Buying the wrong magnets for a stir plate

[Tōtōchtin]

I am building some stir plates to help keep my yeast costs down. I bought some magnets from AliExpress . First were some NdFeb 12mm x 5mm these were to weak. So I ordered some n52 18mm x 8mm, I knew I was in trouble when they were difficult to separate. These interfered with the 12 cm fans motor. Now I plan on cutting these in two,before placing another order.
Tōtō

[quadra]

Is your stir plate homebuilt from a computer fan? Those diy plans always downplay the fact that those motors typically are not designed for speed control. Did you use piece of Hdd magnet on the fan motor?
Neodymium magnets are way too strong, you are going to end up with broken glassware.
Have a look on Ali for an assortment stir bar set ( $4-8 ) the bars with the center ridge might help and the assorted sizes might allow a better match to your stirrer.... but for not a lot more you can buy a basic stir plate with speed control and many sell with a bar included. A set of bars is always handy and a stir bar recovery wand is surprisingly useful to own.

[Tōtōchtin]

I first bought cross shaped stir bars that just vibrated in the flask. I now have 2" long stir bars. The magnets I bought for my 12cm computer fans were too weak and way too strong. Need the Goldilocks cure.
The stronger magnet can drag out the stir bar without touching the flask.
Tōtō

[Demy]

How I built my version

[Tōtōchtin]

How I built my version

What is the largest amount of liquid that you have tried with a one inch stir bar? I want to use 2 liter flasks so I am planning on using a 2 inch stir bar. Heat I will not need in the tropics , but that was a good idea.
Tōtō

[Demy]

How I built my version

What is the largest amount of liquid that you have tried with a one inch stir bar? I want to use 2 liter flasks so I am planning on using a 2 inch stir bar. Heat I will not need in the tropics , but that was a good idea.
Tōtō

I'll do a quick test and let you know the result

[Demy]

The container is less than two liters... but it can give a good approximation.

My treble hook measures approximately 2 cm

[Tōtōchtin]

I thank you for taking the time to do that for me.
Tōtō
10 lifetimes ago I left Napoli for the US at 13.

[Demy]

I thank you for taking the time to do that for me.
Tōtō
10 lifetimes ago I left Napoli for the US at 13.

Always available for friends of the forum

[Tōtōchtin]

Cutting the magnets in two taught me about the Curie temperature. The crap you learn in this hobby never ceases.
Tōtō