J. Phil Thien's Projects

Nice! good job

In the back of your pic it looks like you moved your motor up on your new DC.  Could you twist it and than put your baffle under it for a direct connection to get rid of the flex pipe that is twisted. Could see a good increase in CFMs.

the cutout 240 degree ends where the dust comes in or the non cut out part starts just below where the dust comes in.

I not sure now what you are making. There are two thien things you could try.

1. An internal baffle which is just one piece of wood (240 cut out ) in your machine...This will improve dust getting to your filter. How much I am not sure but wild guess; half. The good thing is that very little change in air flow.

2. Build a top hat: Which I think you are talking about because you asked how far a pipe should protrude.  I would stay with the 8" from the blower to the tophat but switch to 6" for dust duct. 8" pipe should protrude about 2/3 of the way into the tophat. You might read here about retired2 build. Mind you will see your 2400 cfms drop to 1450 plus or minus  but your filter will see little dust at all.

I am far from an expert also, but at 2400 cfm you need to reduce it to 6" you do not have the impeller or hp to support a 10" or 8" in a two stage DC. I think if you want to go with a two stage you be best to buy the clear vue cyclone 6" model. You might call clear vue and ask.

I put a thien baffle in a 2 hp grizzly like what you are talking about but did not reduce the air to the filter. It did help with filter clog and did not seem to reduce air flow. I then made a thien tophat that went before the blower. It caught more dust but had a 40 % reduction in air flow. I than upgraded to a clear vue 5hp with a 16" impeller. I still was not happy with the reduction in air flow. So I went to the full clear vue cyclone. Result is that the clear vue cyclone is much better at reducing less air flow and I think base on my visual that it catches more dust.
You didn't state what size impeller you have but based clear vue 15" for 6" pipe and 16" for 8" pipe. You can reduce your 10 " to 6" or 8".
Most motors spin at 3450 rpms regardless of hp so impeller size is needed.

from bill pentz site

HVAC Blowers
Many write asking if they can use Heating Ventilation and Air Conditioning (HVAC) blowers for dust collection because these blowers are so common and inexpensive. HVAC blowers typically use a squirrel cage type blower. Squirrel cage blowers have a round slotted cylinder that sucks the air in from the sides into the center then pushes it out a blower outlet. Because HVAC Blowers can move plenty of air in terms of volume they make good air cleaners. They make terrible dust collector blowers because they cannot generate the pressures needed to overcome the resistance of our hoods, ports, ducting, separators, and filters.

It seems to me that the bell mouth is encouraging the air in a bigger diameter that may be dusty. I know that retired2 has tested it for CFM efficiency but I like to see a test for fine dust efficiency. And Bill Pentz does not have a bell mouth or an air straightener. Food for thought.

really like your build.

Hi,

I want to vent outside. Has anyone tested their baffle with handfuls of fine dust and watched their vent ?  Mine fails this test but seems to be working under normal conditions.

Thanks,

Bob