Another dumb DC thought...

[dbhost]

A not so hypothetical question here...

I have a BT3100 fitted with a belly pan, and a shark guard. I have 3 points of DC pickup for this saw. I have temporarily fitted the saw with a 2.5" hose Y to connect the belly pan, and the main DC pickup from the motor. The dust collection from this is tolerable as long as I go hose straight to the cyclone instead of through the plumbing (just too many CFM drops on the way there). Obviously the shop vac is NOT going to be able to get all 3 ports. The question is this...

As I have mentioned, a Delta 50-760 is on the as soon as money appears list... I know the 50-760 has a 2 @ 4" to ???" Y input.

Can anyone tell me what size that input is? I am hoping it is 6", but not holding my breath for it...

IF for some odd reason this is actually 6", I would assume I could do the following...

Plumb the entire system 6" to wye fittings. I figure I could try a dual branch 6"x6" straight x 4" x 4" to the branches. Run a single 4" to the belly pan, and then a 4x2.5x2.5" wye to pick up from the motor and shark guard. But how to route the hose for the shark guard?

Ah if dust collection / control were easy, or inexpensive, we would all be done with it by now I bet...

[Tom Miller]

I think that'd be pushing it to try running a 6" system with a 1.5hp DC. You need to have a bare minimum of ~3500 ft/min to keep dust moving, and through a 6" pipe this comes out to 700 CFM (not to be confused with over-inflated CFM ratings of DCs, BTW).

Regards,
Tom

[poolhound]

I have a 50-760 and the Y input is bigger than 4" but less tha 6", i just tried to measure it and its approx 5 and change (rough eyeball with a tape).

I have the same setup you are looking at. I tried to get all three ports running from the same hose but it didnt seem to work well. I have my belly pan and shroud port connected with 4" hose (reducer fitted for the shroud port) to a Y that I attach the DC to. I then run a hose from my shop vac separatley to the SG port suspended from the ceiling on a bungee.

I am sure there are other ways to configure the DC plumbing but this seemed to be the best option for me. If you figure out a better way do let me know.

[dbhost]

I have a 50-760 and the Y input is bigger than 4" but less tha 6", i just tried to measure it and its approx 5 and change (rough eyeball with a tape).

I have the same setup you are looking at. I tried to get all three ports running from the same hose but it didnt seem to work well. I have my belly pan and shroud port connected with 4" hose (reducer fitted for the shroud port) to a Y that I attach the DC to. I then run a hose from my shop vac separatley to the SG port suspended from the ceiling on a bungee.

I am sure there are other ways to configure the DC plumbing but this seemed to be the best option for me. If you figure out a better way do let me know.

Can you post up pics of your arrangement on the saw? I get the shark guard / shop vac setup, and I am keeping the vac setup, I don't mind running 2 at once. Just want to make sure I am getting the dust...

Are you using a 4" wye, and reducing to a 2.5" hose to go to the back of the motor? From what I can tell so far anyway, I reduced the original owners 4" on the belly pan to 2.5" and I get everything out of the belly with the shop vac no problem...

Just thinking out loud here guys... Ignore me if I am sounding too stupid here...

So if I go...
2.5" from belly pan (I know it works) to 2.5x4" adapter, preferrably a conical one into a 4" wye AND...

2.5" from the back of the motor to a 2.5x4" adapter to the other leg of that same wye, and then that into the 4" trunk back to the cyclone, and finally to the 50-760...

Shark Guard with 2.5" hose, bungee'd to the ceiling, and over to the shop vac system...

Am I on the right track here?

I know the shop vac handles the split fine, but that has a pretty high static lift, with mediocre CFM, a DC will provide good CFM, with mediocre static lift...

Somebody needs to design a best of both worlds machine, TONS of CFM AND static lift...

[LarryG]

Just thinking out loud here guys... Ignore me if I am sounding too stupid here...

What's that noise? Did somebody say something?

My 2HP HF DC has a two-4"-into-one-5" inlet. IINM, this is fairly standard for this general class of machines.

