Question about a stir plate build

I believe the biggest problem people have is with the rheostat not working correctly or getting hot when you throttle it down. Hopefully some of or engineers will give more advice.

On the bright side, a cigar box will give you a little extra shelf room so you can upgrade to a 5L flask. Just make sure it fits in the fridge.

 

i had the most trouble matching the r-stat to the fan.
you can't use an AC dimmer switch for a DC fan. that is what the rheostat is for, think of it as a DC dimmer.

i did spend some time googling matching rheostat to control fan, or something. and was lucky to have a nerd at Radio Shack that knew the correct r-stat as well.

Good luck.

 

you can always take advantage of Radio Shacks generous "rental" policy.

not the right R-Stat? return it.
Cheers.

 

Just buy 2 sachets of dry yeast for a 5 gal batch of lager or high gravity ale until you feel like perfecting the clusterfuck : )

 

Judging by a few of your comments, I would suggest to you to seek further research before diving in on this project. Not only is using just a rheostat to control a dc fan circuit a poor design, but it's also a dangerous one. There exists the potential to set your house aflame. As an electrician and now aspiring electrical engineer, I've seen the results of "handymen" not wiring circuits correctly. If you are dead set on just a rheostat or pot make sure it is rated for what your power supply and load are going to require of it. My suggestion is to check out the LM317 voltage supply circuits (which are really simple and cheap) or braukaiser's 555 PWM circuit.

 

I would just buy a small fan off Amazon like this one or this one. They are cheap, have speed control built-in, and make a decent stir starter. I have made a stirrer using the 2nd fan and just got the first fan delivered to make another starter. IMO all of the articles describing how to wire up the circuit and build it using a cigar box are outdated and not as cheap as described if you factor in having to get a solder iron or using wire nuts. They may be cheap but I hate wire nuts.

 

If you remind me, I'll show you how I made mine. Like Sethsticles said a fan with speed control built in the the easiest way to do it.

 

Corbmoster & sethsticles, I'd love to see your setups and any instructions or tips you might have. I'll likely be building a stir plate soon and would love something that's inexpensive and has been proven on the battlefield. Thanks!

 

http://farm2.static.flickr.com/1280/667225789_8e85017442.jpg

This. Use this. It's a bit more work wiring it up, but it's the proper setup.

 

Agreed. I used the second one you linked to and mounted it in an old tupperwar sandwich container. Worked like a charm and everything to mount it was built in. Magnets from the dollar store work just fine (I double them up) and an old iPod power adapter to attach USB to an outlet.

 

Here you go http://imgur.com/a/tSa7N