Thread: yet another newbie 2hp question

Karl, you can't use the Impeller and motor from a 2HP DC on a BP designed cyclone and expect it to perform anywhere near like a BP cyclone.
If you do that and do not use any filters the cyclone may release a lot more fine dust.

The other issue with adding anything like a cyclone or chip collector to a 2HP DC is that it compromises the flow from the very beginning.
A home made cyclone will eat up valuable pressure and rob flow from an already compromised system so a system that starts out with 800 cfm will be down to 600 cfm simply by placing a cyclone on it..

The main perceived advantage of using a cyclone is that you do not have to empty bags as often (some people at their risk never clean them at all). It's obvious, when bags fill up the flow will slow down very quickly. What 99% of cyclone users do is look at the cupful of dust in the bottom of the bag and and say " well the bags are not full so the filters don't need cleaning", but they never stop to measure the flow and it is simply not possible to tell what is going on by placing a hand over inlet. To maintain max flow using a cyclone the filters/bags should be cleaned every time the chip bin is emptied otherwise the filters will still clog up and compromise flow. So there is no advantage on a small powered system. Cyclones work on systems that can generate a lot of pressure or flow.

The only way to maintain max flow on a small system is to eliminate as much as possible from the air pathways and that includes keeping the bags/filters as clean as possible

There is a good reason that the BP uses a 4HP motor and a 15/16" impeller and that is to get the initial pressures, flow rates, and air speeds required inside and outside the cyclone. Using anything less will not work anywhere near as well.

Originally Posted by BobL

Karl, you can't use the Impeller and motor from a 2HP DC on a BP designed cyclone and expect it to perform anywhere near like a BP cyclone.
If you do that and do not use any filters the cyclone may release a lot more fine dust.

The other issue with adding anything like a cyclone or chip collector to a 2HP DC is that it compromises the flow from the very beginning.
A home made cyclone will eat up valuable pressure and rob flow from an already compromised system so a system that starts out with 800 cfm will be down to 600 cfm simply by placing a cyclone on it..

The main perceived advantage of using a cyclone is that you do not have to empty bags as often (some people at their risk never clean them at all). It's obvious, when bags fill up the flow will slow down very quickly. What 99% of cyclone users do is look at the cupful of dust in the bottom of the bag and and say " well the bags are not full so the filters don't need cleaning", but they never stop to measure the flow and it is simply not possible to tell what is going on by placing a hand over inlet. To maintain max flow using a cyclone the filters/bags should be cleaned every time the chip bin is emptied otherwise the filters will still clog up and compromise flow. So there is no advantage on a small powered system. Cyclones work on systems that can generate a lot of pressure or flow.

The only way to maintain max flow on a small system is to eliminate as much as possible from the air pathways and that includes keeping the bags/filters as clean as possible

There is a good reason that the BP uses a 4HP motor and a 15/16" impeller and that is to get the initial pressures, flow rates, and air speeds required inside and outside the cyclone. Using anything less will not work anywhere near as well.

Thanks Bob, very much appreciate the indepth response. I will go ahead and build an "airtight" cabinet vented outside above roof line using just the needlefelt filters until I can convince SWMBO to increase my hobby budget.

Cheers
Karl

fyi i bought a second hand 2hp carbatec duty last week

i read the forum and took the advice and removed the dual 4 inch connection and instead installed a 6 inch x 1 metre plastic pipe to the extractor

it did made a big difference (feels like its going to suck my hand in!)

Originally Posted by cowenan

fyi i bought a second hand 2hp carbatec duty last week
i read the forum and took the advice and removed the dual 4 inch connection and instead installed a 6 inch x 1 metre plastic pipe to the extractor
it did made a big difference (feels like its going to suck my hand in!)

There are two more bottlenecks on the generic 2HP DCs that if you address will enable you to get even more out of that DC.
The stock DC inlet is only 4.5" so it is really worth replacing that with a 6" DC inlet.
The other is the 5" flexy between the impeller and the bag housing.

hi bob

the inlet on the one i have is 6 inch. or touch under. as i was able to force a 150mm pvc pipe over it

i also have a canister on the top

not sure how i can modify the flexy between the fan and catcher. i have read your other posts about this but not sure i can modify it easily

i have it hooked straight intro a jet xacta trable saw and itr works greatr. the saw has the shroud around trhe blade to help dust collection

im waiting for a shark guard and will then connect a dust extractor to that to help with collection on top of the table.