Dc-3300

hjlssfor1 · Post by **hjlssfor1** » Wed May 22, 2013 1:51 pm

I have a new jointer with a 4" dust port. If I were to connect a 4" hose from the jointer to the 2 1/2" hose of the DC-3300, what would likely happen? Thanks, Hank

frank81 · Post by **frank81** » Wed May 22, 2013 1:56 pm

hjlssfor1 wrote:I have a new jointer with a 4" dust port. If I were to connect a 4" hose from the jointer to the 2 1/2" hose of the DC-3300, what would likely happen? Thanks, Hank

It would be like throttling down the vacuum. You would have approximately 30-40% of the air flow speed on the end of a 4" hose as you would a 2 1/2" hose, all else held constant.

JPG · Post by **JPG** » Wed May 22, 2013 5:26 pm

frank81 wrote:It would be like throttling down the vacuum. You would have approximately 30-40% of the air flow speed on the end of a 4" hose as you would a 2 1/2" hose, all else held constant.

Connect the 4" to the three(3) 2 1/2" input ports on the dc 3300. Running a long 4" run is not recommended per Nick E. SS used to make a 4" port, but no longer IIUC. Yours may already have the larger port in front. Flapping off the top of me noggin here!

frank81 · Post by **frank81** » Wed May 22, 2013 6:48 pm

JPG40504 wrote:Connect the 4" to the three(3) 2 1/2" input ports on the dc 3300. Running a long 4" run is not recommended per Nick E. SS used to make a 4" port, but no longer IIUC. Yours may already have the larger port in front. Flapping off the top of me noggin here!

Also flapping off the top of my noggin, if you are shadetreeing the assembly described on the website, the smoother the pathway the more efficient it will be (lose less power). Think of what it looks like when 2 exhaust pipes come together, as compared to sticking 3 pipes into one side of a shoe box and one pipe in the opposite side. Three 2 1/2" hoses would theoretically handle more flow than the 4" hose (by 17%), so you could make a good but not great adapter and get the same power and ~80% the capacity of all three hoses combined.

Maybe that's not the question at all, its been a long day.

JPG · Post by **JPG** » Wed May 22, 2013 8:39 pm

'The question' was regarding connecting a 4" hose from a 4" jointer port to a 2 1/2" port on the DC 3300.

The 'problem' with a long 4" hose is the reduced velocity through it. In Nick's sawdust session, he advised against using pipe/hose larger than 3". In order to maintain effective movement of wood particles(a jointer will really really crank out a large volume rapidly),the velocity must be high enough to keep the particles suspended. He used a contrived fitting that connected three short 2 1/2" hoses to a 3" pvc pipe. This increased the flow volume, and therefore the velocity.

You are correct in advising against 'sharp' changes in direction. They reduce available static pressure which is an additional criteria. A 'Y' fitting rather than a 'T' fitting is preferred. A large radius 'elbow' is preferable to one with a smaller radius.

So back to 'the question' - use 4" hose as short as possible, and connect it to all three 2 1/2" DC3300 ports. Using the 4" adapter (no longer available) would make that easier. The cavity behind the ss logo on the inlet port is about 4" id. If yours has the removable plate, you could perhaps adapt to a 4" hose there.

hjlssfor1 · Post by **hjlssfor1** » Sun May 26, 2013 11:12 pm

Everyone, thanks for your replies. I have been AWOL because of a kitchen remodel and floor sanding. I will get back to my jointer/DC3300 issue eventually! Hank

hjlssfor1 · Post by **hjlssfor1** » Mon Aug 19, 2013 1:59 pm

I finally am getting back to spend some time in my shop, and I have been thinking about my 4" jointer port and the DC 3300. I am considering making from plywood a dust collection hood that would accept two 2 1/2" DC 3300 hoses (I have two hoses). The hood would face the 4" port coming out of the jointer.

I envision a rectangle, maybe 6" by 8", that would have two holes, one for each hose. My problem is the layout for the surrounding hood, which would be made of 4 pieces of plywood, and I cannot figure out the geometry to cut and attach the four hood pieces to the rectangular base (with the two holes).

If I were to bevel cut (45 degrees?) all four of the sides of the rectangular base, would that work? How do I determine the shape/dimensions (and edge angles) of the four pieces of the hood? Would I have excess plywood (from the four pieces of the hood) at the four corner joints with the rectangular base?

Is there an easy way to make these calculations?

Thanks, Hank

JPG · Post by **JPG** » Mon Aug 19, 2013 3:26 pm

Last I knew, a rectangular box had six sides.

First you decide upon the dimensions(length width height).

Then you decide upon joinery(miter/bevel/butt . . .).

Then you make the pieces to match those decisions.

Notice the second word in all three steps.

apexsunguitars · Post by **apexsunguitars** » Mon Aug 19, 2013 4:01 pm

So, as I understand it, you want to make a hood with both 2.5" pipe connections on one of the long sides of the box and face the open end at the 4" jointer port and hope that it sucks up the debris being jettisoned from the jointer port? Unless you get a tight seal around the port then you will be losing a good deal of suction and light particle will be going all over the place.

Maybe I am missing something here because, admittedly, I have not added dust collection to my SS yet. I do design mechanical instrumentation and piping systems so I know something about flow rates vs. linear velocity in a pipe. Not saying I am an expert but it seems to me that the thing to do would be to reduce the 4" to 2.5" right at the jointer. I have to believe that these fittings are universal among brands, they are just pipe. The Rockler catalog on my desk has a part 89195 reducer for 8 bucks. While the jointer may be creating a good deal of dust, its just small particlel size dust so you want high velocity, I would think running 2.5" all the way from the jointer to the collector would be the way to go and the increased velocity will create more suction around the jointer knives so that less dust escapes.

Just my somewhat educated guess.

JPG · Post by **JPG** » Mon Aug 19, 2013 4:17 pm

apexsunguitars wrote:So, as I understand it, you want to make a hood with both 2.5" pipe connections on one of the long sides of the box and face the open end at the 4" jointer port and hope that it sucks up the debris being jettisoned from the jointer port? Unless you get a tight seal around the port then you will be losing a good deal of suction and light particle will be going all over the place.

Maybe I am missing something here because, admittedly, I have not added dust collection to my SS yet. I do design mechanical instrumentation and piping systems so I know something about flow rates vs. linear velocity in a pipe. Not saying I am an expert but it seems to me that the thing to do would be to reduce the 4" to 2.5" right at the jointer. I have to believe that these fittings are universal among brands, they are just pipe. The Rockler catalog on my desk has a part 89195 reducer for 8 bucks. While the jointer may be creating a good deal of dust, its just small particlel size dust so you want high velocity, I would think running 2.5" all the way from the jointer to the collector would be the way to go and the increased velocity will create more suction around the jointer knives so that less dust escapes.

Just my somewhat educated guess.

Pretty good guess! Except a jointer creates large waste particles and considerable volume. You need the velocity to keep the heavier particles air born. You need the volume to handle the quantity. i.e. with a jointer/planer, you need both!;)

P.S. realize that any change in id also causes changes in velocity and possibly volume(due to restricting the area). Dropping the pipe size mid stream may cause clogging with high volume debris so the suggestion to go small early is a good one.