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Thread: Performance Curve for Oneida Super Dust Gorilla 5 HP

  1. #16
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    This is great information Larry! Very interesting data. Quick question though, how do you take the measurements at all this individual points? Did you use the Dwyer 471 and drill holes into the ducting at those points to insert the probe or did you take measurements as you were assembling the ducting?
    If at first you don't succeed, redefine success!

  2. #17
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    All the measurements in my shop were taken at one point near where the duct comes into my shop. Then, I just open the blast gate of interest. I drilled a 7/16" hole in the bottom of the duct and used the same holder for the probe. I measured the flow at 6 positions across the duct and averaged them. The connection for the static pressure measurements were also taken at just one place nearby where the flow measurements were taken.

  3. #18
    How do your machines work where you have 4" connections? I changed the 4" on my edge sander to 6", as it threw dust everywhere. Even with the 6" it could be improved.

  4. #19
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    I would guess that an edge sander might be the most difficult tool to collect dust from. The belt running at high speed and reversing direction around the rollers would naturally throw dust everywhere. Likely, the only real improvement would be better shrouding and more powerful air flow. You are going in the right direction by upping your duct to 6". The reason Bill Pentz preaches using large and powerful blowers and large ducting is to create that "bubble" of entrained air around the tool to capture the fine dust. My Performax drum sander has a well fitted shroud and it's still the worst offender in my shop. Unfortunately, it came from the manufacturer with only a 4" port in the shroud. I initially used a 4" to 6" adapter to hook up to my 6" duct, but that really did little to improve things, the 4" port was still choking the air flow into the 6" duct. The real improvement will be when I do what I should have from the start and enlarge the opening to take the 6" ducting and do away with the adapter.

  5. #20
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    I am a little confused as to how with a restriction of 260 CFM at the entrance the volume of air can increase to 1360 at the DC ingress? Does this mean more air is being allowed in somewhere along the run? Are we confusing 'air speed' with 'volume'? Obviously I know little about this or I would probably figure it out all on my lonesome ;-)

    P.s. it is not your responsibility to teach me physics so please feel free to just tell me to go look it up.
    Last edited by glenn bradley; 07-25-2016 at 12:02 PM.
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  6. #21
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    Quote Originally Posted by glenn bradley View Post
    I am a little confused as to how with a restriction of 260 CFM at the entrance the volume of air can increase to 1360 at the DC ingress? Does this mean more air is being allowed in somewhere along the run? Are we confusing 'air speed' with 'volume'? Obviously I know little about this or I would probably figure it out all on my lonesome ;-)

    P.s. it is not your responsibility to teach me physics so please feel free to just tell me to go look it up.
    That was actually part of the reason I asked my questions above (post #3). If the measurements were made at the open end of ducting at each given point then it makes sense that the ducting is just acting like an inline resistor in an electrical circuit, restricting flow along its path and reducing the volume of air (CFM) flowing through the open in of the ducting.


    I also had a question on something in this image:



    What happened at the end of that run right after the elbow that caused the CFM to drop from 600 to 260?! Isnt that just a short union connector from the elbow to the back of the DW735 planer?
    If at first you don't succeed, redefine success!

  7. #22
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    Great thread.

    I run 6" pipe to machines that only accept 4" DC .. and change to 4" right at the port. I have an edge sander for instance which actually has amazingly good dust collection, but it has 4" plumbing built right inside the cabinet. No point in cutting a bigger hole and I'm not re-plumbing it because it works so well already. 6" wouldn't fit anyway..

    I actually think in some cases, machines only really need 750 cfm to do a good job.

  8. #23
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    All of the measurements were made at one point near the start of the 6" duct a couple of feet after the 8" to 6" reducer. The measurements represent what was the air flow with that particular area open.

    For example, I measured 1360 cfm with the wye and no gate. I then measured the flow with the 6" gate and it reduced the flow slightly. Then I measured it with the 6" to 4" reducer and resulted in a reduction to flow to 746 cfm. All of the measurements were done this way and most of the conditions were repeated to try to avoid mistakes.

    The addition of the elbow reduced the flow from 722 to 600 cfm. Is this typical? I do not know but that is what I measured. I welcome anyone to present their data and what they actually measured. There is very little actual data and I present this as what I found. It would be great for others to do similar work so we have a comparison.

    The 260 cfm is meant to represent the flow when connected to the DW735 . The planer greatly restricts the air flow.

    It seems that there is some confusion about my diagrams. Sorry about that but I tried a number of ways to show the data and this worked for me. A large table is boring and also can be confusing. I welcome suggestions to try to make the data easier to understand.

    I also tried measuring with a hand held anemometer. The data was inconsistent and varied so much based upon exactly where you held it. I did not feel confident enough to present the data.

    For my current machines, the 4" ports seem adequate. If I added a drum sander, I would probably use a larger port.
    Last edited by Larry Frank; 07-25-2016 at 8:32 PM. Reason: Added info

  9. #24
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    Dust Collector Results - Final Post

    I have tried to present as much data as possible on my testing of my dust collector and duct system. I hope that some have found it useful but it does seem to have raised a number of questions.

