J. Phil Thien's Projects

Help!!

I am still getting a lot of bypass with fine sanding dust and some with regular chips and sawdust. I recall comments about the diameter of a separator affecting velocity, which in turn affects separation.

I built my separator like most others have, using a 30 gallon trash can as a catch container, so the diameter of the separator is dictated by the diameter of said container. Because my dc is larger than most people on this site have indicated, I am beginning to question if I need to change the deminsions of my separator to slow down the spin of air. I was watching it yesterday while my wife was feeding some stock for me and I noticed that it is still sucking fine dust back up through the slot from the container below. I have caulked all air leaks that I could find. At Phil's suggestion, I even caulked the trash can which made a huge improvement.

My question is; would it help to enlarge the depth of the separator and be able to lower the outlet pipe a little more? I can also enlarge the diameter and build a funnel to a different type of catch container if that may help.

Or, am I just expecting too much and need to just leave well enough alone?

Thanks for your input.

Raymond

Galerdude:

Hope these pictures help out. The cone on top is pop riveted on, don't know if it contains a bearing or not. As smooth as it turns, I suspect it does.The shaft is about 1/2" square with the bottom being round where it goes through the bottom brace. The brace does not support the shaft, it just keeps the alignment straight. The flappers are approximately 24 gauge flat metal bolted to the square shaft. They stop about 1" from the pleats of the filter and have a piece of approximately 1/8" thick rubber bolted to the plate. The rubber piece is actually sandwiched between 2 pieces of metal. The main plate and a piece about 1" wide on the back for support. The rubber piece extends about 1/2 way into the pleats. Hope this helps. If you have anymore questions fire away. If you would like more detailed pictures tell me what specifically you need.

I am not sure how much the dust shows up at the bottom of the filter but this is what I have been fighting. These filters were cleaned after I tried the internal baffle (that didn't work as well as the external tophat design).

I built a cabinet for the wifes sewing room. I used about 30 bd ft of pine, ripping, routing and drum sanding and this is what was in the filter.

Before I removed this filter for these pictures I ran the flappers each direction about 5-6 times. This is the "weak" filter and still has this much dust in it. There is probably another 2 cups of dust on the cone below the filter mount. As stated this is the "weak" filter, the other one fills up faster and seems to collect more dust. On a 2 filter/catch bag setup it seems 1 side is "strong" and 1 side is "weak" for lack of a better discription.

Any ideas why this much bypass please let me know. I am just using it and keeping an eye on efficiency of the separator for now. Trying to figure out what I have done wrong.

Thanks,

Raymond

Since my loss of suction appears to be because of the pre-separator, I decided to do the baffle in the dc rings thing.

I tore apart my dc today. Cleaned the filters, installed the baffles and reinstalled the catch containers and filters. I sucked up about 15-17 gallons of mixed saw dust and chips. The fine dust is what came out of the filters after using the drum-sander for about 2 hours straight. Lots of fine dust. Probably about 1/3 rd fine dust to 2/3 rds chips in this test today. I never dropped the suction line into the bucket of dust. I kept it moving about 2" above the level of the dust in the can.

I cleaned 1 filter after my test, (ran the flappers around 5-6 turns 1 way then 5-6 turns the other direction.) There was probably between 1 1/2 - 2 cups of fine dust from the 1 filter.(sitting on the cone, don't know how much went in the container)

I wanted to see how much difference the outlet pipes will make. I only have 4" between the baffle and the lower edge of the cone in the dc ring. I have made some reducer rings to hold the outlet pipes and will install them tomorrow. My thought is to split the difference of the space. 2". I know that Phil says to insert the outlet pipe 1/2 the diameter but with only 4", I don't think that would leave enough room if I insert it 3". The outlet in the cone is 9 1/4". I have 6" pipe to make the outlet pipes. Will this be too much restriction or not? I know I am only pulling air in through a 6" line and this will be 2 6" outlet pipes, 1 in each filter. Just not sure what the outcome will be. Time will tell.

I hope these pictures will help explain what I am trying to describe.

Any thoughts or suggestions will be appreciated.

Raymond

Surgery went well. Getting flexability and grip back already. Stitches out next week.

