OK. My redo is complete. All new 6", 24 gauge stove pipe. All but 1 sharp 90 replaced with 30 and 60 degree ells. Ductwork runs down to 6" wyes and blast gates then to 4" flex to the tool ports. I am thinking of changing some of those to 6" also, where possible.
Now for my delimma. I thought I lost a lot of suction with the separator so I built a simple manometer from instructions found on the internet. Without the separator I was pulling 10" of suction. With the separator suction fell to 6". I also noticed that when I was using only 1 - 4" gate that I was pulling dust up out of the collection can. I could partially open the adjacent gate and would stop pulling dust out of the can but the "working gate" lost a lot of suction. I don't know if it was actually bypassing or just pulling the dust into the tophat and just swirling around. Ran out of time. Hopefully tomorrow I can determine if it was bypassing or not.
Before I found the plans for the Thien Baffle, I had been looking at the super dust deputy from Onieda. I also saw a cyclone modification on ebay from a guy in New York. My question is this, is this type of suction loss normal for any type of separator or have I done something wrong in the way I built my separator?
I do a lot of planing and sanding rough lumber and am getting tired of constantly clogging the filters on my dc so would like to have a separator to cut down on this problem. I just don't know if I have made a boo-boo or if any type of separator will give comparable suction loss.
Any thoughts or suggestions from the readers and/or Phil will be greatly appreciated.
Thank you,
Raymond
Do you have pictures of your separator construction? Or possibly a link to that info?
I, personally, am clueless about any possible suction loss. In my scenario I had used a plastic trash can topper separator (?) for 3 to 4 years with a wynn filter and had totally, well almost totally, plugged my filter. So right after building the Thein TopHat, I thoroughly cleaned the filter and wound up with more suction than I had been used to for quite some time. I was, and have been, ecstatic since then about the performance. Not a very good comparison, I know, but that is my limited experience with the suction scenario.
With yours, that does seem to be a lot of suction loss, so I do hope that it's something that can be remedied. Hopefully, others more experienced will post their clues and suggestions on this matter. Do post some pictures or links to your construction, though. I think that would be beneficial.
Thanks,
Gale
Here is a link to a previous thread w/ pics:
http://www.jpthien.com/smf/index.php?topic=533.msg2770#msg2770
A 4" drop seems high, but not surprisingly high given what is going on. I do know that conventional cyclones use large impellers and the manufacturers stress proper ducting because there is a substantial drop through the cyclone.
I'm perplexed by the problem w/ the possible bypass w/ a single 4" port open. I can only imagine there are leaks in the separator somewhere (which could also explain some of the drop you're seeing). So maybe with only a single 4" port open, the blower is finding a leak in the separator somewhere and that is bringing some dust with it. When you open another port, the blower "finds it easier" to bring the air in through that open port instead of the leak. But I'm just guessing at this point.
Perhaps when you have more time you can try wrapping all your seams with some blue painter's tape (clean the dust off first) from the outside, and see if you still have a bypass issue?
Let us know!
Okay, thanks Phil for posting that link; read thru your build.... ::)....you've got determination mister, wow ;). Two quick questions;
- Where are you, in the system, performing the test with the separator hooked up?
- And where in the system are you performing the test with the separator disconnected?
Also, could you post that link for the DIY manometer? That sounds like a fun little thing to do 8).
Thanks,
Gale
Phil: thanks for your response. The cyclone I mentioned is just the body. You can either put a blower on top or connect a single stage dc to it like some of us are doing with your separator design. I will try your suggestion on taping all seams and trying again. (after I complete this project I am doing for the wifes sewing room.) First things first. I will say the separator has cut down on the filter clogging, even with the suction loss I am experiencing. The super dust deputy, you are probably familiar with.
Galerdude: I am doing the test at the same place, trying to keep the test apples for apples. That said, my tests are done at the longest distance from my dc. That is through about 32' of 6" pipe, a 4" blast gate and 15' of 4" flex. This is where I put a portable Delta downdraft table to do hand sanding with a random orbital sander. At the end of the same hard pipe but only 2' of 4" flex I have a Jet 22/44 drum sander. These are my major fines generators.
As far as the manometer, I just typed manometer in my bing search engine and started looking. When I came to this project I decided to give it a try. Not sure as to the accuracy but it is a simple apples for apples test . The easy instructions are: place a scrap of wood vertical ( I used a piece of 1/4" plywood about 15" wide by 24" tall) place a clear tube in a u-shaped loop on this board, add some food coloring to water and pour into the tube until the loop is about 1/2 full. Place a mark ( 0 ) even with the levels of water. Then I measured/marked inch marks up and down from that point. 7 or 8 inches each way is more than enough. I plugged one end of the tube, drilled a hole through a piece of 3/4" plywood and forced the other end of the tube into that. That piece of plywood then is placed over the end of your suction test hose. When it pulls the water up you read both measurements. 1 side goes up 5" the other side goes down 5", this equals 10" suction. At least that is the way I understand it to work. That is how I arrived at my numbers.
