Canadian Spinner

Here's a youtube video showing the spinner in action.

This spinner design uses 10 embedded 3x2mm magnets (these from Amazon) to force alignment between the spinner body and the bearing caps (handles). Weight is provided by 10mm ball bearings. You only need 5, I ordered a couple hundred because I make a lot of spinners. I use this R188 center bearing. I wash these bearing in ISO alcohol to remove as much grease and lubricant as possible. You don't want any, as it slows down the spin.

You can try the attached STL file. But this model is very sensitive to sizing to ensure all the magnets, bearing and weight fit properly and tightly. The original f3d file is also provided in case you need to tweak things a bit.

The magnets amplify the “fidget” nature of these spinners. No one expects the magnets when they pick it up, but everyone likes them.  These are not designed for really long free spins. They are truly designed for fidgeting (especially during Zoom meetings). The magnets make you want to fidget with them all the time.

(One note about this bearing and the magnetic nature of the spinner is that when held with one side up it spins smooth and quietly.  When held with the other side up, there is a distinctive clicking sound and it does not spin as smoothly. I think it is some asymmetric property of the bearing interacting with the magnetic pull against gravity. Not really sure. I simply consider it a feature that just adds to the fidgety nature of this thing. Someday I might try different bearings (when I run out of these) to see if this behavior changes.

They are fascinating to play with and explore the behavior. The harder you hold it, the longer and smoother it spins. Loosen you hold on it just a bit and they will slow down and stop very quickly. Put it on a desktop and hold it down hard with your finger and it will spin for a long time (longer than you will want to hold it), but let up just a bit and see what happens. Or just let go.

It may take a few experimental prints to make sure your print fit the steel balls bearing weights, magnets, and center bearing. they are all press fit, but can be glued using CA if needed. Though I don't recommend gluing the weight if they are loose, you want them pretty tight. 

The bearing caps are press fit together…permanently. You won't be able to take them apart after assembling without breaking them (so print some extras in case you mess up the assembly :) 

When inserting the magnets into the caps and body, you need to make sure they are all N/S aligned. You want the cap to want to “attach" to the body (i.e. no facing magnets should repel each other). It can be a tricky process with these tiny magnets. They must all be pressed/glued into their slots with the same N/S alignment. It might take a few tries to get it all correct (at least it did for me…)

My preferred method is to insert the magnets into the body first. Press fit the first magnet (use use a small steel bar to press the magnet into the hole. Alignment is not important for this magnet as it simply sets the alignment that all other magnets need to match. I use the edge of dial caliper bar, which may not be the smartest use of a precision instrument! If it presses in tight, then it won't come out with the steel bar. If it comes out, use some CA glue to make it stay. After the first magnet is in, place the second magnet onto the first (this will ensure they are properly aligned in polarity) then place the steel press bar on the magnet and slide it to the next hole and press it in. Do this process for all the magnets in the body. Now move on to the bearing cap handle. Start by placing a magnet onto one of the body magnets, then align and press the handle down onto the magnet so it presses into the handle. Then repeat for each handle magnet. Once all the magnets are inserted, attach the handle piece with the magnets to the body to double-check that all the magnets are attracting and not repelling.

After the magnets are all correctly inserted, press the center bearing into the body (you want a tight fit here so the bearing doesn't move). Then press the handle piece with the axle through the bearing (again a tight fit ensure smooth spinning). Then press the magnetic handle piece onto the handle axle.

Also, you can simply omit the magnets if you want a free spinning spinner. Or make some of each!

A f3d file is attached. If you are proficient in Fusion 360 (or if you want to learn). You can edit this model, replacing the Canadian Maple Leaf with some other logo, or adopt to different size magnets, bearings, or weights. 

My original design for this spinner was using a corporate logo for the company I work for (which fit a pentagon perfectly, and why this is a pentagon and not some other polygon).

When you slice it, you'll need to insert filament changes at the correct layer boundaries in order to get the multi colored effect.

You need to print the handle pieces separately from the body since the filament changes happen at different layers.