<p><b>Note: This was not test-printed yet and the SCAD code is still alpha.</b><br></p><p>This design is copied from:<br>"ThinkGeek :: Nanodots GYRO DUO: Magnetically Gyroscopic Balls"<br>http://www.thinkgeek.com/product/18ae/?pfm=homepage_BestDeals_10_18ae<br>and brought into a well FDM printable form.</p><p><br></p><p>Default parameters are for magnets<br>with: h = 5mm - d1=25mm - d2=15mm</p><p>possible source:<br>https://www.magnet-shop.net/neodym-magnete/scheibenmagnete/scheibenmagnet-250-x-50-mm-n50-nickel-haelt-86-kg::250.html<br>https://www.magnet-shop.net/neodym-magnete/scheibenmagnete/scheibenmagnet-150-x-50-mm-n40-nickel-haelt-48-kg::48.html</p><p>86kg & 45kg holding force on full contact ! Take care of your fingers !</p><p><br></p><p>### How to find the optimal magnet(s):</p><p>You may need to recompile the stl files for your specific magnet size.<br>It is assumed that all magnets have the same thickness.<br>Try to choose the two magnet radii such that they fill a common sphere as good as possible. <br>For feedback the OpenSCAD code echoes two "corner radius factors" back. If one of the magnets has a "magnet corner radius" factor below 1 you may want to increase this magnets radius or alternatively decrease the other magnets radius until both factors are near one.</p><p><br></p><p>### Tipps for making the gyro-ball:</p><p>*) Thinner & harder bearing pins should significantly reduce the probability of mechanism clogging since the magnets then create higher lever forces.<br></p><p>one could use pieces of:<br>iron nails / copper wire / brass rod / printing filament / toothpicks? / ...</p><p>*) Tip for making pins from filament:<br>Use a retractable utility knive to make a notch into a piece of ~3mm diameter PLA filament then use pliers to break the piece of (ABS may not be brittle enough to break) then cut eventually occuring pieces that deviate from a flat fracture off.</p><p>*) use thinn oil to lubricate the joints<br></p><p>*) keep mass of the gyro parts small (low infill) but note that this is not that importatnt since the magets are heavy anyway.</p><p><br></p><p>### Further notes:<br></p><p>*) through all the mechanics it's unavoidasble that the distance between the magnets becomes quite significant => big magnets that create big balls with relatively thinn shells are preferrable.<br></p><p>*) when it comes to gimbals you should know about the gimbal lock<br>http://en.wikipedia.org/wiki/Gimbal_lock</p><p>*) the OpenSCAD design is animatable!<br></p><p>*) it might be interesting to try adding excess mass to one magnet side<br></p><p>*) are there sources for fully transparent plastic balls?<br></p><p><br></p><p> </p><p>### Infos about some of the design decision:</p><p>*) All sizes are dynamically generated from magnet size so that the maximum amount of magnet power can penetrate through the shell</p><p>*) For simplicity of design and assembly an irreversible assembly design was choosen that includes glueing and or plastic welding.</p><p>*) the gap between the gimal ring and the gimbal sphere is determined indirectly via the "bearflatadd"-patrameter (no specific reason for that) <<< change?</p><p>*) in the code:<br>radii with underline postfix correspond to the radii of the bearing flats<br>radii without underline postfix correspond to the majority of the gimbal surfaces</p><p>*) the parameter relationships became so complex because all the stuff has to be cramped together to the absolute minimal space</p><p>
</p><p>*) GPL was choosen as license because lack of original idea but quite a lot of code</p>
GPLv3
