What should I use for a gear-shaft?

I’m trying to create a small gearbox for a small DC motor using some plastic gears with a 4mm diameter shaft hole. I have been trying to find something to use as a gear shaft for a while now and I am not having any luck. What do you guys use for this purpose?

Hello @martyfay,

Welcome to RobotShop community.

Unfortunately, the closet options we have are 1/8’’ and 6mm.

You can contact the manufacturer directly and order the 4mm one from this link:

Let us know if you need further assistance.

Sincerely,