Thread: Hafco W318 dust extractor.

I'll check the blade height after work today, i think the impeller is 300mm=12".

Cheers
Hoey

Just looking again at the picture of the housing you posted, the tape shows an opening of 300 mm, so the impeller is smaller than that, you may be correct at around 12".

In comparison the impeller in my DC is 366 mm tip to tip and the opening is larger again around 390 mm from memory.

You have 7 fan blades, mine has 8 blades and the shape and construction are different, yet from a distance they look exactly the same DC, clones of clones I guess, I have a suspicion from searching the net that the original design was the UFO-102B which is what mine is. It's entirely possible that your blade height is greater and has a more aggressive shape that gives it good air flow at the expense of a higher noise output. Look forward to seeing how high the blades are.

Here are the pics, Mike.

So basically close to a 12" impeller, the blade shape is totally different, mine have a big taper, of course much wider and I feel less aggressive, but having never bothered about blade design and effect I'm only guessing here. In lieu of someone in Melbourne having the correct flow meter and the knowledge to use it correctly, Wish I was close by, as I'd love to know how much current it draws with a naked input and also test current with no bags, along with AC voltage at the time under load, that would at least tell us the input power.

Measuring closed port static pressure and open port static pressure would also give a bit of an idea of what you have to play with, but as the gurus will point out, nothing beats actually measuring the flow rate.

Hope this is not taking you to far off the topic of your workshop build, if so pleas say so.

Mike.

Oops, forgot pictures in last post.

Hi Mike, i have stopped any progress on my dusty system since yesty! I really want to know what is the low cost and promising solution that you know, hopefully it will work for me so i can be on way to be a woodworker

Cheers
Hoey

Starts at post #20 Beginner attempt at DC - thanks to forum members

This is testing the top part of one of those cyclones you were going to use, because flow rate is roughly halved between each cyclone on the split outlet, the loss in pressure is far less.

The idea is to make a larger unit for each side and do away with the bags.

You loose the advantage a single big cyclone gives you when mounted on the intake side of a DC, that is, large pieces of material don't make it into the impeller. In your case you still have that metal screen across the impeller housing intake, that will eventually clog unless it's removed. Instead you place removable screens at each intake port.

If this idea works out it can be retrofitted at a later date, so there is no need to stop your installation. The only other real option is a correctly made big cyclone with larger motor and 15" or 16" impeller, or clean the dust bags often.

Here is what i've been doing for the last 7 months, setting up my little woodworking shop in the garage and i keep half of the w318!




Yep, making a Bill Pentz cyclone

Didn't know that woodworking is a BIG rabbit's hole!



Top cylinder and inlet soldering up (don't no of the soldering is any good but it seems to hold together )

Inside with air ram.

Almost there.

Mind you I never solder anything til now.

Bottom ring for the dust bin, no gap b4 soldering.

Good work Hoey,

Wherever you have hard edged rings that air has to flow past consider running a round over bit over the hard edge or adding a a rounded over ring of MDF to help reduce the turbulence.

This applies to both inlets and outlets.
Here's one we added to the mens shed CVMax impeller

CVMaxBmH3.jpg

.

On it's trial supporting frame and half of the W318.






Useless cone became useful for mating dust bin and cyclone.

Bigger intake for the impeller

Uh Oh, it looks like you haven scaled the impeller housing (let alone the cyclone) to suit your impeller size and motor power.
This will profoundly affect the performance of the impeller which will in turn affect the performance of the cyclone.

To avoid disappointment I suggest before you do any more I would get the impeller working and measure its static pressure in a stand alone mode.
If you don't generate enough pressure you just won't generate enough flow through the ducting and the cyclone will not separate the dust properly.
You will need at least 8" of WC pressure to generate enough flow in the ducting pipe.
Then the cyclone itself will require at least 2.5" of WC pressure which leaves even less air flow.

I'd also have a current meter on the impeller motor when you first turn it on as it might draw too much current and damage the motor?