Cyclone lid for my DC. Good/Bad???

[Brian Hale]

Are the ones that fit a 30 gallon trash can a good idea? Will they reduce the power of my 1100cfm DC? Can i put a trash bag in it or will it get sucked up?:eek:

I'm wanting to put it between the planer and DC...

Brian :D

[Tony Falotico]

Yes, They are great at capturing most of the chips.
Yes, it will reduce the airflow.
Don't know about the trash bag, haven't tried one.

I personally think the idea is great but am not pleased with the airflow reduction. By watching the circular air motion in the DC collection bag, there is a noticeable difference when the cyclone lid is connected vrs. not connected. I'm toying with the idea a building one using 6" vrs the standard 4" hose. Someone posted a pic of one they made out of a plastic trash can a few months back.

If you are just going to use it for your planer, I'd say go for it. Saves bags on the DC unit.

[Howard Acheson]

Yes, you can use a trash bag. But, you must use some method to keep it from collapsing. Get a piece of formica. It should be as wide as the depth of your collection can and as long as the inside circumfrence of the can. Put the bag in then roll the formica to something smaller in diameter than your collection can, put in the can an let it gently unroll. It will hold the bag open.

Any type of sheet plastic can be substituted for the formica.

[Brian Hale]

Cool! Looks like an order from Grizzly is in the near future. Hmmm What else do i need :cool:

Howard, that is one of the best tips i've heard in a long long time!! I was considering something like a couple of bricks but i'd need to dig them out each time. I assume the plastic/formica just slips right out when the bag is full. Cool!

Thanks guys!
Brian :)

[Mike Stanton]

I have one from woodcraft they sell two kinds get the one that has and elbow on the inside it is better than the other one.It has a coupling on the top also. Mike

[Gene Hatcher]

Brian, take a look at Lee Valley's version. I bought one recently and it works great! Hoses are inline, ie. in a straight line from machine to DC. Fits the 30 gal metal cans and seals well under pressure.

[Gary Whitt]

This site might shed some light on your situation.
There is a lot of research here.

http://cnets.net/~eclectic/woodworking/cyclone/DC4Dummies.cfm#VendorClaims

[Mike Kelly]

I use a trash bag in my Oneida, with a plastic liner that is used to hold a bag up when raking up leaves and grass in your yard. Just roll it up and unfurl it in your barrel inside the trash bag. It keeps the bottom of the bag on the bottom, and the sides against the sides (gets the trapped air out). When full, lift out the liner, tie the bag, lift the bag out and dispose of without all the dust of dumping. Without something like this a bag doesn't work very well. The cyclone gets air under the bag and it only gets about 1/4 full before it clogs up the down tube.

[Bill Pentz]

The two different types of so called "cyclone lids" commercially available are actually separator lids. Both provide good chip collection with the one having the internal tube being more efficient. If you have a 1 hp or smaller DC, they work pretty well, but will kill performance and not work so well with a 1.5 hp or larger DC and use the recommended 6" or larger ducting needed to move the volumes of air for our larger tools.

There are a number of problems with these units. Both use 4" ducting which is too small to move the volumes of air we need for our larger tools. Both generate around 4-5" resistance, almost one horse power, and that is two to four times the resistance you will get from a well designed cyclone. That resistance kills airflow.

bill

[Brian Hale]

Lots of good information here; Thanks!

My DC is the Bridgewood BW002A, 2hp, 12" impeller and 1100cfm at 5" static pressure. If i understand things right, i should not use one of these trashcan seperators because my DC is too powerful?
The DC has (1) 5" port and a "Y" with (2) 4" ports that slides over the 5". Will it increase the resistance to the point that i won't be moving chips or will it just not be effective for dust?

More confused than before..
Brian :confused:

[Bill Pentz]

If you are using the two 4" lines from your wye then you can use one of these as the 4" ducting will cut the airflow to a level that will work with one of these trashcan separators.

These units work by combining two different separation processes.
1. To a small degree they act as centrifugal separators, another name for a cyclonic separator. They separate dust and chunks off by forcing the air to turn a sharper corner than the debris can turn launching the debris out of the airstream. They also work with a little centrifugal action where a spinning airstream pushes the particles against the wall of the trash can where the airflow is slower allowing the particles to drop.
2. Moreso they act as drop boxes. A drop box is an opening in a pipe that is large enough that the airflow velocity falls below what is required to keep the larger particles separated. If you divide CFM by the square feet area you get FPM. When the FPM drops below about 3200 sawdust and chips drop out. When it drops below 50 FPM so does fine dust.

Although staying with the 4" hose will work with a separator lid, to get a unit that will work with your wye connector removed and 6" hoses you need a 5'2" diameter garbage can that stands about 7' tall. Otherwise, you will find just as so many others and I did that the increased airflow of the bigger ducting with a unit as big as yours keeps all but the large blocks from staying in the garbage can. That airflow simply keeps it scoured clean.

Finally, the more turbulence you have in your trashcan the more energy that is used and the poorer the fine dust collection. Most of these trashcan separator lids require two to four times as much power to run for far less separation than with a cyclone.

bill

[Brian Hale]

Great info there Bill! I thought i had a reasonable understanding of what i needed/wanted/could afford in my DC system and while this Bridgewood is a fine, well built piece that fit my budget and current space, a true cyclone is still on the list when the new shop gets built. I've also added a home built air filter with a 12"wide x 11" diameter squirrel cage blower from an old oil fired furnance. Between the 2 the surfaces in my shop stay quite clean even under heavy/sanding sawing.

I'll order the lid from Lee Valley tomorrow.

Thanks again for your input and most importantly for maintaining your DC website. Most, if not all of my DC knowledge came from your site and i'm sure the same is true of others.

Best wishes
Brian :)