No more tears in your kitchen as from now on you will be hacking and slicing these annoying onions in seconds!

Custom designed 4:1 involute planetary gearset and easy to grip bowl and ring gear for big torque capacity and blade speeds up to 340 rpm. No escaping these blades for your onions anymore!

This fully 3d-printable onion cutter makes use of the fact that an M3 tap screw fits perfectly through the hole of 9mm stainless steel cutter blades.

compared to it's functionality, it's a rather easy print:

• no support needed
• only small (11mm wide) bridges and some hole bridging
• no overhangs above 45°
• big bottom surface for good bed adhesion
• no tweaking of the parts needed
• small internal surfaces for correct hole bridging have been integrated in the parts
• coordinate systems have been reoriented so parts are placed in correct printing orientation automatically
• tolerances have been considered so parts do not have to be modified after print (except pushing out bridging in some holes), also print quality doesn't need to be perfect.
• small edge chamfers have been added to the bottom side of the gears. Not only is this common in modern gear design, but it also makes up for over-squished first layers so you won't have to clean the teeth.

I managed to print this on my (poorly calibrated) Prism (a mendel derivate) with a damaged nozzle, uneven print bed and leaning problems and it still works like a charm!
I had printer parts coming loose halfway through the print, filament clogging and still it works. So don't be scared by the sheer volume of the parts, you who own a makerbot should really have no problems, this is a very forgiving print.
Total print time was ~10h with the bowl taking up almost half of it. I printed .3 layer height at 30mm/s so one might even be able to print it considerably faster. Total filament used was ~20m of 2.95mm PLA.

The ring gear is glued into the shaft gear using a shaft-in-shaft bearing concept. You have the option to go for an easy version where the ring gear is only held in place by the planetary gears. For more information read the Instructions.

demonstration of blade speed:
https://www.youtube.com/watch?v=5T4PXQD87Pg
proof that it works: =)
https://www.youtube.com/watch?v=kWxKJF94bA0