I would like to build a magnetic stirrer hot plate. I do not want to use a 12v pc fan, the web is full of such designs and unless your stirring hot water it does NOT work well. I plan on building one use a pwm from amazon(RioRand Upgraded Adjustable DC motor speed PWM controller,10-12-24-30v 120w with reversing switch. $10.99)Probably more then I need, but gives me more options motor wise. Then I was planning on using a 12v 1500 rpm motor, that should run at 1500 rpm at 12v and max watts, allowing me to slow it down to about 150rpm's =/-.(12vDC1500RPM high torque motor by amico $13.14) I already have plenty of rare earth magnets and am sure I can fabricate the other parts. The issue is that I would also like it to be a heated magnetic stirrer and am not sure how to accomplish this. I have heard I could accomplish this with a ceramic electric thermo cooler along with a DC controller to adjust the power to the TC. It had also occured to me that I could possibly take a hot plate and modify it to be a stirrer as well. But to do that it would require a hot plate and knowledge of it. For the record I am ordering the parts from amazon.com because of a few gift cards that I need to use. Any suggestions would be appreciated, even more so if you can provide the part #'s from amazon! I have access to a large collection of dc wall plugs in all type's of amperage, I am waiting to get that last to make sure it has enough power for the whole thing. Although I have a few gift cards, ultimately I would like to be able to get it done for under $40-$50 total. Thanks for your time and all advice. Bradford

 

Do you have any reference or link to an example of what is involved?
Max.

 

Pie in the sky thought: A disc large enough to fit over heater with wheels running on single rail track with magnet on top surface which makes close non contact with flask. Stiring element = steel ball. Rim or belt drive of disc??

 

I would like to build a magnetic stirrer hot plate.

What's wrong with the many commercial choices?