Starkler I've actually got the fan running in reverse.. drawing the air out.. i figured it'd suck the air through the front of the tube. I didn't really want to blow air up the tube cause it might blow dust and stuff up the tube which would then fall and settle on the face mirror. I've used a bit of paper to test it out and with the fan on there is the slightest bit of movent of air going from the front of the tub down towards the mirror.. which is what i was aiming for as i didn't really want a huge gust. The hole is acutally square, with four triangles cut out to make an 'X' in the middle to mount the fan, which is a 120mm Antec fan.. i initially went with an 80mm fan.. but then i though i'd get abit more air movement for a lot less revs(and noise!) with a 120mm.. and it only cost $19 so it was sweet
I used a dremel to cut the holes
Next step will be to ad some protractor marking thingy's.. are they called setting circles???
then if the rain and clouds still don't break i'm gonna have a go at making an electronic focuser, with a hand control unit, which will be based on a jaycar stepping motor kit which retails for about $50..
i think i'll just have to keep telling myself.. we need the rain.. we need the rain.. we need the rain..
el