Future EUCs

[OliverH]

I had a dream:

• I personally see a tall, compact EUC with pedal arms eliminated, 
• much bigger diameter of the stators
• dual stator possible for redundancy
• Battery/ control board inside the stator ring
• redundant battery, harness, control board
• lights, reflector, brake light and direction turn lights
• Street legal approval 

This dream wasn't sharp enough to see the manufacturer name on the EUC. It looked totally different to current designs.

What do you think future EUCs will look like?

 

[Mono]

I always thought bigger stators and less weight don't go together. So what's the trick here?

What do you mean by pedal arms (eliminated)?

[OliverH]

A design like the Solowheel and the Fastwheel without stator disc and axle/shaft.

So the coming loose pedal arms which are prawn to fail are eliminated. 

Stator rings (double stator or double winding 3-phase/ a 6-phase winding) and not this small motors like on the Eva (maintenance free for the motor itself). The stator rings are screwed to a main ring where guiding roles (maintenance/ sealing could be an issue) are attached to. The guiding roles needs to make sure the air gap of stator/ rotor is set in a min/ max range

Battery is attached in a shock proofed case to the main ring in the middle/ upper area. 

The main PCBs, the motordrivers (seperated design) are attached at the top in a case also. This makes cable harness short, especially the phase wires.

the case is screwed to the main ring

pedals are attached to a holder which is attached to the main ring in the bottom.

The main issue is the sealing. Using guiding roles ther's no sealing of the stator area by default. Maybe replacing the guiding roles with a big bearing could be a solution. Big bearings are normally very expensive but it looks like a German company found a solution to get it cheaper and sealed. But looks like not cheap enough.

With such a design you move weight to other areas or can maybe loose weight also:

• no side covers/ shaft bearing
• no axle/ inner stator disc 
• no pedal arm
• smaller case

replaced by:

• a small holder for the pedals
• the main ring
• Current discussions shows that the redundant stator is not a must have, but redundant control board/ motor driver
• guiding roles (metal/ rubberised plastic)

[Mono]

I am still very skeptical that we wouldn't necessarily gain weight by distributing the motor over a larger space. To my understanding the large motor is the current constructive problem why EUCs are much heavier than they could be if they would have a smaller motor (with the same power) and gearing.

IMHO the foldable pedals are a pretty good choice, because they make the device more compact for trolleying and storage. My V8 has a trolleying width of 17cm and a riding width of 39cm. In order to minimise pedal height and maximise ground clearance, pedals must be thin and sticking out. This makes foldable pedals a very natural choice.

[OliverH]

Making the stator as big as possible gives a better torque.

A normal EUC motor is wasting so much space. It's easier to build, no question.But life needs some challenges. We need a green field approach. Someone starting engineering an EUC, not just assembling with existing parts. From requirement to a solution.

[Mono]

12 minutes ago, OliverH said:

Making the stator as big as possible gives a better torque.

Agreed, to have enough torque we need either a big stator or gearing.