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Uniwheel first impressions


Gimlet

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I had a great day at the Gadget Show in the NEC Birmingham yesterday where I met Steve Milton (no relation) and his team from Uniwheel.

They were kind enough to bring two of the wheels outside to the car parks where my son's and I were able to give them a little bit more of a test than would have been possible in the confines of the hall. 

The ride felt very solid and the software gave a quick reacting but comfortable ride, I believe the ride characteristics are adjustable via the app the the one I rode felt similar to Madden Mode on my Gotways. The slim lightweight case was very comfortable on my inner shins and the pedals seemed plenty large enough whilst not having any excess protruding from beneath our feet, they also have a slight upward incline so should give good ground clearance on the turns.

There are some really good convenience features such as direction sensing lighting and power buttons either end of the top handle so it really doesn't matter which way around you ride it. Then there's the sensors by each pedal that stop the wheel if neither can sense your leg so it not only stops very quickly if you step off but you don't need to power down the wheel to carry it up steps etc.

The power seemed very capable under fast acceleration and idling in one spot, unfortunately there are no hills in the car park so the endurance tests will have to wait until I can get one back to my home city of Bath.

Talking to the team later I was very impressed with the amount of detail and thought they'd put into the design right from the basics of the splined axle rather than the more usual cotar clamping washer arrangement to the idea of moving the control board into the center of the hub which not only protects it from water but also simplifies the access to the wheel and tyre for puncture repairs. They've also saved significant weight by combining the hubs with the rims. I was assured that the quality of all the electrical components used is vastly superior to those normally found in other eucs and that failures are therefore much less likely.

Uniwheel cutaway.jpeg

Looking at the display wheel with clear casings and a cutaway hub you can also see that there are a lot more poles on the stator than you normally find in eucs and if you zoom in and look at the center of the cutaway hub you can just see the control board.

The easily removable batteries complete with a plastc safety blanking block should make it as airline compliant and friendly as any wheel can be, they also add the possibility of carrying a spare to get you home should you enjoy your ride so much that you go beyond the range of the wheel.

Well there it is so far. Everyone was asking why nobody made a really good quality well thought out wheel and lots said they'd be willing to pay a little extra if someone did. From what I see Uniwheel have done a fairly good job of fulfilling that request although software developments are still being made. I'm told any further software upgrades will be avaible via the app to apply by the user.

I was sufficiently impressed to put down my £200 deposit and left the show a little poorer yet in excited anticipation of getting my wheel so I can really torture it on my local hills. Once that happens I'll report further.

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A few more watt hours and they will be sorted.

I would rather have more oomph from the battery than the ability to fly.

Could you put in your own lion batteries or are they completely proprietary.

Overshadows the tesla 3  launch by all accounts.

 

Jer

 

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The batteries are lower voltage, around 50v rather than the more common 60v I believe, similar to the Solowheel and being a different format I would imagine the proprietary packs would be the way to go.Eucs in froot.jpg

Here are the two wheels we got to play with in the car park. Just tested to be sure they would fit in the frunk/froot of my model S.

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I didn't realise you were going on Sunday. I went the day before but looked for you all day. Everytime I went near the stand it was too busy for me to get near & I had already forked out £250 for nail varnish & £40 for hand & back warmers so I didn't wait around to bother them with questions. It was encouraging to see how busy they were though.

I was wondering about the size of the pedals though as they looked small & was worried that the panel would come off in the event of a crash.

Does the automatic cutoff feature mean you can't ride one legged?

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One leg is fine, it only stops the motor when there's no leg either side.

The pedals on the one I rode were fine, a bit bigger than the mcmv2s ones but not so big as to stick out and catch the ground in the turns.

That must be some pretty hefty nail varnish, or are you buying it in bulk? :)

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4 hours ago, Shady Tools said:

Does the automatic cutoff feature mean you can't ride one legged?

If you think about it, the wheel has to power up as soon as you have one foot on it or you couldn't step on to it with the other foot. See 5:27 into this video for a (rather painful!) demonstration of one legged Uniwheel riding:

"I had already forked out £250 for nail varnish". You do know painting an elephant's toenails red so it can hide in a cherry tree is just a joke don't you?

 

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I'm certainly going to root for any company that aims for higher quality/safe experience, for sure. I'd like to try one!

I have to say the leg sensor feature worries me quite a bit though. Introducing more sensors linked to shutting down the motor is introducing another potential point of failure that would cause a faceplant. We already have the 45 degree cutoff for protection against runaway wheels. Obviously leg sensors takes this further by shutting it down if the wheel stays upright as it leaves your control. But that's a pretty rare situation. However, it does seem like this company has put a lot of time and research into their product- maybe more than the Chinese competition. I guess we will see how it behaves when/if lots of customers get their hands on them. 

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2 minutes ago, Jeffrey Scott Will said:

Obviously leg sensors takes this further by shutting it down if the wheel stays upright as it leaves your control. But that's a pretty rare situation.

Whilst it obviously would cut the power in that situation, it also cuts power as soon as you step off of it so you can pick it up immediately, without powering the wheel down, to go up steps, etc. Afterwards, just put it down and step back on. That is a fairly common situation.

I would agree that something like an engine fire in an aircraft or undercarriage not locked down is just as likely to be a faulty sensor as a real fire or stuck U/C and one would hope they are top quality components. However I am fairly confident the designers will have made every effort to minimise this and, unless you are riding one legged, both sensors would have to fail for it cause a problem.

