Where do I get gears for stepper motors with double-flat shafts?

I bought 6 of these stepper motors for a robotics competition, but I can’t find any gears that will fit the shaft type. I’ve added an image of the stepper. I also found this thing but I really need to use amazon. I think the shaft is called double-flat.

Image from Original Post so we don’t have to download it. See this Image Guide

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…R

Will it take a gear with a round hole and one or two grub screws?

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Robin2:
Will it take a gear with a round hole and one or two grub screws?

...R

Maybe.... I don't really want to do that unless I absolutely have to. Would a gear with grub screws have enough stability for an autonomous arm? The other problem I can think of is that the shaft might not be long enough for that.

Would a gear with grub screws have enough stability for an autonomous arm?

Yes, especially since that particular stepper motor can't provide much torque.

A bit of a bodge but, if you can find a "double flat" wheel like in your link that is a good fit on the shaft and a gear wheel with a round hole that is a good fit on the shaft, then you could 'marry' the two together such that the double flat wheel acts as a flange on the gear wheel.

Consider epoxy to fill the voids on each side of the shaft. May not bond to the plastic gear, but will bond to a brass motor shaft.

Paul