Thread: My Cyclone - WIP

This cyclone was fun to make, and I learned some new techniques. Total cost? Not real sure but some items were:*
2 x bins @ $10 ea = $20
1 sheet polycarbonate = $24
MDF, pine, foam, stormwater pipe, screws, bolts, silicone glue = $50 (bit of a guess)

*Note: time not costed:eek:

All up, about 100 buckeroonies.

Some promised attachments:

1. The plan I worked from. The only change is the direction of swirl, and some of the seal detail. The direction of swirl is determined by the placement of the inlet to the top chamber, and the overlap of the glue joint in the cone should be consistent with the direction of swirl: the air should encounter a step down, rather than a step up, to minimise turbulence. (If you really want to be fancy you could do a butt joint with a reinforcing strip glued onto the outside.)
2. A spreadsheet to calculate the cutout for the cone. This is corrected from the version I used, which had forgotten the pythagoras bit (the top and bottom diameters were OK, but the height was a bit off). In this sense, it is untested, but should be OK. I suggest testing with a piece of paper to scale beforehand.
   
   The inputs are the three values in blue at the top, r1, r2 and h. The outputs are the three values in red in the middle, R1, R2 and the angle. The green numbers at the bottom are x,y-coordinates that help in laying out the cone. You have to add your own extra to allow for glue overlaps and the folding tabs that I used to fix the cone within the sealing rings.

Great stuff Zenwood, I've archive all your pics to help me when I finally built such a beast - great work.

In your costings you didn't mention the impeller? - seems like it was built for the job. Did you buy this for the project it so where did it come from.

Cheers - Phil

Excellent Zenwood,

I'm going to build one of them for sure in the next month or two. How easy is that!!! (Now that you have doen all the hard work.)

What size extractor do you have and how much fine dust is getting into the dust bag on the impellor?

Growl

Thanks greenie and growl. The impeller I've had for the last couple of years, originally bought from Timbecon, but checking their website they don't seem to sell it any more. It was a single bag, floor version of this one selling for the same price ($180). Including the empeller, the cyclone is still good value compared to the bought ones at about $1500.

Consensus seems to be that 1hp is too small for a cyclone, but I'll stick with this for a while and see how I go.

Does anyone know, if I have to replace it with a 2hp version, if it's possible to just buy the impellers without the bag, frame, and other dust collecting paraphernalia?

Don't know how much fine dust is getting through. After a couple of runs through with the test dust, I couldn't feel any crumbs in the bag, and visual inspection of the lower cyclone bucket revealed quite a bit of fine powder. In any case, the bag is not a particularly fine filter, (the link above mentions 35 microns), and would let the really fine stuff through. I might know more after some extended use (only switched it on last night long enough to take the piccies).

My eventual plan is to dispense with the bag, and vent the outlet to the outside. This would solve the problem of collecting the fine dust, and at the same time decrease the flow resistance and increase the flow volume per minute.

I don't know if there is an Aussie supplier but noticed these on th the Penn Industries site: -

http://www.pennstateind.com/store/mb.html

Zenwood,

Excellent work.

How stable does the cone seem when in use.

Would like to build one for a 2hp impeller that I have but am a bit concerned about the cone imploding under the extra suction.

Originally Posted by zenwood

1. In the meantime, there is the problem of what to do with the bunnies bin lids.
2. Space helmet?
3. Space shoes?
4. Hmm: shoes seem to be popular.
5. Mickey mouse ears?

Plant propogators..

Well done Zenwood. Love the clear cone to enable you to see the shavings and dust, and I'm sure your kids love watching them spin.

From looking at your plans it appeared you kept the intake to the blower at 100mm. I increased the sucking power on my 1hp unit by increasing the blower intake to 125mm and tapering down to the cyclone outlet. I have it connected to a lot of pipework though to ensure I have enough resistance to avoid the blower burning out.

Cheers

Originally Posted by mag

... am a bit concerned about the cone imploding under the extra suction.

G'day mag; thanks.

The cyclone is very very solid. While switched on I can push against the sides quite hard without it distorting at all (localised pressure will tend to distort much more than evenly distributed atmospheric pressure). The ring clamps and the glue joint are very strong.

The plastic bins would implode much more easily than the cone, and even these seem very adequate. If they looked like giving way, you could glue some vertical ribs to the outside. I thinks other people have used wheelie-bins (inherently quite weak) in 2hp systems, without mishap.

The pressure is not that great: these pumps rely on low pressure, high volume airflow.

G'day Neil: Yes it's 100mm throughout. I didn't want to mess with the impeller intake -- I figured it's designed for 100mm and let's leave it at that.

What's the issue with burning out? My motor has a little cooling fan on the end (the white blades are visible behind the grill on
http://www.woodworkforums.ubeaut.com...6&d=1139527548
that blows air over itself). Would this solve your concern?

Originally Posted by zenwood

G'day Neil: Yes it's 100mm throughout. I didn't want to mess with the impeller intake -- I figured it's designed for 100mm and let's leave it at that.

What's the issue with burning out? My motor has a little cooling fan on the end (the white blades are visible behind the grill on
http://www.woodworkforums.ubeaut.com...6&d=1139527548
that blows air over itself). Would this solve your concern?

Mine has a little fan also, but I don't think the fan would help the problem, it's more about the current drawn by the motor. From Bill Pentz's site - "Air coming into the blower is controlled by the size of the blower opening. That opening needs to be carefully sized to allow full airflow without restriction or we lose considerable performance. Additionally, that inlet needs to be small enough that we never get into an open air situation where the blower motor tries to push so much air it quickly burns up. Likewise, the blower outlet needs sized carefully to not also add performance killing resistance." Certainly your approach of sticking to 100mm is the safe option.

Cheers

Great job Zenwood, I love it. What's the stability of the whole unit like given that you have a great chunk of cast iron sitting up the top? I understand you intend installing the unit in your adjacent shed and so you can probably tie it to the wall for safety if need be.

Also, is the bonding of the entry pipe into the bucket quite strong using silicon? In your opinion would liquid nails give a stronger bond or is it not so good with plastic?

Clearly you have set a new standard for achieving a great result at a very low price. Well done.

Regards
Trevor

G'day Trevor: thanks

The stability was a concern to me; as you mention, it is quite top-heavy, but in use there's not much trying to tip it over, just some torque on startup, and a bit of vibration, which doesn't seem too severe. I just have to be careful when moving the unit from place to place. I will dismantle the top before the move to the old shed.

I did a test with liquid nails on the polyethylene (the blue buckets), and it was hopeless: just popped right off, even when the surface was sanded beforehand. The silicone is much better, and seems quite solid in conjunction with the wooden support on the frame.

I'm keeping the cyclone in the main shed for a while to assess its reliability and overall performance before committing to the effort of putting it in the adjoining shed. For example, the bottom wedges were cut at too steep and angle, allowing them to work lose, and losing the top seal. I may end up changing this system. Will keep this thread informed if I do.

Boy that looks like it sucks ! ! !

Great work there Zen,
Have you a baffle or valve so that you can muck around with the "cut point?"
We use cyclones at work to separate slurry's, the density of the product and the slurry water are very similar, got to get the "cut point" spot on, or over the top it goes.

Like your excel spread sheet, are you a mathematician???
Cheers Gary