Stir plate fan mount position

I am about to build a stir plate and am curious about mounting the fan. It seems like bolting it to the bottom of the project box would be more stable as the bolts and nuts would not cause the flask to be uneven and I could put some rubber pads on the bottom.

It also seems that if I do mount to the bottom the magnets will be farther away from the stir bar and have less pull.

What do most people do?

Thanks

You want to mount it as high up as you can. You'll be taking all that awesome magnetic force away by mounting the fan on the base plate.

The fan might not be perfectly level but the project box still sits flat on its base. The fan height won't change stability.

I put long bolts through the bottom and then used nuts to adjust the height of my fan as high as possible and it works great.