I got these Pittman motors GM9234S022-R1 from ebay (4 pcs for aprox. 120$) from a shop called raysnow. The gear ratio is 38.3:1 which gives 127 RPM.
My plan is to use standard differential steering with driving wheels from a kickboard which have excellent high friction and good stability with double ball bearings and they are [...]

I had very good experience with omniwheels as Idle wheels in a differential drive robot. I have a 10kg robot with some smaller omniwheels and it just works perfect. Normally these wheels are used for transport systems in the industry, but they are perfect for robots too.

This type of wheel takes no extra space when [...]

he Pittman motors i have is unfortunately not prepared for Encoder mounting.
On the ungeared side of the motor there is only about 2mm shaft free.
My solution to this was turning a small aluminium shaft extender and presfitting it on the small shaft and fastening with some lock-tight. The shaft is now about 12 mm and [...]

Just finished mounting the motors on an angle aluminium. The shaft is 8m an is running trough 2 ball bearings and a cardan joint. I had a lot of trouble getting the shaft straight and in center of the motor shaft, but managed to get all alligned at last. Tomorrow i will put the wheels [...]

I have now connected the driving unit to the body. The body is supported by 4 20lbs gas springs mounted on the driving unit.
I connected the battery and motors together with s switch and took it for a ride down the long hall….Nice fast walking speed and lots of power and traction.
To make stress test [...]