My Thermaltake DIY Cigar Box Stir Plate

[geoffm33]

Like a few others have, I built my stir plate using the Thermaltake USB fan as it has most of the components we need to run a stir plate (power, fan, potentiometer).

PARTS LIST:

• Thermaltake USB Cooling Fan 120mm ($20 shipped)
• Wooden Cigar Box (free)
• #8-32 bolts, nuts, washers (~ $5 at Home Depot)
• iPhone wall wart (free)
• 2 rare earth magnets from a busted hard drive (free)
• Fender Washer (under $1 at Home depot)

Total cost: $26

I am also using a cigar box as the enclosure, it used to be a wall clock (see the hole in the cover where the clock mechanism once was):

I drilled holes through fan corner-holes and through the bottom of the cigar box and secured #8-32 bolts, washers, nuts to form the mount for the fan:

I mounted the fan and secured it with washers/nuts:

I drilled through the front-right of the cigar box to give access to the potentiometer mounted inside. I also drilled through the back right for the power cable:

Here is the mounted potentiometer:

I attached the fender washer to the fan with velcro strips, but I need to make it more secure, works for now. The hard drive magnets stick right to the washer, be sure to center it so it doesn't throw the stir bar.

Here is the finished product:

 

[breckenridge]

Looks great! How big a starter can it stir? I bought a stir plate that'll do 2L, but thinking to DIY one that will do up to 5L starters, wondering if this fan/magnet combo can produce enough pull.

 

[geoffm33]

I tested with 1.5L of water and it was fine. The fan is pretty powerful but not sure how big it can go.