Thanks for the input/suggestions. I will try to post some pictures in the next few days, of the redo and the manometer. Maybe someone else will get a kick out of it also.
Tried to add manometer pictures now, hope they come through.
Raymond
Resized these pictures and trying again.
Raymond
Thanks for the pictures and info on the manometer! I gotta try that one.
Just trying to eliminate the obvious so please bear with me......got more questions;
- Did you switch to the metal can and if so, did you put a clear monitoring window in it, also?
- If using a collection can with the window, is the window sealed up tight?
- Concerning the seal of the Thien TopHat to the can; is that a constantly good seal? The reason I ask that is, once after emptying mine, I put it back on cockeyed ....lets just say... we hope that doesn't happen again :-[.
Thanks,
Gale
Galerdude: Yes, I am using a metal collection can. Yes, I put a window in it. When I built it I cut the hole in the can, cut the window 1" larger on all sides, drilled the holes through the window and can, placed a bead of silicone around the hole in the can, bolted on the window squishing out the silicone and then wiped around the inside and outside to complete the seal. I have been un-able to detect any leaks here. The under side of my tophat is made of 3/8" mdf with the hole cut to be a press fit around the top of the can, it rests on the 1/4" mdf that I made the baffle from. I have not noticed a leak in this area but will check again to be sure.
I have read on different posts about the shape of the collection can not being of importance. I have thought of raising the tophat and mounting it on the wall, adding a 4 sided funnel tapering fron 21" down to a 6" connection to the can. Any thoughts on this vs trying to build a round funnel. The 4 sided method will be a lot easier to build but will it be detrimental or no difference. Just curious. Doing this either way will make it easier to empty the can.
Thanks for the questions. The more things to check the better. I know the answer is out there.
Raymond
Raymond, thanks for the info. What a mystery ??? I'm gonna have to put together one of those manometers and test mine now. Could be a few days but I'll post when I know sumpthin'.
Don't know for sure on the shape of the collection can but I've read where it's not supposed to make a difference. Maybe you could make it a 6 sided cone. A little easier than round. Anything you do to make it easier to empty and not sacrifice the separation/suction, would be a huge plus, I'm thinkin' ;)
Thanks,
Gale
Phil: I found some leaks around the edge of the Lexan. Not sure if it is enough to create the problem I am having or not. I will seal it with silicone instead of tape. Easier and should seal it better. Thanks.
Galerdude: The manometer is easy to make and it gave me a more realistic test than just sticking my hand over the flex hose like I was doing. Have fun with it.
I have some pictures of the redo, hope they come through.
I will be having trigger finger surgery on my thumb and three fingers of my rt hand next week so have to try and finish this project for the wife. My separator will be on hold for a few weeks during recovery.
Raymond
Raymond,
Sorry, I don't have time right now to read this thread thoroughly. However, there is a very good thread written about SP loses that I wanted to point you to. You may find that your 4" of sp loss is not out of line depending on how it was measured. Here is the link, read it thoroughly to see if it relates to your situation.
http://www.jpthien.com/smf/index.php?topic=466.0
Also, one other comment. With the power of your system, I would bet a dozen donuts you are getting leaks around the collection can seal. You have two hard surfaces forming that seal, and if your can is like most it has at least one rolled seam that creates a bump on the rim. Do a smoke test. I finally put a rubber gasked in my top hat to make sure it wasn't leaking.
You might also want to caulk the seams of your can. I thought you were still using the plastic one. I've had a couple of metal ones now that leaked quite a bit around the bottom and the side seam. I wouldn't have thought it but in going over them with an incense thingy the smoke got sucked right under and into the can when I was checking the side seam on one of them.
Wow! Nice Shop.
Wish you the speediest recovery possible with your surgery!
Hoping to hook up the manometer permanently in the system. Mine is outside in an attached room so am thinking this would make a nice accessory in case something is amiss. Should have some comparison data for you to ponder over by the time you get back to this.
Thanks,
Gale
Galerdude: Thanks. When I had my left hand done, it was no big deal. Just had to let the incision heal and not break apart. Out of the shop for 2-3 weeks. It will improve my grip though. Can't grip anything with it as it is. Thumb and fingers lock up in the joint and don't want to flex.
Will keep checking back to follow your progress with the manometer..
Raymond
I, too, would like to wish you a speedy recovery! Hope this one goes even better than the last!
