Wheelchair pusher robot

A compact and simple wheelchair pushing device. It almost feels like the invisible man is pushing you forward. I have more then one additional device I can connect to my wheelchair and all of them are useful but what I was missing the most was something compact that can go into the car and can be an additional assistant when you go on a walk with your wife but the road is uphill or uneven.

See here on YouTube https://youtu.be/l2qZZt24OhY

It also should be hidden so going into a restaurant doesn't make your wheelchair much larger. I have one of these bikes you put in the front but these you need to leave outside and they are bulky to travel with.

This device is just great and not that hard to build. I have a Panthera U3 wheelchair and for every wheelchair you might need to design it a little different. So 3D printing in this case is just the right way to do this.

What I bought to make this work.
1. You need an electric wheel. I bought a spare wheel (E_Scooter 3000/3100 F la