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Disappointed with my Onieda Super Dust deputy

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Forum topic by Mr Jones posted 06-26-2018 01:11 AM 2833 views 0 times favorited 23 replies Add to Favorites Watch
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Mr Jones

13 posts in 2474 days


06-26-2018 01:11 AM

Hey guys,

Just wanted to get your input on a dust collection issue I’ve been loosing sleep over.

At the moment I have a 3hp motor, 14” impeller hooked up to a Super Dust Deputy.
This is the older model where the inlet is an annoying 5” and the outlet is 6”.

I Ran the setup without filters tonight, to see how well the cyclone separates dust… and it’s terrible! With the amount of fine dust I had sprayed around the shop I would EASILY clog canister filters in no time!

Clogging bagged filters is one thing – you can shake them out and clean them… but canister filters are on a different level of pain. Especially when they are expensive Wynn Filters at $300 a piece!

Frankly i’m very disappointing in the separation. I suspect building a Thein baffle would do about the same as this unit does.

Few idea’s as to why the separation is so bad.

1) 5” inlet limits amount of air coming in. Perhaps even my 3hp can’t get enough air through that 5” inlet. No way to fix this

2) inadequate Cyclone design – seems to be too short based on Bill pentz design and tne NEW Super Dust Deputy XL.

Purchasing a clear view way out of the budget and I only really would use this collector on my planer and joiner which are mainly large chips. I mean if i’m going to be clogging filters frequently with a 3hp setup. Why bother with a cyclone and pleaded canister set up.

So many people rave about how little makes it past the cyclone when it’s connected between the tool and the dust collector. But nobody talks about all the junk that’s probably stuck inside the filter, that never made it to the bottom of the collector bag.

I’ve read posts on this forum where people switch BACK to cloth filters because the pleaded ones clog no matter how good the separation is… Starting to believe pleaded filters are not the way to go…

Thoughts?


23 replies so far

View shipwright's profile

shipwright

8380 posts in 3307 days


#1 posted 06-26-2018 01:22 AM

It may be that you need some back pressure from the filter/bag. I’ve never run one with just the cyclone. I know that my SDD on my Harbor Freight DC works flawlessly and I think I may never have to clean or replace my filter again.

-- Paul M ..............the early bird may get the worm but it’s the second mouse that gets the cheese! http://thecanadianschooloffrenchmarquetry.com/

View Rayne's profile

Rayne

1228 posts in 2048 days


#2 posted 06-26-2018 01:33 AM

I agree with shipwright. You probably need the back pressure. Also make sure there are no air leaks around SDD; that’ll also interfere with the cyclone effect to get all the dust into the bin. The hose connecting to the bin could also be a little too long. The SSD works by creating the cyclone effect to shove the dust down into the bin but with your setup, there doesn’t seem to be much room to create that effect before the suction from your DC grabs hold of the dust. Just some thoughts to consider or try. Mine has also been very effective with very little going into the filter thus far.

View Mr Jones's profile

Mr Jones

13 posts in 2474 days


#3 posted 06-26-2018 01:43 AM


It may be that you need some back pressure from the filter/bag. I’ve never run one with just the cyclone. I know that my SDD on my Harbor Freight DC works flawlessly and I think I may never have to clean or replace my filter again.

- shipwright

Shipwright, I never intended to run it without any filter as i always planned to recycle the air back into the shop. However in regards to back pressure, the filter would certainly add some. I always assumed the ideal ratio was to match the cfm rating of the filters to the blower to eliminate as much back pressure as possible?


I agree with shipwright. You probably need the back pressure. Also make sure there are no air leaks around SDD; that ll also interfere with the cyclone effect to get all the dust into the bin. The hose connecting to the bin could also be a little too long. The SSD works by creating the cyclone effect to shove the dust down into the bin but with your setup, there doesn t seem to be much room to create that effect before the suction from your DC grabs hold of the dust. Just some thoughts to consider or try. Mine has also been very effective with very little going into the filter thus far.

- Rayne

I made the hose connecting to the bin long because i wanted to have the bin on the floor and the collector as high as possible. Perhaps i can make a shelf to bring the bin closer towards the cyclone.

Thanks for the suggestions guys!

View pintodeluxe's profile

pintodeluxe

5986 posts in 3322 days


#4 posted 06-26-2018 02:07 AM

I’ve always been surprised when people get those small cyclones to work right. I have a Tempest cyclone that Penn State used to sell. It looks huge compared to a portable cyclone. I get phenomenal separation with no chips or dust reaching the filter. When I check the cleanout in the pleased filter, it looks like it needs to be dusted with a Swiffer. That’s it.

