LEGO Wheel Adapter


Your LEGO Wheel Adapter for 3mm Hexagonal Shaft is a great idea, but for LEGO users (like myself) this idea could be improved.

If you make the round part of your wheel Adapter, exactly, 3/16" (LEGO hole) and the hole of the adapter a D-shaped hole, so that, it fits the output shaft of the micro metal gear motors you carry, then, it is possible to fully integrate, easily, the great micro metal gear motors to the LEGO system. I had done many tests on this.

The LEGO system is one of the more powerful system for mechanical prototyping of robots that I know, but one of its weak points is its lack of variety of motors.

If you make an adapter with the suggested modifications, LEGO users will worship Pololu forever !!!



Thanks for your suggestion; we’ll look into that. I’m not sure I understand the 3/16" part. Are you thinking that you want the adapter to be small enough for the whole thing to fit through the LEGO hole? I don’t think that would be possible since the 3mm motor shaft would leave us with really thin walls in the adapter that would probably make it too fragile.

- Jan


Yes, that is exactly what a mean, that the adapter to be small enough for the whole thing to fit through the LEGO hole. The reason to this is that once the shaft of the motor is in the center of a LEGO hole, automatically it fits all LEGO geometric properties which makes it compatible with the whole LEGO system.

In relation to the fragility of the shaft, I am not really sure, what I can say is that it is a common practice to adapt 1/8" round output shaft motors to the LEGO systems, using the Axle Pin Without Friction Ridges (LEGO part no. 3746) . This axle pin has a very thin walls, actually, it has to be that way, because the pin has to bend in order to be able to go through the hole. I am not really sure of the mechanical part (I´m an electronics guy) but I suppose that the axle fits, so well, into the hole, that the walls of the LEGO hole itself, support the hole thing together.
But, you could be right, some tests have to be done.

Another approaches could be:

To make motors with 1/8" round output shaft…I think, this is harder.
To make a special mounting frame to the body of the motor which makes it fits the LEGO geometric properties, together with an axle adapter.