Absolutely baffling!

[Bas]

Our frequent fliers probably remember the trash can separator Don built a couple of months ago. I copied his design and I've been very happy with the results.

Initially, I encountered a lot of "scrubbing", the phenomenon that the chips make it into the container but don't stay put. That's what you get for buying super-powerful HF equipment The scrubbing got worse as the trash can filled up, and I ended up having to empty the bag as often as the trash can itself. I was able to reduce the scrubbing somewhat by lengthening the pipe on the intake and shortening the pipe on the output. While not perfect, I now only had to empty the bag every other time.

I came across a new design for a separator lid, that uses a baffle underneath the pipes. I was somewhat skeptical since the inventor only used it with his shopvac, but I was also intrigued. A little particle board, a few dowels, and presto! Trashcan 2.0.

The results are spectacular to say the least. Scrubbing is now down to almost nothing, 95% of the material ends up in the trashcan! I included a couple of pictures to show how full the trashcan is and how empty the bag. Bear in mind that the trash can is 2' tall and has a 21' diameter. In the picture, it's about 2/3 full, with maybe two cups of dust in the bag (if that).

Pretty good for two hours of work and $8 in materials. Just remember: Use the 3/4" drill bit when using 3/4" dowel. Not the 7/8" bit.

[woodArtz]

I've been looking for a good separator for my Delta DC. Looks like you've got a winner here. I think I'll give it a go. Thanks for sharing!

[Dusty Sawyer]

Bas,

Looks like you've turned the basic can into a cyclone - more effective by keeping the chips in a swirl and away from the center output. I have the HF Chiwanese unit too, but went the extra 29 greenbacks for the premanufactured lid. I did take some of the flex tube going in and continue it on the inside of the lid in a downward arc to get the motion going at least, but it still lets too much get by. When I get to my new shop, I might try to put something like this together.

Extra Cool Tip!!!


Dusty

[dozer]

I like that design and will have to keep it in mind but first i need a dust collector.

[Bas]

Originally Posted by Dusty Sawyer

Looks like you've turned the basic can into a cyclone - more effective by keeping the chips in a swirl and away from the center output.

Well, to be clear - I didn't do anything. The guy that designed the baffle, Phil Thien, deserves all the credit. And Don for his initial design of course. It would have been difficult to modify a commercial separator lid, but Don's design looks like it was made for this.

Originally Posted by Dusty Sawyer

I have the HF Chiwanese unit too, but went the extra 29 greenbacks for the premanufactured lid.

Ooh, you big spender. Bet you're one of them 'fellers who buys that Domino thing

[scsmith42]

Bas, this is great info! I have a 2hp Grizzly collector, with their trash can preseparator, and it leaves a lot to be desired (both in terms of size as well as efficiency). I'm planning to upgrade the collector with the Wynn filters, and your link is quite timely in helping me to improve the cyclone as well.

Does anybody have any ideas about something other (ie larger) than the typical 30 gallon trash can to use as a cyclone?

Scott

[Joe Scharle]

Bas, how did you attach the dowels to the lid?
Joe

[Makinsawdust]

Scott,
I'm working on one using a 55gal steel drum with 6" metal pipe. I've got it made but I'm waiting on some misc. other fittings before I can get the system up and running. I'll let you know how it works. One thing that I have found to be true. When using the 30gal tc version, if you have a 90 degree elbow on the underside of the chip-into the can line you probably don't need a baffle. Without the elbow the can get's sucked dry. I've seen this with my 1.5hp and 3hp collector.
Rob

[scsmith42]

Robert, that's a great idea about using a 55 gallon drum - I've even got a few laying around!

My biggest challenge is volume. When I run the planer it generates a LOT of shavings; especially as I'm usually planing down RC lumber. In a few months when I get the Oliver set up I'll have an industrial sized system flowing into the dump truck, but I'll still need something smaller for my woodshop; hence my desire to upgrade the Grizz.

The only downfall that I see with the 55 gallon drum will be the weight when full. It may be a good idea to weld/bolt some handles onto the side of the drum to make dumping it easier.

What did you end up making your top from?

One other thing that I'm wondering...the inlet and outlet on the Grizz are 5" - 6", but their pre-separator has 4" inlet/outlets. I'm wondering if there is some benefit to using a smaller sized pipe for the entry/exit to the pre-separator (faster air velocity?) verus the lower flow restriction on a larger pipe?

Bas - did your research come up with any advice re the inlet/outlet size? Any other advice to share? I'd love to stop by your place and inspect yours for a better understanding - I'm having a hard time visualizing how the flow works inside the baffle that forces the chips to the bottom...

Scott

[Bas]

I marked the location of the dowels on the inside of the lid. The spacing doesn't have to be exact. I then drilled a pilot hole using a 5/64" bit through the center of each circle, all the way through the lid. From the outside of the lid, make a counter bore for the screws.

