Where abouts can you buy cheap thin aluminium sheet?

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vtsteam:
Suggestion -- get yourself a length of pipe about 35 to 50 mm dia. and drill through for bolts at both ends. Attach to the edge of your workbench and space it with a washer out so you can insert your cone blank between the bench and pipe.

Then you can pull on the sheet to bend a small amount gradually lowering it into your bending vise as you do successive pulls. You can also tap with a hammer to do the tight end of the cone if needed. To get even bending, draw radial guide lines on the cone blank, because one end needs to be bent faster than the other. Don't try to bend all in one go, do a few passes through your bending vise to keep it even and avoid hard spots.

The ideal simple sheet metal setup (if you have wooden benchtop like me) is to let a piece of heavy angle iron into the edge of the benchtop, so you have a sharp corner of steel there. Drill and tap it to accept bolts at convenient spaces and make matching clearance holes in another similar loose piece of angle iron, so they can be bolted together, like a very wide Tee shaped vise. That will work to make sharp bends in sheet metal. Substitute your pipe with drilled holes to make round bends.

You can also use your pipe as a long anvil if you hang one end from a U shaped strap on the bench or wall, and support the other end in a temporary post. You might need a little hammering of your cone blank after curving with the bending vise to get a smooth bend in the start and finish edges, rather than a flat spot.

dsquire:
Steve

That is a great idea, the pipe in the vise. With a carefull eye and a skill full hand on the hammer you could have most any size cone you want. :D :D

Thanks for that one Steve.

Cheers :beer:

Don

S. Heslop:
I did something that in the past to make my sheet metal forge (even got a video of it. My earlier videos send me to sleep...). I think you mean pulling it through all at once though, kinda like how you curl paper strips up?

vtsteam:
Nope, Simon, I do mean making a small bend at a time and shifting it and making another. It isn't a slip roll (bending rolls). The pipe is stationary, not rotary and you don't slide the blank over it while applying bending pressure. Think of it as one jaw of a vise, and your workbench top edge as the other. The bolts go into the pipe crosswise to attach to the bench top -- not axially like a roller.

While it sounds like doing it that way would create a faceted bend -- or series of bends -- it is actually surprising how smooth you can make it. Just don't try to bend too much at once. I like to move the metal back and forth -- kind of a wiggle, feeling for the amount of bend.

I don't know your cone layout and how small the small end is -- I assume it is truncated with a pipe at the bottom and an unloading hatch of some sort. But anyway, the small end might require some light hammering (just tapping a tiny amount forward of the pipe to blank edge) to get it to bend -- all depends on the feel. You'll know when you do it.

caskwith:
Are you making this as a project (ie the making is part of the fun) or are you just wanting a cyclone for purely practical purposes?

If it's the latter I can heartily recommend Cyclone Central, I have 2 and they are brilliant and there is still some assembly to enjoy in the process but you know the end product will be good and not a waste of time and money.

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