Why not a gas engine instead?

[BA-B8]

Sorry I'm not too technical but why isn't there just a gas engine powered one?  Seems like most of the complaints about EUC's on here are either about power, range, or cut offs (safety). Basically folks dream of a single wheeled motorycycle pretty much right?  Does it have to be electric to have be self balancing, but I think there are some gear driven ones like the old Rockwheels right?  So why can't someone just build a gas powered gear driven monster unicycle with tons of HP and will never cut off?

[noisycarlos]

I think the main challenge (even if you find room to put an engine and a gas tank) is latency, or the delay between the input (the angle of the pedals) and the output (the adjustments the motor makes to keep you balanced).

In other words, I don't think a gas engine can respond quick enough to keep the rider balanced. 

Plus the gas engine needs to be revved up for max torque, so you might need a transmission, which adds latency and complexity.

All that's without considering how to reverse direction of the force (when you lean back on the unicycle). 

If you could figure all the technical issues, it wouldn't be a simple machine as it is now. But there's other practical things that wouldn't make it appealing like noise, fumes, dealing with gas, etc. I definitely wouldn't be able to bring it grocery shopping.

 

[Frode]

Oh, they have been here longer than the EUC:

 

One wheeld motorcycles have some potential risks though, especially when you put a V8 in there:

 

[LanghamP]

In the early 20th century combustion-electric cars were extremely popular whereby the gas engine filled up a battery or a capacitor and then that battery drove the wheels. My understanding was gearboxes were prone to breaking, and hence electric drives were simpler and less prone to breakage but at the cost of effeciency.

To me a big appeal of monowheels is the lack of moving parts. I'm sure my v5f has a number of moving parts, but to me we have the wheel bearing, the two footpads, the two panels to get to the tire, disarm trigger and the two parts of the dolly.

That's eight moving parts. Arguably you just need the wheel bearing.

Perhaps a roll-out solar panel would work better for recharging a monowheels.

[meepmeepmayer]

We had a thread recently with the same question, but a portable generator instead of built-in engine. The same arguments apply.

A gas engine would really loud, vibrating, and is heavy and needs a lot of extra space. In the end, it goes against the simplicity of EUCs. Electric motors are a pretty neat thing if you think about it.

Not that I would mind a nuclear or hydrogen-powered EUC with 1 million km range (well maybe not nuclear)

[Hunka Hunka Burning Love]

If you think about it, when a motorcyclist pops a wheelie and rides around on one wheel, he/she is basically doing what we're doing but controlling the balance through throttle input and braking.  Now if someone were to incorporate a self-balancing control board that controlled the throttle and braking I think it would be theoretically possible to balance with a gas motor.   It might need a CVT though.  I could see someone adapting a lawn mower or go-kart engine into a set up like this:

Or someone could adapt a pop-a-wheelie cruise control board onto a regular motorcycle and engage it to ride around on one wheel...

[Gimlet]

You show me a way to gear an internal combustion engine so that it can instantaneously switch from forward torque to rearward torque from zero miles an hour.

Once you conquer that small hurdle the electronic control of the process for it to self balance is fairly simple, relatively speaking anyway!

[esaj]

9 minutes ago, Gimlet said:

You show me a way to gear an internal combustion engine so that it can instantaneously switch from forward torque to rearward torque from zero miles an hour.

Once you conquer that small hurdle the electronic control of the process for it to self balance is fairly simple, relatively speaking anyway!

Just off the top of my head, some sort of clutch-mechanism with discs spinning in opposite directions (forward/backward) all the time could maybe work, but they would probably wear out pretty fast and the smell of burning metal would be pretty intolerable (if you've know what a burning clutch smells like...)

[Gimlet]

9 hours ago, esaj said:

Just off the top of my head, some sort of clutch-mechanism with discs spinning in opposite directions (forward/backward) all the time could maybe work, but they would probably wear out pretty fast and the smell of burning metal would be pretty intolerable (if you've know what a burning clutch smells like...)

