis]

Fascinating! Cyclones are typically used on the low-pressure (intake) side of the blower, capturing the large pieces of debris before they can whack the impeller blades. It had never occurred to me that they would also work in reverse on the high-pressure side. But from the perspective of the cyclone itself, it still has an airstream with higher pressure on its radial/tangential port and lower pressure on its axial port, so it’s just fine with that setup.

How does the suction compare to the unmodified vac? I have a hunch that it would be significantly better with a 4” cyclone, but that’s an awful lot of bulk and expense.

[SteveMaryland]

I don't recall the vac ever having very good performance with the original bag. I also expected the vac would have improved CFM with the cyclone - as long as the transitions and hose length were minimized, which I tried to do. The CG is so off on this vac that it is unpleasant to use. Maybe relocate the cyclone + bucket closer to the motor, or add a balancing weight. Still not enough power, but how much power is enough?

[JPG]

Mount the cyclone/bucket on top of the motor?

[edma194]

Just brilliant. The kind of innovation I love to see. Tools can be functional and just as fun as Legos and Erector Sets to make things out of too.

The bag on top is an interesting approach. Doesn't look like it will impede air flow much, but a vertical pipe extending a ways out of the top of the cyclone unit might help enhance the vortex in the unit. Or not, but if you have a spare piece of pipe would be easy to check out and see.

[larryhrockisland]

Would air flow increase if you hard piped full sized from the vac and used your reducer right at the cyclone? I haven’t seen that model shop vac before, reminds me of a leaf vac.
https://youtu.be/OlLljP49Hns?si=dLqzB6f_v0Di6U1s
Found a video, seems like it has good suction, loud though.

[SteveMaryland]

Thanks for posting the video. I did not know of this model. Looks like a higher-power version with the same front end nozzle. Still has that old bag, but at least it does have a real on-off switch. Still has that stupid kickstand and does not stand upright by itself. Neither model is still on the market. I think a well-designed unit with enough power would fill a real need, which is for a rugged wide-area upright vac with cyclone and large capacity waste can, easily emptied.

I do not think re-locating the constriction would help. The best thing is to make the constriction gradual - or get a larger cyclone that matches the vac port.

[edma194]

The best thing is to make the constriction gradual - or get a larger cyclone that matches the vac port.

Just hard piping instead of that corrugated hose will improve air flow. I'm sure you had that in mind after improving the unit. The larger cyclone to match the vac port diameter would be a good idea. It will be a larger and heavier stack with a reasonable sized bucket under the larger cyclone unit.

I'm going to suggest detaching the cyclone when you use it outdoors. Getting scarred up from rocks and sticky stuff will be bad for the cyclone. Maybe you can put a removable fitting near the cyclone intake and attach the old bag* there for outdoor use.

*No offense to any of your relatives intended.

[SteveMaryland]

Should have watched these YT videos before. First video develops the basic idea of attaching a floor nozzle onto a conventional cannister-type vac:

https://www.youtube.com/watch?v=50TNlVJKRmw

Second video refines the first design and incorporates many improvements:

https://www.youtube.com/watch?v=AScCJaEo_oE

Third video is from someone else, and he shows how to make a cyclone from two bigbox buckets:

https://www.youtube.com/watch?v=1WnitgYFnE0

Hands down, these three videos define a much better approach (than mine) to a large area floor vac. I am sure even further improvement is possible.

Why no commercial cannister vac mfgr has yet to offer this capability is a mystery.