Home made Cyclone - what am I doing wrong?

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Forum topic by Absinthe posted 06-25-2011 03:40 AM 3192 views 1 time favorited 17 replies Add to Favorites Watch
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90 posts in 2557 days

06-25-2011 03:40 AM

Other than neglectng to wear gloves, what am I doing wrong?

I worked out all the angles and made myself a wonderful story-stick-trammel and cut out the cone part. So far so good. Aviator snips are not really much of a woodworking tool, but I can handle them ok.

So I have this lovely flat piece of a part of a circle and now I have to ‘roll’ it up. I grab every round thing in side and try to ‘roll’ it around. It has formed creases and crumples all over the place but it certainly doesn’t look like all those smooth nice funnel cones I have seen everyone else post.

Granted, I am not using 30 gauge, but more like 24 gauge. Sure enough this stuff does not want to roll smooth at all. I assume there is a tool out there that professional metal type people use to roll and form metal. Let’s assume I do not own one of them :)

Right now, I have simply tacked it together with a screw at the top and bottom.

Pictures are attached.

-- Absinthe

17 replies so far

View D_Allen's profile


495 posts in 2810 days

#1 posted 06-25-2011 02:08 PM

Build a Thien separator…it is easier!

-- Website is finally up and

View Chipy's profile


374 posts in 2619 days

#2 posted 06-25-2011 02:32 PM

I respect the fact that you want to build one your of your own.I looked into making one thees myself but I have never been good with sheet metal so I just bought one from Oneida air systems and it works awesome! I think it was about 50 bucks.

View Don W's profile

Don W

18754 posts in 2593 days

#3 posted 06-25-2011 03:36 PM

I bought the premade cyclone separator. I was in a hurry and its $26. I figured I would use it until I had time to build a good one. I modified it a little to sit on a 55 gal drum since I had one. its so simple it isn’t funny. What you see is what you get. There is nothing underneath, BUT, to my surprise it works fantastic. I’ve since upgraded my dust collector to a 5 hp model, and I still use it. My suggestion, for $26, buy one. If I’m wrong, well, I’m not. :-)

-- - Collecting is an investment in the past, and the future.

View Absinthe's profile


90 posts in 2557 days

#4 posted 06-25-2011 03:52 PM

I already have the oneida on order. I am concerned that it will be too small foresee with 4 or 6 ” piping. I am also planning on doing a Thien separator as well. I have some ideas I can only trywith a working one.

That said, I am still interested in some advice on how to smooth my cone without a slip roller. Since I have already begun making the thing, have to finish on principle even if I don’t use it. I also have an idea cone formation that can work with a pre existing column shape as a starting point (think stockpile) that could possibly form both the top straight as well as the cone already connected.
But I digress. How to smooth this ugly beast?

-- Absinthe

View Damien Pollet's profile

Damien Pollet

73 posts in 2635 days

#5 posted 06-25-2011 04:06 PM

I’d get help from a cylindrical shape, like a broomstick or a rolling pin, or the rounded edge of some table. Maybe with a soft mallet you can beat it into a better shape.

I don’t think it’s really necessary that it’s a perfectly smooth mathematical cone. The metal surface is plenty smooth enough, and the visible ridges don’t really matter… just try to round the big flats by making more evenly-spaced ridges in them, so the section looks more like a hand-drawn circle than a peeled potato :)

View bigike's profile


4052 posts in 3314 days

#6 posted 06-25-2011 04:17 PM

Me personaly I don’t think it’s to bad it’s only gonna collect dust through it and it looks smooth enough for that.

-- Ike, Big Daddies Woodshop,

View Bluepine38's profile


3379 posts in 3111 days

#7 posted 06-25-2011 04:51 PM

I tried one of those plastic lid separators and the dust would not stay in the garbage can after it was about
1/4 to 1/3 full, so I built a Thien system for the garbage can and another for my shop vac that I can also use
with the 2-1/2” line from my big dust collector. Both work great.

-- As ever, Gus-the 79 yr young apprentice carpenter

View Absinthe's profile


90 posts in 2557 days

#8 posted 06-25-2011 05:02 PM

Thanks.. it will ne a week before I can play with of again. I will try something thin and round.

-- Absinthe

View ptweedy's profile


75 posts in 3419 days

#9 posted 06-25-2011 05:17 PM

hey guy get a piece of pipe hold it in the vice horizontally slip the cone onto the pipe, beat until done. phil

View EEngineer's profile


1103 posts in 3639 days

#10 posted 06-25-2011 05:29 PM

I have formed things like this in sheet metal by using a 2” round (part of an old handrail) and a rubber mallet. Run the sheet metal over a round form and beat with the rubber mallet. You don’t have to go crazy, just soft strikes with the rubber mallet to gradually curve the sheet metal. Move it about an inch at a time to overlap strokes and gradually curve the metal into a circle. You don’t even have to match the final curvature, if you get it formed into a general curve it will bend tighter without “crinkling” (is that a technical term?).

-- "Find out what you cannot do and then go do it!"

View Don Johnson's profile

Don Johnson

686 posts in 2806 days

#11 posted 06-25-2011 09:58 PM

You may find that if you heat the metal to near red, and let it cool naturally, it will soften, making it easier to form.

As you form it, it will work-harden, so repeat heating may be necessary.

-- Don, Somerset UK,

View Don W's profile

Don W

18754 posts in 2593 days

#12 posted 06-25-2011 11:46 PM

That’s weird. I have filled my barrel to the top, and then the debris will head to the dust collector if I don’t catch it. I wonder whats different. Think the 55 gal barrel makes a difference? The plastic lid works great for me, and I was surprised. I really didn’t expect it to.

-- - Collecting is an investment in the past, and the future.

View Absinthe's profile


90 posts in 2557 days

#13 posted 06-26-2011 07:43 PM

I will take some pipe from one of my pipe clamps and put it in the vise and see what the rubber mallet will do for me. I think I will get some gloves first though.

I wonder, however, why this wouldn’t ‘roll’ up per se. Even when the full sheet was in hand I tried to roll it into a circle and even a 4’ span didn’t want to roll up. Is this an attribute of some metals over others? Or is it simply the gauge?

One of these days me and Mr Gingery will build a slip roller, but until then the rubber mallet will get some use :)

I have some thoughts on a Thien separator, but I will do that in a different thread.

It is frustrating to be on vacation away from the shop when I am at this point in a project :) But a bad on vacation… :) Weather is great, ocean is nice and life is laid back… I have no complaints. :)

Thanks for all the suggestions. This will be a fun project if it works it is even better. I guess wood, metal, whatever, it is all creation and that is what I like.

-- Absinthe

View matthess's profile


2 posts in 2706 days

#14 posted 06-26-2011 08:26 PM

Hello Absinthe

I built a Bill Pentz cyclone, and I my first cone looked quite the same. I tried again with sheet metal that was a bit thinner. 0.6mm works great, it is stiff enough and will not collapse, yet is easy enough to bend.

How thick is your sheet metal?


View Absinthe's profile


90 posts in 2557 days

#15 posted 06-26-2011 08:55 PM

Hi Matthias,

The sheet metal I have is 24 gauge which should be .511 mm.

With the top circular part and the sealed cone, I can imagine that even fairly thin material would not be likely to collapse but that is just my uninformed opinion. I even wonder how well a stretched cone would do. Something like a tepee with outside posts and some tough material inside.

Anyway, did you build the 6” (vacuum recommendation) one or the 18” (5hp recommendation) one?

-- Absinthe

showing 1 through 15 of 17 replies

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