Sounds like a very bulky, heavy weight solution to me esaj!

[lizardmech]

You could do it with hydraulics. A small IC engine as a range booster would probably work better. You could probably get 500km range out of a hybrid version of the larger wheels.

[Cerbera]

On 09/03/2017 at 1:22 AM, BA-B8 said:

Sorry I'm not too technical but why isn't there just a gas engine powered one?  Seems like most of the complaints about EUC's on here are either about power, range, or cut offs (safety). Basically folks dream of a single wheeled motorycycle pretty much right?  Does it have to be electric to have be self balancing, but I think there are some gear driven ones like the old Rockwheels right?  So why can't someone just build a gas powered gear driven monster unicycle with tons of HP and will never cut off?

If our wheels were gas powered we would have no eco-advantage over all the other filthy noisy traffic on the road. And with that goes our only argument that these are the future..

[Hunka Hunka Burning Love]

18 hours ago, Gimlet said:

You show me a way to gear an internal combustion engine so that it can instantaneously switch from forward torque to rearward torque from zero miles an hour.

Once you conquer that small hurdle the electronic control of the process for it to self balance is fairly simple, relatively speaking anyway!

Where there's a will there's a way!  I've learned over the years that there is always someone very ingenious out there who can figure out how to make things work.  I'm sure if you gave this problem to a bunch of mechanical and electrical engineering students at an university they'd probably surprise you.  I would never have imagined someone would be able to invent a solar plane that could fly around the world without landing, but they did that...  Plus those crazy pogo stick robots hopping around....  I don't have an engineering background so maybe it is impossible, but I've been surprised before by stuff so I wouldn't be too quick to say that it's impossible.

Maybe a electric motor to handle the reverse balance direction would work.  The forward movements would be handled by the gas engine giving more range.

[JimB]

Well, I think many of us use EUCs because of the low noise and zero-emissions.  (OK, "extremely-low-emissions" if you want to raise the argument of deferring emissions to the power plant.)

But that aside, there would be some significant technical challenges.

1. Electric motors have max torque at zero RPM.  Gas engines can't function at zero RPM.

2. When idling, a gas engine has very low torque.  To be useful, a gas engine needs to be pushed above idle so that it can do work.

3. There is a lag while a gas engine increases RPM above idle to the point where work is possible.

So, we need a running gas engine.  We need to run above idle because we can't incur the lag while increasing RPM.  (or we face plant)

Next we need a clutch mechanism of some type, because while our engine is running at some RPM, our wheel may be standing still.

The clutch mechanism would need to be extremely precise in adjustment of torque to quickly and precisely achieve the desired rotational speed of the wheel under different amounts of resistance.

This isn't my area of engineering, but I think it would be extremely difficult/expensive to achieve this.

These are all areas where an electric stepper motor excels.  So, while we could pound in a nail with a screwdriver, a hammer is simply a superior solution.

 

Now, what you COULD do, is build a hybrid EUC.

Use a conventional EUC, and mount a small gas engine on it.  The gas engine would run at a constant RPM, driving a small electric generator which would power the batteries driving the electric motor.  With a backpack full of gas, this could allow you to travel 100s of miles on your EUC.  Of course, who wants to travel 100s of miles on an EUC (carrying a backpack full of gas)???  Anyone up for a challenge?

[Hunka Hunka Burning Love]

@Marty Backe comes to mind.    I'm all for electric, and of course it just makes more sense in all respects.  I was just commenting on the possibilities of creating a gas powered EUC as a theoretical exercise.  My thinking is that if a motorcyclist can zoom around balancing on one wheel at moderate speeds, it should be possible to make a computer take over the balancing control and have the rider just balance side to side just like on an EUC.  If riding backwards is crossed off the list, that would make things less complicated.  

[steve454]

4 hours ago, JimB said:

Use a conventional EUC, and mount a small gas engine on it.  The gas engine would run at a constant RPM, driving a small electric generator which would power the batteries driving the electric motor. 

