DC Reducer

[Marc Prudhomme]

Hi everyone,
I am using a reducer on my Delta 1 1/2 HP DC to connect the 4" port to th 2 1/2 port on my rigid table saw.
Am I doing anything wrong?Should this be done?
I sent an e-mail to Delta today to see what they have to say.It seems to be working ok but the only thing I have noticed is that the 1 micron filter bag is not blowing up like a baloon all the way.

Marc

[Jim O'Dell]

Marc, you'll really choke down the cfm if you do that. I have the Ridgid 3612 with the plastic housing under the saw that "had" the 2 1/2" coupler for the shop vac. I cut it out and attached a 6" piece of PVC with multiple layers of pure silicone adhesive. It works great. You could do the same with 4" PVC or a 4" metal HVAC adaptor. It will do much better for collecting the dust from the TS. See a picture of it here, post #68, first photo:
http://www.sawmillcreek.org/showthread.php?t=14427&page=3 I used a dremel with a spiral bit in it to cut out the hole...just go slow and keep your fingers clear! :eek: Jim.

[Marc Prudhomme]

Jim
I cant find post 68???

[Jim Becker]

Two things...the easy one first...a good quality filter bag will not inflate unless it's totally clogged.

The compromise you have using a 2 1/2" port on the saw is greatly reduced air flow. DC works by moving a lot of air at a given velocity and at low pressure. If you can increase the size of the saw's port to 4", your extraction will be significantly better.

[Bruce Wrenn]

A 3 X 4 PVC floor flange (commode) will fit into 4" flex, and also bolt up to your machine. Just inlarge the port area., and bolt her up.

[Jim O'Dell]

Jim
I cant find post 68???

Marc, I clicked on the link and then scrolled down about 6 or 7 posts and it was there. If you still can't find it, PM me and I'll send a copy of the picture. I originally tried to post the picture instead of the link, but it wouldn't let me since it has been posted before. Jim.

[Jim O'Dell]

Let's try this and see if it works. If so, for future use, right click picture, copy location, paste in new message. You may have to copy this link, and put it in the address bar...the first try didn't make it a clickable link in the preview. Jim (But now it is a clickable link...hmmmm:cool: )

http://www.sawmillcreek.org/attachment.php?attachmentid=48181&d=1160350845

And if a flange collar, like Bruce mentioned will work with your set up, it will be a lot easier to install in the shroud. cut the rough hole, place collar in from the inside, mark and drill holes, caulk, reinstall, and tighten bolts (I'd use carriage bolts from the inside).

[Marc Prudhomme]

Jim,
The filter bag was blowing up brand new out of the box.Its a 1 micron bag.Are you telling me that it should not be inflating at all????
Two things...the easy one first...a good quality filter bag will not inflate unless it's totally clogged.

The compromise you have using a 2 1/2" port on the saw is greatly reduced air flow. DC works by moving a lot of air at a given velocity and at low pressure. If you can increase the size of the saw's port to 4", your extraction will be significantly better.

[Jim Becker]

Jim,
The filter bag was blowing up brand new out of the box.Its a 1 micron bag.Are you telling me that it should not be inflating at all????

The "harder" it gets when the DC is running, the more restriction it's placing on the system. A high quality felt bag doesn't really "inflate" hard like a balloon because it's passing enough air to not build up as much pressure. Many of the filter bags from OEMs get rock hard, unfortunately.

[Marc Prudhomme]

So if I am getting less inflation with the 4-2 1/2 reducer connected to my Table saw, it is not a bad thing,its a good thing?
The "harder" it gets when the DC is running, the more restriction it's placing on the system. A high quality felt bag doesn't really "inflate" hard like a balloon because it's passing enough air to not build up as much pressure. Many of the filter bags from OEMs get rock hard, unfortunately.

[Jim Becker]

So if I am getting less inflation with the 4-2 1/2 reducer connected to my Table saw, it is not a bad thing,its a good thing?

Well...what it means is that you've restricted the inlet so much that there isn't enough air flow to "inflate" the bag! Pull the hose off when the machine is running to see the effect... ;)

Dust collectors depend upon moving a lot of air at a given speed and at low pressure. When you restrict the port, you restrict the amount of air available and you increase the pressure substantially. Performance is lower for those reasons.

[Jim O'Dell]

So if I am getting less inflation with the 4-2 1/2 reducer connected to my Table saw, it is not a bad thing,its a good thing?

I'm going to chime in here also. Marc, restricting to 2 1/2" would be a bad thing, IMHO.
There is a difference between a bag not balooning up because of the quality of the bag, and a bag, any bag, not balooning up because of restricted air flow. If your bag is saying limp because the inlet is restricted to a 2 1/2" opening, then the DC is not able to do it's optimum work of removing the dust and chips. But also, if you open it up to 6", it might not be good for that particular DC...might be too unrestricted and cause the motor to burn up. I'd say if the unit has a 4" hook up, stay with that size as much as possible. If you need to split off to run 2 ports on the same machine at the same time, (table saw with an added overhead pick up) then reducing them to keep the same area as a 4" pipe would be ok. Jim.