New Dust collector question

[Dave Sharpe]

So I got the new Grizzly G0440 2hp cyclone all hooked up (boy was that a challenge getting the motor assembly way up in the air onto the loft I built for it - I pulled out my old search and rescue gear and rigged a hauling system and was able to do it, but it wasn't all that easy) For now I'm just using 4" ABS pipe as I'm planning a shop re-arrangement and don't want to spend a bunch of money on metal ductwork until I know just where I want everything to end up. I was fortunate that the previous owner of my place had wired a 220 circuit for a welder and I was able to tie right into that, so no big hassle there. I got it all set up and fired the DC up and proceeded sweeping up the shop - the floor sweeps work well but there wasn't all that much sawdust on the floor(for once). So I grabbed a shop vac and dumped a bunch of sawdust from the tablesaw out on the floor and swept it all in. It cleaned all that up with no problem, but I noticed that most of the sawdust ended up in the collection bag below the filter, with almost nothing in the collection drum below the cyclone itself. Grizzly's customer service was already closed for the weekend, but I noticed in the instructions (yes - I glanced through them) that it says that small sawdust from tablesaws often goes to the filter, whereas larger chips produced by a planer or joiner will end up in the collection barrel. So I ran a few boards through the planer just to check, but still next-to-nothing in the collection barrel. I've never used a cyclone DC before, so I'm wondering if this is normal. It seems like a waste to have a big ol' collection barrel sitting there if everything is going into the filter and then into the plastic bag.....
The only real modification I made is to install the dust collector with the inlet 10' high, which required a shop-made 5' high duct from the cyclone down to the collection barrel. I don't think this should affect the distribution of the dust though. Any ideas?

Dave

[Joe Jensen]

Dave, first of all, you live in an amazing place. High on my list of potential retirement locations :D

I only have experience with Oneida. With my cyclone, almost nothing gets past the cyclone, even sanding dust, unless I overfill the barrel :mad:

Something must be wrong. I can't image a cyclone working the way you say. Can you say more about how it's hooked up? Is there sufficient airflow with your test? That's all I can think of...joe

[John Jendro]

Not an expert here, but I think you have a leak between your collection barrel and the bottom of your cyclone. Either your modification is leaking or the top of your barrel isn't tight.

John

[Dave Sharpe]

Thanks Joe - Yes Whidbey Island is a great place and a wonderful place to retire (or semi-retire as I have) The last few days have been especially beautiful, with temps up to the -gasp- 80's. OK, that's not much where you live, but it's a downright heat wave here.... From the hill where I live we can look out across upper Puget Sound and see the Olympic mountains - just plain purty!
Back to the matter at hand - dust collection. I think you may have the right idea about not enough airflow. As I mentioned, I'm using just 4" ABS pipe for now, and the DC has a 7" inlet port. (if I remember my grade-school math that reduces from about 38 square inches to just 13) I put in a 7" - 4" reducer right at the inlet port, and then ran 4" ABS around the shop. I'm thinking that may be too small and the airflow is restricted too much to allow the cyclone to separate the dust properly. I did notice that when I first tested the DC without the collection barrel attached at the bottom, air seemed to be flowing INTO the bottom of the cyclone when I held my hand there.
So, any suggestions for remedying this problem short of spending another fortune to put in larger, heavier ductwork? I'll get there eventually but as I already posted, my tools aren't all in their final locations yet

Dave

[David Freed]

Not an expert here, but I think you have a leak between your collection barrel and the bottom of your cyclone. Either your modification is leaking or the top of your barrel isn't tight.

John

This was my first thought too.

I have a Clearvue, and we will get maybe 2 or 3 cupfuls of saw dust to the filter after working up a couple thousand feet of lumber if it is sealed right. That includes planer, gangrip saw, moulder, and sander.

I deal with a large volume of dust, so I hooked up a blower to the bottom of my cyclone that can just barely overcome the suction from it. The net result is the sawdust goes out into my silage wagon, and much of the heated or cooled air stays in the shop.

There has been the rare occasion when we started the cyclone without the blower (oops!). It takes just a few seconds to stop up the filter (and about 10 minutes to clean it out).

[Rob Will]

Dave,
Without a doubt, you need more volume than a 4" pipe can deliver to make a cyclone work. Also, you probably have a leak below the cyclone.

If possible, when you set up the permanent piping, try to get a straight uninterupted run of pipe the same diameter as the cyclone inlet for several feet before it hits the cyclone.

I have an Onieda system with a 10" inlet and 10 feet of 10" spiral pipe just before the cyclone. We get virtually nothing in the filters.

Rob

[Burt Alcantara]

Another vote for a leak. Wave lit incense around the fittings and see if you get an reaction. Also, check the rotation of the impeller. Perhaps, the motor was wired backwards, but I'm not sure if it would make a difference.

When I first set my ClearVue up I had the same problem. I traced the problem to my trash bin. Was not sealed enough so everything ended up in the filter drawer.

Burt

[Dave Sharpe]

Thanks to all of you who mentioned leakage below the cyclone, I solved the problem. I was using thin sheet-metal ductwork to connect the cyclone to the collection barrel, and it was collapsing partially under the suction. In fact, when I inadvertently closed ALL the blast gates, it sucked flatter'n a pancake. So I tried stacking the collector drum onto a wooden case that raised it up high enough to connect directly to the cyclone, and it works like a charm! I guess I thought there would be no suction at the bottom of the cyclone - kinda silly in retrospect.....
So now I need to find a way to connect the drum to the cyclone from 5'4"" away.. I suspect that that long a piece of flex hose would collapse also, so perhaps some really strong rigid duct material? It comes in 5' lengths - anyone have experience cutting this stuff? While I'm at it, I guess I'll spend a few bucks and get some larger duct to at least start my run with.

Thanks for all the advice! You guys rock!
Dave

[David Freed]

So now I need to find a way to connect the drum to the cyclone from 5'4"" away.. I suspect that that long a piece of flex hose would collapse also

If you buy a good quality flex hose it won't collapse. The kind I use is wire reinforced. It can be a little pricey, but with flex hose, you get what you pay for.

[Ken Fitzgerald]

Thanks to all of you who mentioned leakage below the cyclone, I solved the problem. I was using thin sheet-metal ductwork to connect the cyclone to the collection barrel, and it was collapsing partially under the suction. In fact, when I inadvertently closed ALL the blast gates, it sucked flatter'n a pancake. So I tried stacking the collector drum onto a wooden case that raised it up high enough to connect directly to the cyclone, and it works like a charm! I guess I thought there would be no suction at the bottom of the cyclone - kinda silly in retrospect.....
So now I need to find a way to connect the drum to the cyclone from 5'4"" away.. I suspect that that long a piece of flex hose would collapse also, so perhaps some really strong rigid duct material? It comes in 5' lengths - anyone have experience cutting this stuff? While I'm at it, I guess I'll spend a few bucks and get some larger duct to at least start my run with.

Thanks for all the advice! You guys rock!
Dave

Dave,

Normally there isn't any suction there but.....

If a leak exists there, air gets pulled up into the cyclone diverting the dust up instead of letting gravity work. It's gravity that causes the larger particles to fall down into the barrel...unless there's a leak there....At least that is how I understand it to work.