Blowing sawdust - TK blower

Bibbyman · April 24, 2004, 09:29:43 PM

It was a little over a month ago Mary and I made the trip to Kansas City to TimberKing to pick up our new dust blower. Well, we've not got the project completed but we're using it to suck the dust out of our Wood-Mizer LT40HDE25. We've still got to run a tube over to the edger to collect and expel that dust too.

I took the mounting bracket off and welded some plates to it so it could be mounted so it would blow out and not up.

Son Gabe was real handy when it came to standing on the ladder and setting it on the shelf we'd made out of full 2" oak. I think it weighed about 150 LBS.

The blower has a 5hp 220v motor and a 6" inlet and exhaust. The housing and blades are of cast aluminum. We used thin walled PVC pipe for the main plumbing – 6" going out and 4" to the mill and eventually to the edger. (Picked up some pieces today to get to work on that branch but opted to set in my Lazyboy instead of slugging around in the damp and rain.)

We first tried to use a section of 4" flex hose we got as a "bargain". But like most bargains, it didn't work and was not going to hold up. The suction was too great and it would suck flat. Plus, it was too light and after only a few hours of use stated to show holes.

Joint possition at hitch end of mill.

Joint possitioin at other end of mill - note it rotate 180 degrees.

This problem we solved that was in part inspired by the way Allen Root had rigged the hose to fit on his mill and a piece of connection we had left over from another dust collector – plus a little dumb luck. We could see one of the major problems was that the flex tube had to not only bend, it had to twist about 180 degrees as the sawhead traveled down the track. This twisting would soon unravel the flex hose. We came up with a fix that worked really well. We had a 5" to two 4" Y connector left over from another blower. The 5" port would slip over the 4" discharge chute of the mill and fit loose. I fixed the 4" hose to one of the outlets. The other outlet was not needed but already came with a cap. I had a bungi cord within reach to slip in the crotch of the joint and hook on each side of the mill chute. It had just the right strength to hold the joint tight on the chute and yet let it swivel. As the mill head traveled from one end to the other, the joint revolved and thus the flex pipe didn't have to twist. The simple hanging by the bungi cord is also handy when the need comes up to pull the tube off for cleaning large bark chunks out, etc. I may improve the system by making a little bracket or drilling some holes just for hooking the bunji cord on but for now, it works really well.

There is 40' of 6" PVC pipe blowing the dust out. It's over 12' off the ground at the exit end. We've done quite a bit of sawing and there is yet to be a build up of sawdust under the end of the pipe. It all tends to blow away and that don't break my heart one bit. We've had winds gusting to over 30mph and it has not done any damage to the pipe or frame holding it up. We did not glue the pipe joints as they tended to slip together plenty strong. They are held in place by some pipe hanger strip about every 10'. The two frames are built of left over 2x4s. There is a 2x6 (one 16' and the other 20') on top of the of the frames with a 1x6 flat on top of them to form a shelf for the pipe to rest on.

You can see some wires running across the aluminum housing and connecting to the blower frame. They are #8 copper wire that run the length of the plastic pipe on the inside – coming out through a hole in the pipe near the blower.

It's working all right now but I think it will work even better when we get the edger hooked up to it on another 4" line as I don't think we have enough air coming in for the size of pipe going out. We'll see.

oldsaw · April 24, 2004, 09:47:25 PM

I didn't get much done today either. My wife signed me up to make 20 bird feeders for her school. She didn't think it would be a lot of effort. My response was "What!!!!, are you NUTS!!!"

The little wooden tray portion was the easy part, then, each feeder has two support legs made of 1/8x1/2 steel flat stock. She thought I was exaggerating about how much piddly work was involved with the legs. I had to cut the stock to 12", pretty the ends up on the grinder, bend them to shape in matching pairs, center punch and drill 3 holes in each one, prep and paint, then dip one end in that tool rubberizer stuff. Then I have to attach them with two screws, and a third screw goes into a suction cup (I'm still waiting for) on each leg.