    My final bit of data is the graph below. This represents all of the data that I have accumulated during testing. It shows the flow in CFM versus the Static Pressure. The data was fitted to a polynomial in Excel and shows a pretty good fit with an R-squared of 0.97. Now, what is the use of this graph? The use for me is that it represents my system and its characteristics. In the future, if I want to change the duct or something else, I do not want to have to measure the flows. Instead, I can make a simple static pressure measurement with my homemade u-shaped water manometer. With that, I can go to my graph, and find the flow that corresponds to that static pressure.

    All Data.jpg

  10. #25
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    Larry,

    Your data is clear and I think your testing is valid. Certainly the best real world example I've seen published on line.

    I will admit that there are a few machines that might work OK with dust collection from a 4" port, but not many, and the dust collection will be just so-so, nothing like it could be with larger ports and ducting. I was resistant to the 6" duct myself, because I thought it was unwieldy compared to the 4". A conversation with Dick Wynn of Wynn Environmental convinced me to try the larger hose.

    I have an installation where a small table saw has a 2 1/2" shroud around the blade. I knew that by itself, that was clearly inadequate for any decent dust collection, so I added a 4" port in a hopper under the saw. When I did the installation, I put a blast gate on the 4" port. I made a manifold that combines output from the 4" port and the 2 1/2" blade shroud to the 6" ducting. Still not as good as one 6" port, but better than either one alone. I tried closing and opening the blast gate with the DC running and it was clear from the sound and reduction in air flow through the zero clearance insert that the DC was not moving nearly as much air when the blast gate was even partially closed. Essentially, by using the stock 4" port with 6" ducting, you are placing a permanent, partially-closed blast gate at the start of your ducting. That was the night I started figuring out how to increase the port size on all my machines. Now, they all have 6" ports except for the drum sander. When it cools later in the fall and I can get into my garage again, the drum sander will get its 6" port. I think Larry's testing clearly bears this argument out.

  11. #26
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    I would agree that opening the port size on some machines will result in better dust collection. The question is how much and does it make a big enough difference to justify the work.

    I went back to look at James Gunning Dust Collector in his posts. In the latest post I could find, he is using a 1 HP Penn State blower with a 10" impeller. As I understand it, with the Super Dust Deputy that he is using, he has made an adapter to increase the size of port from 5" to 6" at the SDD. He is measuring with an anemometer about 500 cfm at the end of his 6" duct. With his dust collector, increasing the hose size helps as he has limited static pressure from the dust collector. The real question is what is the air flow with the saw connected. I think that it would be interesting to everyone to obtain accurate measurements on all sizes and types of dust collectors. This helps people make good decisions. An easy thing to do on any dust collector is to measure static pressure with various conditions. This can be easily done with a home made water manometer. I did some testing with mine and compared the results to a digital manometer. The results were identical...but the digital one was easier to use.

    In my case, I am running a 5 HP motor with a much larger impeller. With a 6" blast gate, I see 1345 CFM, and at the 4" connection to my saw 720 CFM and with the saw connected I see 670 CFM. So, is it worth the effort to increase it to a 5" or 6" port. Yes, it will gain some flow but the limitation is most likely on the part saw and how much air can be pulled through it. With the current connections, I do not see any dust coming off the saw. I am all for increasing port size if there is a benefit for me. It comes down to with any system is there a return on investment.

  12. #27
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    Larry,

    I am still using the 1HP Penn State blower. (no luck yet finding a larger 110V blower on CL in my area). I did make an MDF "doughnut" to increase the blower inlet size from 5" to 6". The SDD already has a 6" inlet and the doughnut just mates them together.

    I agree there is likely little benefit to changing your system. You have a large enough blower and duct system and other than possibly replace the flex and use 6" pipe the entire way, you are about as optimized as you could be. As you stated, it does come down to return on investment. I was really thinking more of a guy like me, who has a small shop and is wondering how to go about dust collection to get the most bang for the buck. Looking at your system using a 5HP blower and at the end of your piping be down to 720 CFM from 1600+ should reinforce the idea that using the right duct sizes and layout is needed to get adequate performance out of the smaller DC/cyclones. The "industry standard" 4" ports and pipe really aren't adequate, especially for small DC/cyclones. I have preached the 6" ports and pipe since it will give a real world improvement on a small system like mine.

    As always, we do what works for us. Money, time, space all come into the equation.

  13. #28
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    Larry, if that were my system, it would drive me bonkers wondering what that curve would look like with an impeller sized to max out the HP (amps) with all of the ducts open. I would contact Oneida asking if they had a bigger impeller to try, although you might be limited by the size of the housing. Very impressed with all of your analytic work by the way. Love the curve fitting to the data.
    Last edited by Ole Anderson; 07-26-2016 at 12:47 PM.
    NOW you tell me...

  14. #29
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    I've merged three related threads specific to the Oneida unit into one for better reference over time. Very good information!

    Jim
    Forum Moderator

  15. #30
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    It should also be noted that each cyclone is designed to separate most efficiently within a certain cfm or velocity range. Swapping impellers will likely require adding filter media and may require a different cyclone. Dave

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