New cooling fan setup

Here is a poor photo of my cooling fan setup. The meade mirror cell had a 3" hole in the center, so I cut a circular mounting board with a router and attached it to the back of the cell via the 3 collimation locking screws that were next to the traditional spring screws. I cut a 3" hole for the fan and 4 mounting screws in the back of the plate. You can see the red on-off switch at 12 o'clock, then 25 ohm poteniometer fan-speed control at 4 o'clock, the mono headphone power-jack at 8 o'clock. The 3 collimation screws are at 2-6-11 o'clock, and you can see the 6 counterweights around the plate to offset my heavy university optics focuser and finder. The fan is held by 4 thumb-type-screws so it can be removed and flipped over in about 2 minutes. This way I can experiment with the fan either blowing up the tube or down the tube. So far I have only used it with blowing air down the tube and out the back. All the parts were purchased at Radio Shack. I cut a vibration-isolater pad out of a black Best-Buy mouse pad which is sandwiched between the wooden plate and the fan. So far I have not seen any vibration at 250x at any fan speed, 250x right now is my highest power. All of the components on the plate are "inside the tube" so if I happen to set the tube up on the mirror cell end, none of the components will be damaged. (nothing sticks outside the tube)

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Very cool Steve.

I want to do this on my 10" which also has a hole in the middle of the mirror cell. Problem is that I am not an electronics guy so I have now idea of what parts to buy from radio shack or how they go together.

Would you be so kind as to give me a list of what your setup uses parts wise and maybe a little diagram on how things get attached?

I would appreciate it.

Thanks,
Scott

Very nice, Steve. What's the aperture?

When you compare blowing in/out be sure to post your results. I'm considering a similar setup in my next scope.

Thanks for sharing,
Doug

I went through my notes and found the parts list for my cooling fan setup. All are from Radio Shack.

3" 33CFM, 1.92 watt, .16Amp draw fan #271-265 $18.00
25 Ohm Rheostat, 3 Watt, #273-243 $4.00
On-Off switch, 3 amp, #275-011 $2.50
Knob for rheostat - #274-416 $3.50 (4 in a pack)
1/4" Mono Headphone Power Jack #274-255 $4.00 (2/p)


So just $30 in parts. Need to buy some wiring, and soldering parts too. But I already had that stuff.

Also note, the counterwieghts have no effect on the mirror or seeing, they are "outside the tube".