Thread: Dust Collection - Machinery Connections

Rev, sound like a good idea - I look forward to seeing a photo. How close is the fit to your DC and was it easy to connect?

Ok, Here is a picture of my setup. The filter stack is sealed with silicone between each filter. A dust trap is built at the bottom of the stack; it has a removable perspex front to see the dust that comes through the system and for cleaning (unfortunately not in the picture).

Cheers

No pic here!

Blow the dust off Bob and youll see it
beejay1

http://community.webshots.com/user/eunos9

OOPS! Try again...

Guys, very interesting thread........

I have recently spent hours reading the info on Bill Pentz's site...........the guy deserves a medal.

One thing I noticed was that while he does say on a number of occasions that the minimum requirements for a cyclone to be effective are a 2hp mtr fitted with a 12" impeller, he gives little further detail or instruction preferring instead to focus on 3hp/14" impeller setups. Now that is fine, BUT in the US, the mains power is 60hz which means that a standard single phase mtr normally rotates at approx., 3400rpm whereas our mains power is 50hz which equates to a standard 2740rpm (from memory), so straight away our blowers are running 19% slower than Bill Pentz's designs allow for. The obvious conclusion would be that because of this, a BP designed cyclone will never function at it's full efficiency here in Australia unless of course the impeller drive is geared to increase the rpm.

Any comments?


Regardless of being aware of the above, I recently picked up a used Hafco 2hp, 1200CFM H/duty DC from an auction for $200 with the intention of canabalising it for a cyclone blower as this unit has a 12" impeller as per BP's minimum specs., and this brings me to the next point............:

The Hafco (along with numerous similar units) 2hp DC has a 12" impeller and is rated at 1200CFM. Carbatec list 2 models of "single bag" 2hp DC, one with a rating of 1200CFM the other is 1700CFM. I have seen other brands of the 1700 unit which are only rated at 1200CFM. Somehow, I think Carbatec's specs on their 1700CFM model should be viewed with some suspicion as I fail to see how they could pick up a near 45% increase in performance without increasing the motor size.


Lastly, can anyone tell me why I am not seeing about 90% of thumbnail links in posts.............it is only occasionally that there is a "dash" in an attachment window that will let me link to a pic.

There's even another thing, unless you buy a JET brand you wont get a 14" impeller on a 3hp unit.
Your right about the 2750rpm, thats what mine runs(3hp cheapy)at with a 13.25" impeller, rated at 2000cfm at one shop 2300cfm at another shop... exactly same unit, same $$$ just different colors!(lucky its not red)
Id go as far to say it probably wouldnt suck 2000cfm even, in real life circumstances.

The 1700cfm may possibly have a bigger impeller, probably same motor it'll just be closer to its max amp loading than the lower rated unit. Still looks identical on the outside, also find things like better motor bearings and thickness of the steel used to make it with will be different, so it will last longer in constant use.

Its not that the cyclone wont work, BP likes a bigger cfm to make up for the friction loss you get using a cyclone separator, ie a 3hp would have near the same cfm with a cyclone connected as 2hp without one.

Wow, just started at the beginning and read the whole lot. Only took me about three hours. (I'm a slow reader).

One thing that people were asking about was air volume and wind speed. This is a link to an Aussie anemometer

I don't mean the anemometer is Aussie, just the site. I think the anemometer is French. It costs $100

Or you could make your own Manometer (Bill mentions these I think) for a few bucks.

http://www.science-house.org/student...manometer.html

What is a Manometer.....Quote from the site above :

A manometer measures the speed of air based on Bernoulli's Principle.As the fast moving air moves over the tube opening at C, low pressure is created. The higher pressure at A, where the air is still, pushes the water up the tube. As the speed of the air at C increases, the difference in pressure between A and C also increases and work is done on the water to push it up the tube (B).

Another link http://www.rverscorner.com/articles/manometer.html

(and No, I have not made one myself yet)

I've just read this thread right through and enjoyed the work put in by all. This is my first post to the site so please be gentle. Having recently become aware of the dust issue and read Bill Pentz' site I now intend to build a cyclone. (It was something to do with the layer of dust in the shed and the fact that I noticed how tight my chest became after a recent sanding episode. )
I was fortunate enough to pick up a second hand Ledacraft 2 hp DC yesterday so am now planning the project, looking at ducting sizes etc. Space is limited so the cyclone will have to go in the lean to firewood shed. From what I've read it looks like 6 inch main lines are the way to go.

I have some Triton gear (Router table and WC2000) and wondered whether anyone has comments on the huge difference in diameter between the dust ports on that gear (38mm or 1.5 inch) and the 4 inch branch lines that everyone seems to consider to be the minimum. I have only seen one comment about this - to the effect that you can use plumbing fittings to reduce down. But how effective is the suction when you reduce down from 6 inch to 4 inch to 1.5 inch? Does this mean that I will also need to build hoods for everything?

I'm not afraid to do the work - but I want to plan.

Welcome aboard Tomcat.

There are quite a few threads on connecting DCs to the Triton gear under the Triton forum section of this board. The best ideas involve modifying the DC connection to allow larger pipes - do a search an you should find them.

I have only a 1hp unit with 4" PVC pipes, but used a sheet metal taper to the 2 smaller pipes for the router table (see http://www.woodworkforums.ubeaut.com...ad.php?t=19657). Be careful to ensure there is enough airflow to your DC or you may restrict the intake too much and burn your motor out (Bill Bentz also talks about this on his site) - ie don't just reduce a 6" pipe down to a 1.5" intake.

Cheers

dai sensei, its the oppisite its when there's not enough restriction that the motor goes under a harder load... because its moving more air, put your hand over the end of a vacuum cleaner hose and the motor will speed up because theres no load to slow it down, ie your vacuum cleaner works its hardest with a clean bag!
Thats why BP gets into measuring the load of the motor when making the inlet to the impellor larger to make up for the friction loss assicated with adding a separator/cyclone, he say's that most manufactorers purposely leave the inlet hole smaller so the motor doesnt burnout when the is no ducting conected... and make cheap motors last.
If you measure your motor amperage under load you'll probarly find the motor is only using about half of its amperage capability.

Anyway to unhyjack this thread(" Dust Collection - Machinery Connections")
I made up a connection today for my Tsaw tennon jig because you cant use a overhead guard with draughting.
Just a bit of a 102mm pvc attacked with a heat gun, couple of screws and yehaa bobs me uncle!

Yike harry those wood chips don't have a chance.

If I was a wood chip comming off that blade I'd be afraid very afraid. :eek: