Shopsmith Forums

rocke1 wrote:The 4 inch to 2 1/2 inch adapter means more loss and the velocity in the short 4 inch flex hose really drops the advetised 6750 fpm for the Jet way down so that the hose holds a bit of dust in the folds of the hose.

Rock,

some of the discussions here have talked about partially opening a second port on the DC3300. I find that helps me if I use a gate valve and open it until I hear the difference. if the 2.5" hose on your system is throttling the air too much, then you might try bleeding in some extra air into the 4" manifold so that it mixes with the air coming in from the 2.5" hose.

Ivan

Another nice feature of the SS DC3300 is the noise level. Because the motor inside the unit the noise level is reduced.

I had a Grizzly and sold it and purchased the DC3300. I was not impressed with how it performed and it was noisy.

Ivan:

I first saw the 3500 fpm number in Nick Englers "designing a dust collection system" sawdust session. I forget which # session it is but it is still active on Shopsmith's web site. I have since seen that number published in at least one other source as well.

I believe that the 3500 fpm figure was determined through actual testing. The air velocity in the pipe, generated from a given power source, is of course dependent on pipe diameter. It takes less HP to achieve that velocity in a 2 1/2" hose than in 4" or 6". Thus my comment that many woodworkers are oversizing their dust collection systems because the woodworking magazines have convinced everyone that they have to have at least 4" ductwork.

Reaching far back into my memory bank, to the old days in fluid machanics class, the Reynolds number indicates the point of transition from laminar flow to turbulent along the boundry layer. Right on the inside surface of the pipe, the air velocity is zero, and the velocity increases in a parabolic manner as you measure the velocity up to the center. So, somewhere perhaps only a few thousands of an inch above the interior surface of the pipe, there is laminar flow at a much lower velocity. Correct me if I'm not remembering this correctly.

Yet another view point on the subject.

Now if you are going to look at this please read all of it... and it will take sometime so maybe instead of watching the super bowl??? Seriously read it all.

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

Ed

Woodcraft has a steel city dust collector close out priced at $190.00. I bit on it. Now comes the ducting and switching. I want to put the collector in an adjoining room so I need to switch it near the tools. Convenience would put switches at each tool. Suggestions & logistics?

Secondly, ductwork. I am thinking 4" pvc. A friend had a custom violin case shop. It burned. He blamed it on static electricity in the pvc ductwork connected to his collector. He rebuilt the shop with the same pvc ductwork but screwed a sheetmetal screw into the pipe every 3' and connected these with wire that was connected to a ground. Has had no more problems.

Please direct me. Don't like fires. Don't like to unplug duct lines. Don't like spending money.

For remote switching, how about one of those remote controlled power strips used for outdoor Christmas lights? I used one of those at my old house for a contraption I built to improve the clothes dryer venting and it worked great. Plug the DC into it and keep the remote in your pocket.

heathicus wrote:For remote switching, how about one of those remote controlled power strips used for outdoor Christmas lights? I used one of those at my old house for a contraption I built to improve the clothes dryer venting and it worked great. Plug the DC into it and keep the remote in your pocket.

What kind of a amp rating do they have? The dustcollector is 1 1/2 hp. Not an electrician...don't know the amp rating.

burkhome wrote:What kind of a amp rating do they have? The dustcollector is 1 1/2 hp. Not an electrician...don't know the amp rating.

"Damnit, Jim, I'm a doctor, not an electrician!" Except I'm not a doctor either. But to answer your question, I don't know. There are many different versions available and you'd just have to check before you buy. Looks like the one beeg linked to above should do the trick.

Or you could build your own!

http://www.instructables.com/id/Remote- ... wer-Strip/

heathicus wrote:"Damnit, Jim, I'm a doctor, not an electrician!" .......

http://www.youtube.com/watch?v=bVhcB9ucmdg