Next, I drilled a 3/8" hole in the inside of the lid (which is 5/8" particle board) with a Forstner bit (using the pilot hole to center the bit). I cut the dowels to 9", put them in the recess, and then from the outside of the lid drilled a pilot hole into the dowel, about 1 1/2" deep (using the pilot hole drilled previously as a guide).

I put some 5 minute epoxy in the recess, inserted the dowel, and screwed it to the lid using a #10 1 1/2" screw. Check for square before tightening the screw, it doesn't have to be perfect, but avoid tower of Pisa syndrome. The epoxy may be overkill, regular wood glue would probably suffice.

I used 5/8" particle board for the baffle, so the fastening procedure there is identical. Actually, I did the baffle side first (I suggest you do the same), but it's easier to explain this with the lid, since there is an inside/ outside

I read that the inventor of the baffle used 1/8" tempered hardboard. A simpler solution would be to use a piece of threaded rod screwed through the lid and hardboard, and fixed in place with washers and nuts.

Tip: If you plan to trim the output pipe, do it BEFORE you attach the baffle and the epoxy has set. Much easier that way.

[Bas]

The elbow is definitely critical. I was getting so much scrubbing initially I wondered if the separator was worth it. Angling the 90 degree elbow (and putting a small extension in it) helped quite a bit, but still wasn't great.

[Bas]

Originally Posted by scsmith42

Bas - did your research come up with any advice re the inlet/outlet size? Any other advice to share? I'd love to stop by your place and inspect yours for a better understanding - I'm having a hard time visualizing how the flow works inside the baffle that forces the chips to the bottom...Scott

Scott, you're more than welcome to come take a look, just send me a PM. The explanation is simple - it's magic! I'm beginning to see why the ClearVue cyclones are made from transparant plastic, I have no idea why the baffle works and how the air flows inside the trashcan.

From the author's notes, the idea is that the dust is spewed out of the 90 elbow and start to lose velocity as it circles the can (the baffle "ridge" ensures the dust circles and does not sink immediately or get blown all over the place). The dust then falls down through the drop slots along the edge.

I noticed after opening the can that there is a small hill directly under the baffle. The air must flow in such a way that chips swirl and pile up in the center, so that they stay put and not make it above the baffle.

As far as intake/ outlet size, I'd not reduce the size. You'll choke the whole system. In fact, for the separator, larger is better. You need velocity to move the larger chips, but you need volume to move the small dust particles. Obviously, there is a trade-off, or we'd all use 20" pipe. By the time you get to the separator, you don't want the larger chips to move on, so velocity becomes less important.

Hmmm, now you got me thinking. I'm using a reducer on my HF collector inlet, going from 5" to 4". Maybe I should modify the outlet on my trash can separator and make it 5". That should further help with the scrubbing.

Other advice - I put my DC in the far corner, to minimize the length of the runs. That's good engineering, but it's difficult to remove the can from there. If you make a lot of shavings, make sure it's close to the door. Casters on the can could also help.

[scsmith42]

Bas, I'll kick you a PM - probably next week to see about setting up a time to stop by. Thanks!

Scott

[junquecol]

Scott, now that winter has set in (70 degrees today), go across the street and "borrow" the water tank from the railroad. That would probably hold a days worth of shavings. Why not consider cutting the bottom out of the trash can and mounting it on top of a trailer/ dump truck? Maybe build the world's largest blast gate to fit between the bottom of trash can and chip collection box. Over in Cary, I have a friend who has his "WOOD" mag. cyclone upstairs in a his shop. His collection box is up against the ceiling down stairs and swings down on parrallel arms. One more post, and I will have a thousand posts! Of course a while back, post counter was running backwards, so I have probably already pasted this mile stone.

[scsmith42]

Hey Bruce - congrats on your 1K milestone, and thanks for the ideas! Unfortunatly, the RR's water tank is full... of water! I don't think that they'd appreciate it if I dumped 4K gallons on the ground in order to borrow the tank...

When I get my big blower set up (25hp), I plan on either dumping into a large manure spreader (275 bushel) or a dump truck. The dump truck will hold more shavings, but the spreader does a nicer job of distributing them. I've got a large fertilizer spreader that I could use also - but I'm not sure how well it would feed (tried spreading some ashes once but they tended to stick to the sides...) I'll have to mull these over a bit.

What would be nice to find would be a plastic 55 gallon drum with a removable lid. Light yet large, and I wouldn't have to fabricate a top. I can fall back on one of my 55 gallon steel drums if I have to, but that's a bit of weight added in terms of humping the shavings out of the shop. For the small shop, I borrow my wife's "2-horse manure spreader". It will hold about 4 trash cans of shavings before I have to empty it.

When I planed to recent mess of boards, I bypassed the bags and cans and simply blew the output from the dust collector right into the back of the dump truck. This is not practical for daily use though (had the planer set up outside the shop for a couple of days).

Scott