Do it right the first time...

[numbskull]

This stuff confuses me no end.

As I understand it, larger ducts are more efficient, but require higher HP blowers to maintain air velocity high enough to carry chips, which is why most home shop collectors are designed for smaller duct work. For 6" pipe you may be looking at 3-5hp machines. You also need to upgrade the dust bags (both quality and surface area)to handle this increased pressure (or the dangerous small dust gets blown right through). Finally, most good systems now make use of a cyclone to reduce bag clogging. The cyclone has to be designed specifically for the HP of the collector. Even then, capturing the dust/chips at the source becomes a nightmare.

[Rockfish9]

Originally Posted by numbskull

This stuff confuses me no end.

As I understand it, larger ducts are more efficient, but require higher HP blowers to maintain air velocity high enough to carry chips, which is why most home shop collectors are designed for smaller duct work. For 6" pipe you may be looking at 3-5hp machines. You also need to upgrade the dust bags (both quality and surface area)to handle this increased pressure (or the dangerous small dust gets blown right through). Finally, most good systems now make use of a cyclone to reduce bag clogging. The cyclone has to be designed specifically for the HP of the collector. Even then, capturing the dust/chips at the source becomes a nightmare.

the main purpose of a cyclone is to cut down on the debris passing through your impeller , thus landing in a collection bin instead of a bag that needs to be cleand/emptied
I actualy have charts and formulas for figuring this stuff out.. I'm already running 1 micron 40 gallon bags( which even when cleaned, have a shelf life) and a cyclone pre sepperator...my blower wheel is 11.5".. and free wheels at 3450 rpm's.. and even though the port is 4" it moves a sufficient volumne of air..... the smaller the pipe, the more resistance, the more turns/"t"s the more resistance.. branch speed should be approx 400 fpm.. main trunk approx 350fpm.... all that said, I wanted to upgrade to a canister type fine dust filter instead of a pair of bags( a royal PITA service).... in the end, the cost of a new canister, was half of a new unit.. I just ordered a 2 HP, 1500 cfm unit.... with 1 mic canister filter and disposable 60 gallon bags.... DONE!

[Grapenuts]

all these problems wood disappear if u just shot it right outside..no back presure from bags or cans to interfear....it's called mulch and I don't care what part of the country your from,it's what makes loam.

[eskimo]

Finally grounded my DC this past weekend after having the kit for 6 months. Never felt like I turned enough to cause a problem but I'm usually the example whenever I think like that.

I also changed from T's to Y's after seeing a friends setup that he uses for making cutting boards. Also wish I paid up and got metal blast gates when I purchased the plastic kind.

[Diggin Jiggin]

I run a shop vac, but only once or twice a year.
Ahhh shop envy...

[GFGF]

Bought my grizzly cyclone dec 08 but couldnt afford the ductwork untill dec 09. gave me plenty of time to concider duct design. " Bills cyclone" web page has lots of info.
my take on it: keep the ducts as large as possible for as long as u can. if and when you do get down to 4" plastic, try using stickey foil tape inside and out of the pipe with a screw or bolt to connect the 2 for a ground.
if u stay with a 7 or 6" duct, there's a huge diff. in volume when u bush that pipe down to 2.25" ( shop vac hose) your shop vac will have more suction than the dust system.big impeller=big duct
I started my woodshop in 1988 but never felt i needed a DCS untill i started turning lures a few years ago. wrong.shulda done it sooner .cough cough.
GF

[Pete F.]

Originally Posted by Grapenuts

all these problems wood disappear if u just shot it right outside..no back presure from bags or cans to interfear....it's called mulch and I don't care what part of the country your from,it's what makes loam.

And I thought that was my secret

[Rockfish9]

Now that I've been using it for a few weeks, and have recieved several PM's and questions about the new system, I'll share what I've done...in pictures.

the new DC is a PSI 1500 cfm single stage powered by a 2 HP motor turning a 12" steel impeller.. the inlet is 6" and coinsides nicely with my 6" Main trunk duct work... I originaly wanted to install a cyclone, but I have height limitations and a cyclone with enough cfm simply wont fit... this one make it by 1/2"... I chose a 1 micron canister type that is 40" tall and gives superrior filteration to a bag type, a disposable bag catches the debis that is drawn in or shaken from the canister...I've included the fan curve with my first photo...

[Rockfish9]

pictured are the main ducts and the branches, because I had over 40' of plastic, i did utilize it for the branch ducts that could accomodate 4" restrictions...notice the spiral wrap of bare copper on the pipe, ther is also a ground wire on the inside, they are mated externaly and grounded to the main pipe which is in turn grounded to the collector , each branch is also terminated at each machine..

[Rockfish9]

the first branch terminates at the lathe and a floor sweep directly under the lathe, aluminum blast gates control the flow to either duct...

[Rockfish9]

the first shot is kind of a long view of the duct work as it travels away from the DC...

Next picture is of a small hood I affixed to the chop saw, this was problematic and took several tries to get it right.. now it is nearly perfect..

on the same table, controlled by it's own drop and blast gate is the drill press...