Good luck on the surgery Raymond. I used to think trigger finger was some kind of a joke. However, last year I had a bout with my left thumb. A shot took care of it (took about 4 weeks). Unfortunately, it has now returned after about 13 months. I've been putting up with the jerky motion for about a month now. Since I don't have much pain I have put off going back to the doctor, but I guess that is coming. I hope he can fix me up with another shot. I'm not looking forward to surgery. I'm not sure why I'm having the problem with my left thumb. I'm right handed.
Phil: Thank you. I am having the same doctor do it. Should be fine. With all the surgeries I have had it continues to surprise the doctors how quick I recover. The main thing that surprises them is that diabetics are typically not fast healers. They say I heal faster than most non diabetics they treat. I tell them I am just too hardheaded to let it get me down.
Retired2: I also am right handed and the left hand messed up first. Go figure. I also had the cortisone shot in my left thumb, it lasted about 3 weeks. I had that thumb done in July 2009, then in Dec, '09 my 2 middle fingers on the left hand acted up. I told the doctor to not even mess with the shot. Let's fix it. Now my thumb and middle 2 fingers are bothering me, again I told him to fix it, heck with the shot. Since we scheduled the surgery, my rt index finger is acting up. Will probably get him to do it also.
Trigger finger is what they call it. The doctor explained it as the ligaments not sliding properly. He likened it to fishing line getting a knot in it, hanging in the guides. Then popping through and when you reel it back it hangs again then pops through. They go in and slice a small part of the outer section of the ligament so the inner 2 parts can slide as they are supposed to do. No sweat. The irritating part is not being able to bend the thumb or fingers to pick up something without having to force them to bend.
Will continue to lurk about until I can get back in the shop.
Raymond
Raymond, I was excited to let you know I got the Manometer made. As the pix show, it's in plain view when I'm at the CNC. I can't ever hear whether the DC is running or not so this is gonna' work great. My DC and separator sit right on the other side of that wall. Too late to do any testing tonight but should be able to get some data this weekend for you to ponder on. Thanks again for the idea! 8) 8) 8)
Gale
Looks like a very professional build. Mine was very basic but it gave me the info I was looking for. With your dc in another room, your setup will be great as an indicator. First, is it running. Second, it should be a good indicater if you get a plugged line.
Glad I could provide an idea. You capitalized on it, top notch.
Looking forward to see your results.
Raymond
Raymond, got some data for you. Not that it's relevant but I'll explain some conditions that exist pertaining to my system: with the Thien Top Hat in place there's 2' of 4" pipe from the wall to the inlet. Without the separator in the system; the same 2' of 4" pipe plus an HVAC metal 4" to 5" adapter. My motor/impeller sits on top of the separator. I have 2 gates on my 4" system, 1 at the CNC and 1 for my table saw & planer (I switch back and forth).
- # of Gates Open / w/Thien / wo/Thien
- 0 / 7.5" / 7.75"
- 1 / 2.5" / 4.75"
- 2 / 1.75" / 4"
Hope this helps you pursue your "suction loss" situation. Any questions or ..... I'll do what I can.
Thanks,
Gale
Very interesting. Not sure what type of dc you have, how it compares to mine. I have a Powermatic 1900. It would be interesting to see what the comparison is in relation to stated cfm. Mine is supposed to be 1900 cfm at 8" inlet. I have it reduced down to 6". Not sure what that reduces the cfm to. I may have done my test wrong. I had the adapter for the manometer blocking the end of the hose at the very end of my longest line. I noticed you had a fitting in the duct just before it goes through the wall. Not really sure what this does to the test results between your setup and mine but for either, it gives each one of us a solid number to compare to.
The things we big kids do for entertainment.
Raymond
Yeah, I found it interesting also ::). Lotsa' factors, for sure, but here's a couple more facts specific to my system, hope it helps:
- The tubing used for the manometer was 1/2" ID.
- My DC is a 10 year old Harbor Freight advertised at 2HP(?). Don't know the CFM, other owners might.
The main thing being, it seems there is an abnormal amount of suction loss when your Thien separator is hooked up :o. The #'s might have to do with where the tests were done, I dunno. I did find it strange, the variance in numbers with the gates open & closed with the Thien and with out. I'm
not gonna pretend to understand any of that ::).
I'll be monitoring your success in getting this to acceptable levels. If I can get ambitious I might try to perform the test closer to how you did yours just for comparison.
Thanks,
Gale
I do know that I have some leaks in my system but with me testing where I am, those leaks are taken into consideration with either test. If I have time before my surgery I think I will disconnect my ductwork and do the same test right at the inlet to the separator and then at the hose I connect to the the outlet from the separator. That should give a test that only has the separator to be considered. I need to caulk a couple of leaks in my separator first. I haven't caulked them yet because I am toying with a different configuration idea. Didn't want to waste the time if I am going to pursue this other idea. We will see.
Raymond