[poolhound]

Can you post up pics of your arrangement on the saw? I get the shark guard / shop vac setup, and I am keeping the vac setup, I don't mind running 2 at once. Just want to make sure I am getting the dust...

Are you using a 4" wye, and reducing to a 2.5" hose to go to the back of the motor? From what I can tell so far anyway, I reduced the original owners 4" on the belly pan to 2.5" and I get everything out of the belly with the shop vac no problem...

Just thinking out loud here guys... Ignore me if I am sounding too stupid here...

So if I go...
2.5" from belly pan (I know it works) to 2.5x4" adapter, preferrably a conical one into a 4" wye AND...

2.5" from the back of the motor to a 2.5x4" adapter to the other leg of that same wye, and then that into the 4" trunk back to the cyclone, and finally to the 50-760...

Shark Guard with 2.5" hose, bungee'd to the ceiling, and over to the shop vac system...

Am I on the right track here?

I know the shop vac handles the split fine, but that has a pretty high static lift, with mediocre CFM, a DC will provide good CFM, with mediocre static lift...

Somebody needs to design a best of both worlds machine, TONS of CFM AND static lift...

I will try and take some pics later. As I recall I think I used various plumbing connectors and th input to the belly is 3" I will have to check.

If you really want to get rid of 99.9% of the dust and suck like a black hole just drop a few grand on Oneida

[LCHIEN]

in a DC system you have conflicting requirements.
One you want to keep the piping large diameter to reduce the restriction which allows maximal CFMs (cubic feet per minute) to catch all the fine dust particles and keep them from floating away. once you reach a certain restriction, the DC motor can't pump enough pressure to keep the CFMs up.
Two you want to keep the piping diameter small enough to maintain resonable velocity (in linear feet per minute) so that the particles (especially the more coarse ones) won't fall out of the airstream and ultimately plug your piping.
As Tom miller said, with 6" you will not be able to keep 3000+ linear FPM with that 1.5 HP DC.
Longer pipe, larger diameter, you have to make up for it with more HP and more CFMs.

The HF 2HP DC has a 5" inlet wy'ed to 2- 4".
Actually, its fairly easy to take the round plate off the inlet face of the impellor housing, cut a new round plate of plywood (with matching screw holes and mount the port size of your hearts content in the center.

[poolhound]

OK, just for you I have continued my day job avoidance scheme and just gone out there and taken some pics, I guess I will have to invoice you now .

You can see that the Y is 4" and I use one of the quick connect adaptors (see pic, rockler I recall) on the end of my DC hose. It fits snugly inside this Y. Under the saw on the belly pan the 4" hose fits around a 3" waste pipe. I used a 3x3x2 as orginally I had intended to take the 2" back up to my SG. As I mentioned earlier this didnt really work well so I just plugged the 2" hole.

[Uncle Cracker]

The inlet on the 50-750 is 5".

[master53yoda]

pipe sizing

a 4" pipe will feed 2ea 2.5 " pipes with a little to spare.
a 5" pipe will feed 4ea 2.5 " pipes

this IS pipe not flex a 4 " pipe would feed 3ea 2.5" flexes that are 4' long.

The flex causes major turbulence and restricts the static pressure form the dust collector.

The piping loses are not compensated by increasing the HP on the DC as the static pressure remains the same from one size DC to the next. What changes is the CFM but that can not be delivered without larger pipe. If you go to large on the pipe for the CFM the velocity will not be high enough to lift the dust on a rise or it will separate on a horizontal run.

I use 3" RV sewer hose instead of 2.5" vacuum hoses when I run to 2.5" ports with far better dust collection. Also the 3" RV hose is cheaper then vacuum cleaner hose is. The 3" hose delivers the static pressure and cfm to the tool rather then reducing the static pressure in the hose. the loss of static pressure reduces the cfm at the machine.

A good example of this is the collector hose off of my Rigid planer. The port is 2.5" put the collection is far better when I run the 3" RV hose instead of the of the 2.5" vacuum cleaner hose.

Dust collection piping systems can have problems if the piping is to large or to small to match the DC. Small particulate movement.