ideas on balancing a stir plate?

[BigFloppy]

So, I'm very used to my DIY stir plate having a semi serious wobble when spinning... I just picked up a commercially available stir plate... ZERO WOBBLE



How do we go about balancing our DIY stir plates?

 

[imasickboy]

Glue a washer to the fan. You can easily spin the fan and see if the washer is not centered. Stick two round magnets on the washer, adjust as needed until they're spaced correctly. No wobble.

 

[day_trippr]

Honestly, it's more art than science, though it helps to use symmetrically shaped components (which pretty much rules out hard drive magnets).

I started with a large fender washer and used a casting dimple in the dead center of the fan hub as a visual guide for initially centering the washer atop the hub. Then I slowly rotated the fan with one hand with a fingertip on the other hand barely touching the edge of the washer, which gently nudged the washer to the center. A puddle of crazy glue dropped in the center of the washer fixed that in place.

And using bar magnets made centering them on the washer pretty easy. They're naturally aligned, so it was just a matter of getting their meeting point centered through trials and adjustments before they were cemented down. Button magnets wouldn't have been as easy...

Cheers!

 

[bmaupin]

I used a washer as well. I think it is the key.