I have caulked all seams in my tophat, except for the outlet tube. Will be caulking the seams on my collection can today. Thanks Phil, never thought about the possibility of the can leaking.

Now for my question: is it beneficial/detrimental to have the outlet pipe larger than the inlet? Kind of like a cyclone. 6" inlet, 8" outlet. My dc has an 8" inlet so was wondering if it would help to utilize it to it's full potential. I do not remember this being discussed in the past, maybe it was and I overlooked it.

I have devised a plan about a stand for the tophat to set on and the collection can to attach under and make it a lot easier to remove for dumping. Hopefully I can get started on this design/build next week. Will keep y'all posted.

Looking forward to responses about the inlet/outlet idea before I start back together with my system.

Thank you

Raymond

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

Just saw a new overblade safety guard with dust collection. It is in the testing/developement stage and waiting on a patent. (Phil, you know what a hassle that is).

The web site is www.whirlwindtools.com. Looks very promising. It has a contact strip on the bottom edge of the guard the stops the blade if touched by your hand. It uses an electrical force instead of a brake that locks and drops. You don't ruin a blade and you have no cartridge to replace, just reset and restart your saw. It also has some LED lighting over the blade. The good thing is it is a retrofit setup, you don't have to buy a new saw for the safety feature. Hope it comes on the market so we can check it out.

I bet sawstop throws a fit but in my opinion it is enough different operation that there shouldn't be a problem. If I remember correctly, sawstop was originally a retro but no saw companies jumped on the bandwagon so sawstop made their own saw.

This may not be the correct forum for this info, but thought I would put it out there for all of you.

Raymond

I hope these pictures come through.

Thought I had a new idea for a tophat but after looking through older posts, I find the sandwich idea already done. Sorry, had no plans on stealing someones idea. It turned out ok. Seems to work well except I have a little more bypass. May need to play with the outlet a little. Removed all but one of the sharp 90 degree ells. Have an idea to eliminate it also.Will have to give it a try, later. Let me know what you think.

Phil, you were the first to mention the hard 90 degree ells that I had in my system. Several more commented later. I admit I am hardheaded and just couldn't completely wrap my head around the whole concept. My thoughts were something like, it stays the same diameter so what is the big deal.

I just got the Oct. issue of Wood magazine and it has an analogy for ductwork that I can fully understand. First, let me qualify this by saying I was raised in the country in southern Okla and learned to drive on narrow gravel roads.

This article compares a gravel road with rough/rubboard surface and sharp corners to a freeway with a relatively smooth surface and long sweeping curves so you can maintain a high rate of speed. On the gravel road, you have to go slower because it is rough and you have to slow way down to make a turn so you don't roll your vehicle. This visual really opened my eyes to the problems I was facing.

With all that said, I have almost completed my first major overhaul. I have reduced all but 1 of the sharp 90's, have built a tophat separator and am starting to replace my ductwork with 6". I have enough material to re-do about 1/2 of my setup and will have to run with that a little while until I can get more duct.

I tested the original setup vs the tophat after I changed the 90's and in my opinion the tophat has noticeably more suction than the original separator, all other things being the same.

Will post some pictures of the changes next week when I have completed what I can at this time.

Thank you,

Raymond

Don't know what happened but the pictures went through. Machine is way smarter than me. That is a good thing.

No pictures from me tonight. Your site says 1920 kb max, yet it will not take pictures even after I downsize them to 134 kb, what gives?

Let me try this again. I have a Powermatic 1900 dc, I got tired of hearing the knots banging through the impeller when planing pine so started looking at the super dust deputy from Onieda. I then ran across your site and decided to try your design. I had 3, 4" main lines running through my shop. I brought these into an accumulator, then a 6" line to the separator and a 6" line into the dc. It seems that I lost some suction with this setup. My question is this, do you think I would be better off to remove the accumulator and bring the 4" lines into a couple of 6" wyes then into a single 6" line into the separator then a 6" line into the dc? If my pictures come through, I think this will all make sense. Thank you for the design (works great) and for any help/info you may be able to supply. (file too large, pictures to follow)