I would have like to put in some Laz-Boy time today. Would have been the perfect day for it. Tomorrow, I have more bird feeders to attend to. You have a far cooler project going than I do.

jdunmyer · April 25, 2004, 06:37:18 PM

I just ran a bunch of 4" PVC for dust collection in my wife's woodshop. Instead of using copper wire for static drain, I used electric fence wire. Had a 1/4 mile spool of it, and it should work just as well. Got it grounded all over the place, will post pics one of these days.

Don't know if it works or not, but I've noticed no static shocks or anything. Sorta like stomping my foot twice/hour to keep the wild tigers away: it must work, I've seen no tigers lately.

Percy · April 25, 2004, 07:04:11 PM

Heya Bibby.
Looks great. I never gave much thought to static but with plastic pipe I guess its an issue. I had a sawdust blower for my edger and while it did a good job of sawdust removal, all them little chunks of flitch that can come off the side of a close edged board played havock with the blower. Plugged always. If you can design some sort of grizzly to separate the sawdust from the chunks before it heads down the pipe, you will be laffin. Mine was such a pain that I built a custom wheelbarrow that fits under the edger and gets most of the sawdust till I can build a conveyor under the edger for sawdust/chunk removal. If yours works better than mine did on the edger, Ill be houndin you for details. ;D ;D

jdunmyer · April 25, 2004, 07:23:04 PM

Percy,
I'd think that all you'd have to do to keep "chunks" out of your blower is run the inlet pipe through a 'T' fitting somewhere along the line, with the inlet (from the sawdust source) going in one leg and the outlet (to the blower) out the side of the 'T'. The big pieces wouldn't make the right turn and should be able to be removed from the other leg of the 'T'. It'd be best if you could mount the 'T' vertically, inlet in the top, outlet out the side, and a blast gate on a "drip leg" coming out the bottom of the 'T'.

Bibbyman · April 25, 2004, 07:39:16 PM

We are planning to build a wooden box that will fit under the edger with the pipe coming in from one side. We may add some sloping sides to the box to help the sawdust find it's way to the suck'm-up hole. I have already built a metal frame and cut some flattened expanded metal to go over it. This I plan to install inside the edger below the blades at a steep angle. The idea being that the large chunks will slide off the grate and land on the floor to the side of the edger while the dust will fall through and get sucked up and out.

That's pretty much what ElectricAl did but I don't think he put in a grate. He says what ever gets sucked up the tube goes out the other end.

I'll take some pictures of these adaptations when I get them installed and working.

The Wood-Mizer comes with "fingers" in the dust chute as a safety measure to stop broken blades from exiting the housing. The fingers will often stop large chunks from getting into the pipe. The "Y" fitting (shown above) still has a couple of cross bars. They have yet to get clogged so I figure the fingers in the Wood-Mizer dust chute are working.

Frickman · April 25, 2004, 07:50:14 PM

Bibbyman,
How much air gets sucked in where the Y goes over the outlet? If it's a loose fit I assume it has a space there. Someday, in the long distant future, I plan to setup an LT70 next to the old Frick, and am boning up on all the details so I'll be ready when the time roles around.

On a side note, we run a 26" Cornell blower off the mandrel. If it can get it through the pipe, it'll suck it up and blow it out. Our two biggest problems are "shim" cuts taken when sizing a cant will cover up the intake pipe, and chunks that run through the blower will beat up the exhaust pipe, especially where it makes a 90 degree turn. We use green pvc sewer pipe, and the elbows where the vertical pipe attaches to the horizontal pipe have plenty of patches, clamps, and the "handyman's secret weapon, duct tape", sealing the holes shut.

Bibbyman · April 25, 2004, 08:06:11 PM

The 5" inlet pipe has a sloped shoulder about 5" down inside that the 4" chute on the Wood-Mizer kind of self centers on – kind of like a short section of funnel. It seals pretty tight and I see no leakage of sawdust out or can tell of any air being sucked in.

