Magnetic stir bar (parametric)

Has your colleague / student / past-self lost the last stir bar down the drain (again) ?

No problem, because you have a 3D printer.

And because you have a 3D printer, you also have magnets!

(Don't ask me why. It's just a law of nature, I guess)

Now that you feel called out, don't worry, for I also have magnets.

And if you choose a split version, you will also need superglue or equivalent.

To save you time and/or annoyance, I have provided here a solution.

A PRINTABLES solution. 

(If that all caps platform plug does not get me the throphy, I dont know what I did with my day :)

The first magnetic stir bar on printables!

This is a parametric template for fusion 360; just download it, open it in fusion and change the variables to your personal likings (size and amount of magnets you may have lying around waiting to be used)…

Available variables:

• Diameter of stir bar
• Length of stir bar
• Diameter of magnet
• Height of magnet
• Number of magnets

Yes, you can break the model if you choose magnets that are larger than the stir bar itself, so please just don't.

There are currently 2 versions: 

whole stir bar and split stir bar 
(because some of us have not so perferct printers and like lots of post processing)

Now, I know not everybody is comfortable with fusion 360, so I have provided a few common stir bar sizes in combination with various magnet sizes.
If you want more options, just drop me a comment. 

Please choose a filament according to the final use of your stir bar, i.e., dont drop an ABS stir bar in acetone, dont heat your PLA stir bar above 60 °C (140 F / 333,15 K) etc.

A few tips regarding magnet choices:

• The stronger the better
• The longer or more stacked magnets the better
  (¼ of the stir bar length seems to work alright)

Printing:

Orientation: whatever your printer and nerves can handle

Infill: 100% (nobody likes a floaty stir bar)

Adding magnets: pause at suitable height or add after finish for the split version.

Q and A:

Why didn't you make a better job with this file?

• Because i'm an amateur and this is my first puplished file. Thank your for your feedback.

Why is the stir bar flat on 2 sides?

• So it can lie flat and not roll from the table and we don't have to print another (again).

I can't find a suitable filament for my application, what should i do?

• You could try to coat the stir bar in something inert (maybe silicone?) Not an expert.

You have a question that is not answered here?

Please leave a comment :-)

History: 

12.5.24 Version 1.0: Release-Version

12.5.24 Version 1.1: Fixed missing constraint