www.diycinema.co.uk

[Dust2Dust]

Here is a montage of photos, showing the progress on my DIY crossflow fan, using a couple of old processor fans and a lynx deodorant can!
It is still in the making, have still to finish it, but the results are promising.
Running from 12 volts, (actual fan voltage) it seems to move way more air than the fan that provided the motor did.

I found that spacing for the fan vanes was near a prefect fit, round the tin, at a half inch, (imperial measurement, as that is the only ruler i had to hand!)
I then had to bend the edges of the vanes over, as they struck the hearth/work surface i was testing it on.
Doing that, made them stronger, and they also clear the work surface, which is nessasary? for the flow director plate also, some clearance.
Will update with new pics as progress is made.
D2D

P.S. i know it looks rough, but it is DIY, and as long as it works!

[finker]

Hi that looks very interesting! I took one out the ohp projection panel, and it didnt half shift some air!

Fan assisted cookers also use these fans I believe.

I might have to experiment too sometime!

[Dust2Dust]

You also find them in blowheaters, but they can be quite large, and loud as they run on 240 volts, my one only requires 12 volts. and is very quiet.
I have'nt quite finished it, still rummaging for the bits i need in my "might need that someday" boxes!
Will probably have it done by tomorrow.
D2D

[doug]

and i thought you were joking when you said you were gonna build this!

[Dust2Dust]

Some more pics, a slightly useless pic of some of my "precision tools" used during construction.

One of the "flow director plate" marked up on a roses tin,(good source for easy worked tin).

Last, but not least! the fan, and the flow plate, seperate, but they fit together excellent! will update later!

P.S. that's NOT bluetack, it is epoxy putty, great stuff for adhering things together!
D2D


Last edited by Dust2Dust on Fri Jul 14, 2006 6:07 pm; edited 1 time in total

[Dust2Dust]

Here is the fan working!
Only one motor is being used for driving the fan, the other has had it's circuits & magnets removed, it is only there for balance/support/bearings.
Was able to screw the side with no motor directly to can.
The arrows show the direction of the airflow, which goes down behind the can, and out from under it, (which was the hardest bit to get right.) Which all depends on the pitch and angle of the fan fins.
If the angle was even slightly wrong, the airflow changed the direction/angle it left the fan.

Tweaking was needed to keep the intake from also being an outlet for the air!
Pretty much all the directions to make one of these is in the pics.
D2D


The view from the back, showing the curve on the flow director plate thingy! (note the bicycle inner tube elastic bands!)

[doug]

Those look like some well used tools

Talk about back basics D2D, the way you come with these crazy sources of parts never ceases to impress me!

[dunc_42]

great work d2d,couple of questions .i noticed that you have cut the blades off on one fan or is it both? cant tell from pic,it also looks like you have just one of the fans powering? i assume this is beacuse it would be impossible to get both running at same speed and they would working against each other? keep up the good work keep meaning to ask is it my pc or is the home page evaporated?? cheers Dunc_

[doug]

It's not you Dunc, i'm still fixing it

[Dust2Dust]

Hi Dunc_! I have taken the fan blades off both fans, just using one for turning the can.
Yes, you are right that powering both fans would act against each other.
The other fan is there just to be the other side, and for it's hub, for balancing the fan. ( i removed the magnet and electronics from it, as well.)
Am now working on a more simple, three finned? treble bladed? tri-fanned? diet Redbull tin fan.
Will post the results.
D2D

[Dust2Dust]

Hi all, have tried to make a three finned fan using redbull can, results where not as good as the Lynx can fan.
I think that as i had the three fins connected in the center, the fan would'nt direct the air through the fan, just moved the air around the blades, and did'nt create a suction/blowing effect.
It seems that you need the center of the fan to be clear of any obstruction, so that the air gets channelled in the direction needed.
More experiments needed, i think...
As i cant seem to keep on the same idea for long, i'm not going to continue this project for the forseeable future as i'm now on the spinning liquid, parabolic reflector design thingy.
Will maybe get back to this sometime.
D2D