Variable speed mirror fan - Page 2

matt · #21 02-05-2006, 06:44 AM

Wow. Well, there you go. Your images are a glowing testimonial to natural (passive) cooling and favourable ambient conditions.

Should be interesting to see what, if any, improvement a fan and temp experiments bring to your images.

Good stuff

iceman (Mike) · #22 02-05-2006, 02:50 PM

Ok, I went to d.ick smith at lunch today and picked up some goodies.

Got this 9cm 12v rotary cooling fan for $20.

I asked them for a variable control box, but they didn't have any. This power house store wasn't as big as some others I've been to in terms of electronics gear, so i'll try the one close to home and see if they have it.

Where did you get yours from Matt?

How is it powered?

How is it wired up to the power and the fan?

davidpretorius · #23 02-05-2006, 03:05 PM

bunnings sell aluminium sheet that is .6mm that you can quite easily but into a disc if you want to seal the bum of ya scope

matt · #24 02-05-2006, 03:07 PM

Here you go Mike.

http://dseau.resultspage.com/search....1.x=11&I1.y=10

I run mine plugged into a SkyWatcher 17Ah 12V powertank which I bought from MyAstroShop.

Cigarette lighter adaptor plugs in to Powertank ... other end plugs in to base of DC Motor Controller Kit using a socket I also bought from D.Smith and wired to the controller kit's circuit board.

The black plastic box housing the motor controller kit is bought separately. You just need to make a few holes for the speed knob, the power-in plug and the wires connecting the fan to the controller kit.

And Bob's your mother's brother!!!!

Hope this helps

Orion · #25 02-05-2006, 05:02 PM

Well done Matt with your fan, I'm just wondering can you use one controller to control more than one fan?

matt · #26 02-05-2006, 05:33 PM

Not sure Ed?

Would that not increase the load through the controller and cause a few probs?

Wouldn't the fans possibly not get the volts they require?

Worth an experiment.... for another time

gaa_ian (Ian) · #27 02-05-2006, 10:16 PM

Thats great Matt, do you have the Catalog numbers for the DSE components you used ?
I buy from DSE all the time online & have an account so I get good prices.
This would be good for my 10" dob in the dry season!

RAJAH235 · #28 03-05-2006, 12:32 AM

Ed, fwiw. The 12 volt fans run on around 170 mA, so you could use 2 or 3 fans with no trouble on the one PWM controller. BUT, because of their diff characteristics, you might find that one requires more 'power' than the others. (do a bench test to see if they all run @ about the same speed setting).
Just watch the total 'on' time tho, if battery is also used to power your t'scope. (Best with a separate battery).
HTH.

L.

iceman (Mike) · #29 03-05-2006, 05:56 AM

Ian, the catalogue number for the controller is K-3070 (in Matt's link).

The catalogue number for the fan is in my link above.

matt · #30 03-05-2006, 05:59 AM

Just beat me to it Mike!

By the way, how'd you go? Did you get the speed controller kit?

Orion · #31 03-05-2006, 07:49 AM

Quote:

Originally Posted by RAJAH235

Ed, fwiw. The 12 volt fans run on around 170 mA, so you could use 2 or 3 fans with no trouble on the one PWM controller. BUT, because of their diff characteristics, you might find that one requires more 'power' than the others. (do a bench test to see if they all run @ about the same speed setting).
Just watch the total 'on' time tho, if battery is also used to power your t'scope. (Best with a separate battery).
HTH.

L.

Thanks for the info Laurie,

This is the configuration of the fans that I am planning on using the controller on.
There are three 4cm fans and one 12cm.
I'm guessing I might need two separate controllers?

iceman (Mike) · #32 03-05-2006, 08:02 AM

Quote:

By the way, how'd you go? Did you get the speed controller kit?

Will check DSE again today.

Quote:

Originally Posted by orion

This is the configuration of the fans that I am planning on using the controller on.

Wow Ed, that looks great! Is this to go on your 18"?

Orion · #33 03-05-2006, 08:07 AM

Quote:

Originally Posted by iceman

Wow Ed, that looks great! Is this to go on your 18"?

A 24" Mike that I am in the middle stages of designing.

matt · #34 03-05-2006, 08:08 AM

Oh yeahhhhhh!!!

That'd certainly be a little too much puff for my 8" newt!

iceman (Mike) · #35 03-05-2006, 08:08 AM

Nice!

iceman (Mike) · #36 03-05-2006, 01:42 PM

The DSE here doesn't stock the K-3070, but it is at the Gosford store (near home), so i'll go and get one soon.

astro_nutt · #37 03-05-2006, 04:09 PM

I opted for the "make it out of whatever" method..until I have the proper stuff..I used packing tape to secure a 3 volt motor onto a 30cm length of heavy duty electrical wire then secure this with more packing tape to a lantern battery..I found a fan from an old hair-dryer...attach this to the motor..a clothes peg for the switch...and it works!!..I just point the fan to the primary and remember not to move the scope while I have it going!!!...cause it does make horrible noises if you do!!
I like the idea of have a variable speed fan though..
Good one Matt!!!
Cheers!

stringscope (Ian) · #38 03-05-2006, 08:09 PM

Hi Matt,

That is a really nice neat and simple mod. Well done!

Cheers.

matt · #39 03-05-2006, 08:17 PM

Thanks Ian.

And you've just reminded me it's almost time to renew my CAS membership and also to give you a much belated call to get together and check out those Konigs in my 9.25 and just generally catch up

stringscope (Ian) · #40 03-05-2006, 09:25 PM

Hey Matt. I thought you had lost interest in the Konigs!!

Yes, Shirley will be chasing us for our CAS membership renewals pretty soon.

Cheers,