MechMate CNC Router Forum

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-   55. Dust Management (http://www.mechmate.com/forums/forumdisplay.php?f=74)
-   -   Blower Power (http://www.mechmate.com/forums/showthread.php?t=970)

javeria Wed 10 September 2008 08:05

Blower Power
 
HI G' what the HP rating of the motor on your dust extractor? Does Sean use the same dust extractor for both machines , yup I have seen one of your's in the dust room - I am assuming you atleast use a dust extractor to clean the machine in the dust room.

Gerald D Wed 10 September 2008 09:44

1 Attachment(s)
Only the one machine has a dust collector - the one in the room is soaked in dust.

The collector is the standard Chinese 2HP unit sold under many names and produced in slightly different flavours from more than one factory:


Our one was stripped down and got its motor/fan section turned horizontal and fixed to the wall.

javeria Wed 10 September 2008 11:12

I just ordered one to be built here cost me somewhere like 300USD for a 1 hp, I am asking him to revise it to 2 HP, it will be a good one bcos I am making the drawings for it.

The impeller back plate is 8mm mild steel plate 300mm dia and 3mm thick plates for the blades. The whole casing will be 1.5mm thk, the motor will also be a 2 hp indian make called LHP - all this bcos this is the company where I had worked earlier as a Design / erection / material /process engineer :) http://www.devakireinforcedplastics.com

and the whole setup will look something like yours!

RGDS
IRfan

Gerald D Wed 10 September 2008 11:47

Okay Irfan, let's see if you paid attention during Fluid Dynamics classes . . .:) . . . .

Your "wheel" is 300mm diam, how "thick" is it? (how tall are the blades?). How many blades?

How did you calculate those two parameters? (the 300mm "feels" a bit small for 2HP at 2900rpm). Do you have a current meter (amp meter) to see if the wheel size is correct for the motor?

A typical approach is to make the wheel a bit too big so that it draws slightly too much amps, and then choke the inlet to drop the amps. If you weren't paying attention in the Fluid Dynamics class, you will believe that choking raises the amps.....it does not. :)

javeria Thu 11 September 2008 06:41

Gerald, you guessed right - I hated Fluid Dynamics - never got what it was into my head. Just read thru the text and memorised to get thru the exams.

I was just going by sizes of some of the standard blowers. The number of blades may be 6 and height of the blades would be around 60mm. I had a book with those calculations. I will let you know the exact next week.

Thanks for the hunting - it keeps us on our foot G'

:)

Gerald D Thu 11 September 2008 07:07

Have a long lazy read of this long page http://billpentz.com//woodworking/cyclone/Blower.cfm to get a feeling of some of the things involved. Realise that Bill Pentz is from the the 60Hz world where motors turn faster than in our 50Hz world - we need bigger diameters.

javeria Thu 11 September 2008 09:28

Had been reading the website till now, the 14.5inch impeller has all the dims but rated for 5 hp, Will settle down for a 13.5 inch dia thats approx 350mm dia,

good reading, probably will drop the order the blower and build the cyclone instead, will cost almost the same.

Thanks G' I had almost forgotten about Bill's website.

I will use the calculator to determine the exacts.

RGDS
Irfan

liaoh75 Thu 18 September 2008 10:15

I'm a bit embarassed to even ask but what would be the functional difference/benefit of the traditional dust collector vs cyclone?

domino11 Thu 18 September 2008 10:49

As far as I know the cyclone will filter out more of the larger particles before it gets to the blower and final filter. Makes the final filter more efficient and easier to clean.

javeria Thu 18 September 2008 18:43

cyclone explained
 
Take a look at his site - you can do it on your own!

http://www.ablett.jp/workshop/cyclone2.htm

Doug_Ford Thu 18 September 2008 20:23

David,

I believe my cyclone\dust collector filters out 1/2 micron dust. Have you been to Bill Pentz's site? You should be able to google it. Lots and lots to read. Greg J and I bought systems that were based on his design and I'm very happy with it. I believe Greg J is too.

Greg J Fri 19 September 2008 16:47

Extremely happy with my setup. Easy assembly and setup. So much air flow, that no front end is needed on my DC Foot when cutting MDF.

Cutting PVC is a different story. Hugh chips fly and a front shield is needed. :o

Red_boards Mon 27 June 2011 19:02

Looking at this 3HP dust extraction system
 
I'm looking at this system for dust extraction. It's actually under-specced according to info on Bill Pentz's site, but I can't afford the next size up (about 3x the price).
it's nominally a 3hp motor driving a 12" impeller, alledgedly moving 2800 ft3/min. If I'm cynical about published specs, I would say the motor is probably 2hp RMS and air movement 1200 ft3/min at the machine (rather than the extractor ports) which, together with the small impeller, means it's about minimum spec for a one-car garage workshop.
I'll get around to building myself a "proper" extractor a bit later.

http://ledamachinery.com.au/catalogu...products_id=50
There's also a smaller model, similar to the one Gerald posted earlier:
http://ledamachinery.com.au/catalogu...a8c3fde645a857

I'm considering building a dust room. This should help with cutting noise, too.

MetalHead Mon 27 June 2011 19:34

Shoot Build the whole extractor. You mentioned the God Father of dust removal so I am sure you spec'd it all out. Rad Racer built one.

Here

http://www.mechmate.com/forums/showt...92&postcount=1


Man have I said this week how much I love this site !!!

KenC Mon 27 June 2011 21:20

I abide as much of Bill Penz's advise on dust management. Particularly the HP. What we really want is to protect our lungs from the fine dust which does the most damages. If you are blowing the air outdoor, you don't need the filter bags (yes, legally).
When I learnt that local dust collectors are going at around less than 400usd, I dropped the idea of building my own as a motor will cost about half of that locally...
When I shop for mine, I did specifically look for a 15" impeller with at least 3hp motor & a price tag which I can afford.
To keep heavy wood chips & other debris from getting to your fan impeller, You can also build a Thien separator in place of the real cyclone separator. I added an extra barrel for rotation, works wonders to keep the dust out of my lungs & every imaginable corners in the shop. takes only a few hour to build. http://www.mechmate.com/forums/showt...&postcount=349
If you are really strapped with cash, you can also build your own fan. The most important bit of the fan is the impeller. I do remember someone in this forum build his own fan impeller. Do check out Bill Penz's site, you can learnt everything there is in dust management.


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