Once you figure out how to improve separation, switching to hard piping will be the next step. Having that much flex pipe will destroy your useable suction. It makes a huge difference.

Good luck with your DC issue.

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

View Redoak49's profile

Redoak49

4183 posts in 2497 days


#5 posted 06-26-2018 11:09 AM

I suspect something wrong in your set up and maybe the lack of back pressure. There are too many people who have very good results to think it is a problem with the dust deputy.

View Robert's profile

Robert

3537 posts in 1989 days


#6 posted 06-26-2018 02:49 PM

I run a SDD with a 1 1/2HP blower. Its exhausted out side maybe that’s the diff but it works just fine.

I would replace all that flex with rigid ducts. You can use a 5×6 reducer to transition to duct work.

-- Everything is a prototype thats why its one of a kind!!

View pontic's profile

pontic

697 posts in 1117 days


#7 posted 06-26-2018 02:59 PM

bernoulli effect with the 5”to 6” diameters. Creates a decrease in pressure at the 5” side and an increase in pressure at the 6” side. sucking more into that tube and less into the cyclone pot. Fine dust will react more to this increase in outlet pressure. Put a 1” venturi neck on the 6” and see if that works.

-- Illigitimii non carburundum sum

View Ocelot's profile

Ocelot

2356 posts in 3147 days


#8 posted 06-26-2018 04:24 PM

The connection between the bottom end of the cone and the collection barrel has to be absolutely air tight. Any leak there will suck in air and prevent the chips from falling under the force of gravity. I suspect that is where your problem is.

With your setup, you have at least three connections to seal.
1) The rim of the barrel to the lid.
2) Your down hose to the port in the lid of the barrel.
3) The SDD to the down hose.

There has to be no air at all being sucked into the bottom of the cyclone or it won’t work.

For a test, try putting some suds all over those connections and see if it’s getting sucked into the joint.

Disclaimer : I say all that from stuff I read. My SDD is not installed yet.

-Paul

View johnstoneb's profile

johnstoneb

3129 posts in 2681 days


#9 posted 06-26-2018 04:32 PM

What Ocelot said.

-- Bruce, Boise, ID

View EarlS's profile

EarlS

3091 posts in 2857 days


#10 posted 06-26-2018 05:12 PM

From Wiki -

A high speed rotating (air)flow is established within a cylindrical or conical container called a cyclone. Air flows in a helical pattern, beginning at the top (wide end) of the cyclone and ending at the bottom (narrow) end before exiting the cyclone in a straight stream through the center of the cyclone and out the top. Larger (denser) particles in the rotating stream have too much inertia to follow the tight curve of the stream, and thus strike the outside wall, then fall to the bottom of the cyclone where they can be removed. In a conical system, as the rotating flow moves towards the narrow end of the cyclone, the rotational radius of the stream is reduced, thus separating smaller and smaller particles. The cyclone geometry, together with volumetric flow rate, defines the cut point of the cyclone. This is the size of particle that will be removed from the stream with a 50% efficiency. Particles larger than the cut point will be removed with a greater efficiency, and smaller particles with a lower efficiency as they separate with more difficulty or can be subject to re-entrainment when the air vortex reverses direction to move in direction of the outlet.

For anyone that is interested in the theory and math, there is a section that goes into the math of cyclonic separation.

So what does this mean? Others have suggested you need some back pressure. Why? That will force the system to a lower flow rate since the blower curve goes from lower flow and higher differential pressure to higher flow and low differential pressure. Why does this matter? Low differential pressure and high flow means higher velocity which means more of the dust is being held up in the airstream rather than hitting the walls of the cyclone and falling out. It’s all about dissipating energy and slowing the particles down in the cyclone so they fall out of the air stream.

The go to source is Bill Pentz, if you have time to read through his site.

-- Earl "I'm a pessamist - generally that increases the chance that things will turn out better than expected"

View Fred Hargis's profile

Fred Hargis

5747 posts in 3002 days


#11 posted 06-26-2018 06:08 PM

The first thing I would check is the air tightness of the drum and connections, like they said above…any leak will cause the dust to go right to the filter. I’ve used smoke (a cigar) in the past, but didn’t like waiting 3 days for the shop to air out…so now I use a downy feather from a duck and move it around all the joints. Any leak will draw to fine veins into the fitting.

-- Our village hasn't lost it's idiot, he was elected to congress.

View fivecodys's profile

fivecodys

1487 posts in 2145 days


#12 posted 06-26-2018 11:36 PM


I run a SDD with a 1 1/2HP blower. Its exhausted out side maybe that s the diff but it works just fine.

I would replace all that flex with rigid ducts. You can use a 5×6 reducer to transition to duct work.

- rwe2156

Same here.
No issues to date.
Here is what I did. http://lumberjocks.com/topics/256729

-- When you leave your shop for the night, make sure you can always count to 10.

View Mr Jones's profile

Mr Jones

13 posts in 2474 days


#13 posted 06-27-2018 01:41 AM



I run a SDD with a 1 1/2HP blower. Its exhausted out side maybe that s the diff but it works just fine.

I would replace all that flex with rigid ducts. You can use a 5×6 reducer to transition to duct work.

- rwe2156

I can simply exhaust the material outside and get the similar results, but i want the exhaust air going into a filter.
With the 3hp blower, there’s more than sufficient suction power and while i can replace the flex to obtain more cmf that isn’t exactly solving my separation issue right?


I ve always been surprised when people get those small cyclones to work right. I have a Tempest cyclone that Penn State used to sell. It looks huge compared to a portable cyclone. I get phenomenal separation with no chips or dust reaching the filter. When I check the cleanout in the pleased filter, it looks like it needs to be dusted with a Swiffer. That s it.

Once you figure out how to improve separation, switching to hard piping will be the next step. Having that much flex pipe will destroy your useable suction. It makes a huge difference.

Good luck with your DC issue.

- pintodeluxe

The Penn State Cyclone seems to be proportionally sized. It looks closer to the tall and narrow pentz design! I remember when it was on sale – price was very decent.


The connection between the bottom end of the cone and the collection barrel has to be absolutely air tight. Any leak there will suck in air and prevent the chips from falling under the force of gravity. I suspect that is where your problem is.

With your setup, you have at least three connections to seal.
1) The rim of the barrel to the lid.
2) Your down hose to the port in the lid of the barrel.
3) The SDD to the down hose.

There has to be no air at all being sucked into the bottom of the cyclone or it won t work.

For a test, try putting some suds all over those connections and see if it s getting sucked into the joint.

Disclaimer : I say all that from stuff I read. My SDD is not installed yet.

-Paul

Rim at the barrel is air tight – It’s a Food grade metal drum with a silicon gasket and a locking clamp
The rest have been checked for leaks and I’ve sealed everything with layers of hvac tape. But I will could check again

- Ocelot


So what does this mean? Others have suggested you need some back pressure. Why? That will force the system to a lower flow rate since the blower curve goes from lower flow and higher differential pressure to higher flow and low differential pressure. Why does this matter? Low differential pressure and high flow means higher velocity which means more of the dust is being held up in the airstream rather than hitting the walls of the cyclone and falling out. It s all about dissipating energy and slowing the particles down in the cyclone so they fall out of the air stream.

- EarlS

I’ll add the filters Shipwright suggested and see how it holds up.

I run a SDD with a 1 1/2HP blower. Its exhausted out side maybe that s the diff but it works just fine.

I would replace all that flex with rigid ducts. You can use a 5×6 reducer to transition to duct work.

- rwe2156

Same here.
No issues to date.
Here is what I did. http://lumberjocks.com/topics/256729

- fivecodys

I read your post. I’d like to avoid the expensive 5” metal ducting from Onieda.
It seems your also venting outside which is an option for me, but i know I’d upset my neighbor’s with the exhaust noise haha!

I honestly feel the problem with this Model of Dust deputy is the 5” inlet. It makes finding anything but flex piping difficult or expensive. I tried finding 5” S&D pipe with no luck (I haven’t found a distributor in Ontario) so i resorted to flex. I could always step up to 6” but that doesn’t make sense when the inlet is 5”

I honestly believe this is why the new model comes with a 6” outlet and 6” inlet and it taller. It must work words better in separation…

View ArtMann's profile

ArtMann

1435 posts in 1325 days


#14 posted 06-27-2018 01:47 AM

I think the people who are talking about too much air velocity are right. My SDD works great with a 1 1/2 horsepower Delta machine. You really need the Super Dust Deputy XL, which has a larger capacity.

View Mr Jones's profile

Mr Jones

13 posts in 2474 days


#15 posted 06-27-2018 02:19 AM



I think the people who are talking about too much air velocity are right. My SDD works great with a 1 1/2 horsepower Delta machine. You really need the Super Dust Deputy XL, which has a larger capacity.

- ArtMann

How would you define works great? are you exhausting into pleaded filters ? How often do you clean them?

I’m leaning towards the dust deputy xl, But i really don’t want to spend another $300 on an Oneida product to have it disappoint me.

I feel if i’m going to buy another cyclone, i might as well buy a clear vue and be done with it

showing 1 through 15 of 23 replies

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