That is hidden technology sir  The government won't allow it at this time.  I had the same idea thirty years ago to power an automobile.  In Popular Mechanics magazine, a long time ago, there were kits advertised that you could put a 2.5  horsepower motor in your car and power an electric generator to power an electric motor to make the car move.   But they never caught on for some reason.

However, modern trains use diesel electric propulsion, but the diesel engine varies in speed according to load.  And AFAIK they don't have batteries, the diesel engine drives the generator to drive the electric motors.  Maybe the rapidity of speed change prohibits this in something as small as an EUC.

Two more ideas I had long ago, the dual flush toilet, light flush for no1 full flush for no2.  Seen it but it didn't catch on, low flush toilets that can do both are becoming the norm.  I wished that my car radio could record any song just played that I liked, Duh, now you can replay any song you like on your phone.

 

 

[JimB]

3 hours ago, steve454 said:

However, modern trains use diesel electric propulsion, but the diesel engine varies in speed according to load.  And AFAIK they don't have batteries, the diesel engine drives the generator to drive the electric motors.  Maybe the rapidity of speed change prohibits this in something as small as an EUC.

I think for a GEUC (Gas Electric UniCycle), just like a Prius, the engine would only run once the batteries dropped below a certain threshold.  So you wouldn't need to vary to engine speed, just run it periodically, and then shut it off.  (I'm pretty sure the Prius has some fancy hybrid drive for highway driving, but will omit that for simplicity.)

[MetricUSA]

Extremely Loud Noise and fumes....

[Ombre]

This is a brilliant idea.  In fact, I've been working on this concept for a while so I was excited to see others grasp the value of powering our wheels with fossil fuel.  But after studying diesel-electric locomotives, I decided that a gas engine would not provide enough torque.

So, I bring to you the world's first DIESEL AIRWHEEL based on a 1984 Mercedes W123.

As soon as I can get EPA approval in the US you can expect to see this for sale.  (European approval may take longer.)

• Top speed:  4 MPH (6.4 kph)
• Carbon output:  250 grams/km
• Torque: 162 N-m at top speed
• Fuel capacity: 1 liter (worn in hat, see photo)
• Range:  120 miles

The photo doesn't show the mandatory 2 foot tailpipe, which is detachable for storage purposes.  Still working on a sufficiently compact muffler design.

If you would like to get in early on this business opportunity please see my Kickstarter page and donate any amount from $50,000 (Early Bird) to  $100,000 (Super Donor).  Cash only please.

[Hunka Hunka Burning Love]

Sorry to bring this thread back from the dead, but as an interesting mind exercise, I wonder if EUC's could ever get to the point where they could climb up obstacles like this guy does.  I know he's hopping around quite a bit to help stay balanced and climb over the rocks, but if electronics took over the balancing part and if they put a large knobby tire on an EUC I wonder if someone could do the same thing with an electric one day...  We already have these with the handlbars up front. 

Maybe the handles and throttle / brake on the gas version help with climbing stability rather than relying on body lean applied pressure to foot pedals.  It's probably way hard to lean and keep balanced on an electric while climbing such tough terrain.  Maybe if the gyro input was control by the throttle instead of the pedal/control board axis... (eg. put the gyro sensor in handle control) it might work?  That would defeat the self-balancing part though...

 

[dmethvin]

On 3/8/2018 at 10:00 PM, Hunka Hunka Burning Love said:

Sorry to bring this thread back from the dead, but as an interesting mind exercise, I wonder if EUC's could ever get to the point where they could climb up obstacles like this guy does.  I know he's hopping around quite a bit to help stay balanced and climb over the rocks, but if electronics took over the balancing part and if they put a large knobby tire on an EUC I wonder if someone could do the same thing with an electric one day...  We already have these with the handlbars up front. 

 

It seems like it should be possible. Maybe the electronics would be less aggressive in balancing and you could use your body within some range to provide more flexibility in climbing.