Now the chute on the Wood-Mizer is hinged and there is about a 2" x 4" gap between the hinged part and the main blade housing – on the bottom section. Some dust does fall out there and some air must be getting sucked in. I've thought about closing that off but it's such a small amount, I've not worried about it. I think for right now it needs all the air volume in it can get.

It won't get 100 percent anyway as there is always a lot of bark, bark from the debarker, dust of'n the boards when they are pulled and cant when they are turned. But it gets maybe 90 percent of the junk from clean fresh logs. (Old logs tend to loose a lot of bark and junk.)

AtLast · April 25, 2004, 08:42:45 PM

Real nice Bibbyman....I ran sch 30 in my shop to all my mess makers....at first I was all about running the wire to ground it..BUT after MUCH research I found out that the only real time you need to " ground" the pipe was if it was all metal....to each their own Im sure ..but Ive never had a problem with static electricity ..nor do I have any trouble should I touch it and worry about discharge....looks GREAT Bibby

shopteacher · April 26, 2004, 09:00:08 AM

Bibby, any idea of the blowers cfm?

Will_Johnson · April 26, 2004, 10:04:23 AM

Bibbyman asked that I field this question.

I work for TimberKing, which is owned by the same person who owns Woodmaster Tools, manufacturer (in the USA, by the way) of Bibbyman's blower.

The CFM is rated at 4900, but as you know this number is only so useful. Much depends on how far you're pulling the dust, how many outlets etc. In other words, static pressure.

I don't check FF as much as I should, so if you have more questions that I can help with, email me directly at willj@timberking.com. Or if you want the other members to benefit from my "wisdom" put up a post and email me to let me know it's there.

Best,

Will Johnson

Stump Jumper · July 17, 2004, 12:16:21 PM

:-[man did i miss this thread
bibby what kind of flex hose are you useing ??? i have been useing this thin vinel crap that only lasts 50hrs it gets full of pin holes >:(.

Bibbyman · July 18, 2004, 07:30:46 AM

Sorry about not getting back to you on that one. I had to have some thinking time.

The short answer is - Grizzly..

History. 8 or so years back we rigged up a dust blower and posted quite a bit about it. It was a 1hp unit from a cheap-o Grizzly $119 dust collection section. We got the 4" black flex tube from them. The flex tube lasted at least 5 years through 0 to 100 degree temperture days.

Then at last is started to come undone. We bought a new one from Grizzly and it only lasted about 6 months befor it started to break apart.

Then we saw an ad in one of the discount tool catalogs for 50' of flex hose for something like $12. It didn't last no time.

Then we got the TK blower. We rigged it up and used a new section of that thin dicsount hose. The TK blower would suck it flat. Soon it ripped apart.

We had a couple of sections of the first hose we got from Grizzly and the new hose we got from Grizzly and we put them together and came up with the swivel connection. I think this solved a big part of the problem. The hose hardly has any twisting stain on it now.

East_West_Dan · July 18, 2004, 01:23:42 PM

Oneida Air has a very tough clear flex hose that I use in the wood shop and have use on a mill. It's a bit stiffer than the thin stuff and cost more but it' real industrial grade. www.oneida-air.com .

Bibbyman · July 22, 2004, 04:20:38 PM

QuoteReal nice Bibbyman....I ran sch 30 in my shop to all my mess makers....at first I was all about running the wire to ground it..BUT after MUCH research I found out that the only real time you need to " ground" the pipe was if it was all metal....to each their own Im sure ..but Ive never had a problem with static electricity ..nor do I have any trouble should I touch it and worry about discharge....looks GREAT Bibby

AtLast,
Can you point us to where you got the info on the grounding/not grounding of plastic pipe? The one problem we're having is the stringy stuf is getting caught behind the ground wire and stuffing up the pipe.

Ga_Boy · July 22, 2004, 06:08:00 PM

Bibbyman,

I have done a good bit of research on the potential hazards of static with a dust collection sysytem. A good source is BIll Pentz's web site. Here is the web link:

http://billpentz.com//woodworking/cyclone/index.cfm

I also did a google search on static electricty hazard. If I recall correctly a engineer in Canada did an extensive study (on his own dime) regarding the reported hazards of static. His conclusions were for a wood shop the hazards do not exist. I do not have the link for this study but will look around and let you know what I find.

