I was looking for a stir plate to keep a Yeast starter agitated but they are very expensive for what they are and i have access to a 3D printer through school so i though i would make one myself to work with an old 3.5 inch computer fan i had lying around. this is made to use these magnet and a 1 inch stir bar like this

Step 1: Magnet Holder

this part is particularly important as it is glued to the center of the fan and transfers energy from the fan to the stir bar.

Step 2: Top

the magnets are meant to spin in the middle as the rest supports the container

Step 3: Body

houses both the fan as well as the power supply (i use a 9V battery but there is a cutout if you wish to use an outside power source) and a potentiometer can mount through the side for power ans speed control.

the bottom is built to house four M6 nuts that along with the 75mm screws will hold the box together

Step 4: Speed Control Knob

this knob should interface with most variable potentiometers if you do not have your own.

Step 5: Files

my original part files as well as printable .stl files . there are also PDFs for the screw ans nuts i used for my assembly

i have not printed out one for myself yet, I apologies and will add assembly photos/ instructions once i do. for anyone who risks going on before me i would love your input