I am not sure what Atlast has maby he ran across the same or similar study.

Mark

Bibbyman · July 22, 2004, 07:27:21 PM

Thanks for the links and info. I got through some of it.

jgoodhart · July 22, 2004, 09:17:17 PM

I'm new here but, I have been reading the subjects at the forum for about a month now and I like it. Got a idea for keeping the chunks out of the vacuum blowers for ya. Take a 35 gallon drum or something that won't collapse run the duct into the drum around the middle and another pipe out the top ( bottom of drum) to the blower. I would put a NPT type fitting inside the drum to allow for adjustment in side so the big stuff fall into the drum and the saw dust goes bye bye. The reason for the npt fitting is so the inside piece can be removed to adjust the air gap between the in and out so all the dust don't stay in the drum. A couple snap latches to hold the lid on and you got a chunk remover blower saver.

chisel · July 23, 2004, 03:51:13 AM

QuoteI also did a google search on static electricty hazard. If I recall correctly a engineer in Canada did an extensive study (on his own dime) regarding the reported hazards of static. His conclusions were for a wood shop the hazards do not exist. I do not have the link for this study but will look around and let you know what I find.

Ga_Boy,
I think this is the article you're looking for:
http://mywebpages.comcast.net/rodec/woodworking/articles/DC_myths.html

Bibbyman,
I've read a fair amount on DC grounding, and from what I've read, it's useless to try to ground plastic pipe. Here's a quote from the link above under "Myths:"

"2. The number two myth must be that you can ground PVC. You simply can't ground an insulator. There are things you can do to reduce the odds of a strong discharge, especially to your body, but they are far from perfect."

Ga_Boy · July 23, 2004, 03:18:20 PM

Chisel,

That is it. I found it again this afternoon and printed it out, its 15 pages long but a very good article. Worth the read.

Jgoodhart,

Good idea on the seperator, however (there is always a however), the air flow from the blower will most likely be such that the chuncks will remain suspended in the air stream; thus not settelling in the can. Once you move into the 14" and larger blowers these seperators are not efficent, you need a cyclone.

Check out the web link above for Bill's page. It took me the better part of six weeks to read it all.

Mark

johnjbc · July 25, 2004, 06:36:10 PM

Welcome to the Forum, its good to see someone else from Carlisle on. here
This is a great place for information on sawing and milling
Looking forward to meeting you sometime.

ElectricAl · July 26, 2004, 08:17:30 PM

We used a 5" drain tile Y on the saw. The lower part is open to keep the CFM rating up. Also the flex tube is 5".
We found that 4" is way too small for how fast we saw.

The 5" flex tube hangs on a 24" to 36" spring. It keeps the tube out of the way, but streches for the long cuts.

5" Flex tube connects to a 6" main line and 6" T . At the T dust goes through the wall to the blower and 110' of 6" pipe to a wagon.
Left of the T is a Y connector. The 6" riser pipe goes up and across the ceiling and down to a 20" planer. Left of that is a 4" line that runs along the floor to the edger.

The edger pit has one sloped side and the 4" pickup is at the bottom. Large chunks just fall in front of the tube so we check and clean hourly. Any strings either wad up at the blast gate or go through the impeller.

This is a minimum maintenance system and is 3 years old in this configuration.

Bibbyman · July 28, 2004, 07:55:37 PM

Thanks E-Al for documenting your dust blower system. E-Al and I have been exchanging ideas for several years now. I hope he's picked up an idea or two from me and Mary. But I think I've probably been inspired more by the things he and Linda have worked out and shared with us.

E-Al was right in there when I had a thousand questions about going 3ph.

Did you note the similar way we used a Y connection on the tube to chute? We just happened to use the bungi cord and it solves the twist problem. E-Al has his Y connection fixed to the chute but it works because his tube lies on the floor and snakes back and forth.