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Hi guys thank you for your interest in our safety features - just two things that inwant to clarify;

 there are couple of soft and hard interlocks that prevent cutoff in a situation that might result in causing injury to a rider. As a result you have to make sure the Uniwheel is not moving when you step off to active this feature, it's fairly intuitive. Those interlocks [limp home mode] also look after your safety when any problem is detected with the hardware and the device in case of faults should provide soft stop by tilting the pedals gradually up till riding is no longer possible and only cuts out when it stops. Saying this we still hope users will remain within the laws of physic - it's 1500W motor it's not invincible it only allows for higher safety margins! So please do ride with care...

Secondly, you can opt out of user presence sensing through our app; kind of like you can disable ESP on a car. Down side of turing it off; you will loose the convince features when trying to walk up stairs or lifting the unicycle up in the air.

Thank you

The Uniwheel Team

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Now that's how you explain features to potential customers- thank you, @Eryk88! That pretty much removes my initial concern regarding the leg sensors, I didn't realize it would only shut down if the wheel wasn't moving.

I know in the past your team has already acknowledged that the battery is on the small side, which I understand is somewhat of a feature for air travel, but there are also other benefits in having more cells to provide the power needed for greater performance and safety especially at higher speeds and inclines. My daily ride involves large steep hills, which destroys battery life. It was implied that this was only the first design and upcoming versions would allow for greater range, power, and speed - can you elaborate anymore on that? 

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I must say I am very excited about this wheel. I very much look forward to its release and availability in the United States.

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9 hours ago, Jeffrey Scott Will said:

Now that's how you explain features to potential customers- thank you, @Eryk88! That pretty much removes my initial concern regarding the leg sensors, I didn't realize it would only shut down if the wheel wasn't moving.

I know in the past your team has already acknowledged that the battery is on the small side, which I understand is somewhat of a feature for air travel, but there are also other benefits in having more cells to provide the power needed for greater performance and safety especially at higher speeds and inclines. My daily ride involves large steep hills, which destroys battery life. It was implied that this was only the first design and upcoming versions would allow for greater range, power, and speed - can you elaborate anymore on that? 

Hi regarding the battery pack's please do not confuse power and speed terms with range...

Power 

Our battery pack is made of A123 cells in 16s1p even though it has small capacity it outperforms let's say 380Wh batter pack made in a 16s2p configuration with let's say Samsung (inr18650-30q). In THEORY our pack can deliver 132Wh (52V x 70A) 3600W continuous power while 380Wh Samsung pack will deliver (57Vx30A) 1800W of power - not to upset anyone this is just for simple demonstration of continuous power delivery of cells disregarding the discharge curves etc...

Speed 

assuming a bigger battery pack would give you 5V increase in voltage just short of 10% it would mean that for our existing hardware you would get in theory 2.2kmh increase in top speed - as we are not planing to change our KV motor constant.

Range

Yes you get more range ; 18650 have much better power density - but for us we went down the avenue of higher power delivery battery packs which can deliver a more powerful punch when you hit that bump - no one else is using those cells are the other wheels are not made to cater for Europen heavy riders. We might release an upgraded battery pack later on in the year which would be a direct swap but it all depends on how well it passes our assessments 

 

For or a commute with steep hills I would really recommend using 2 of our power packs and swap them mid way through rather than one pack - I have tested both options

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On 05/04/2016 at 6:37 PM, Gimlet said:

One leg is fine, it only stops the motor when there's no leg either side.

The pedals on the one I rode were fine, a bit bigger than the mcmv2s ones but not so big as to stick out and catch the ground in the turns.

That must be some pretty hefty nail varnish, or are you buying it in bulk? :)

They had lots of plates with different designs on, I knew I would pick the wrong one so bought all of them. It's my eldest daughters birthday in May & I figured all of the women in the family could use it. My missus is happy with it, apparently it's the kind of thing people set businesses up with so is quite professional.

 

I look forward to your review of the wheel. I still feel guilty for forgetting to take a present for them as they provided me with my ticket.

On 05/04/2016 at 7:05 PM, Keith said:

If you think about it, the wheel has to power up as soon as you have one foot on it or you couldn't step on to it with the other foot. See 5:27 into this video for a (rather painful!) demonstration of one legged Uniwheel riding:

"I had already forked out £250 for nail varnish". You do know painting an elephant's toenails red so it can hide in a cherry tree is just a joke don't you?

 

Lmao. I haven't heard that one, I thought they were only up there until Autumn when they could come down on a leaf :-D

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45 minutes ago, KingSong69 said:

@Eryk88

 

sorry!

you have to explain that....so a watthour is Not a watthour anymore???

 

You have to differentiate between Power (W) and Energy (Wh). Energy (Wh) is the sum of "delivered" power over time. Power (W) is just the "power" (current times voltage) the battery delivers at a specific moment.

So @Eryk88states that their pack, despite being smaller (in terms of Energy (Wh)) can deliver more continous power at any given moment (before the pack is empty - all Energy consumed). 

So with continously delivering 3600W the 132Wh pack would be empty within 132Wh/3600W  = 2,2 minutes. With some normal 200-300W power consumption while driving it should last about 30-40 minutes. But the pack can deliver (almost) anytime the 3600 W to balance you instead of faceplanting with a pack that only can deliver 1800, but this for a much longer time... So with a low power high energy pack you could drive after the faceplant still to the hospital - with the high power low energy pack you maybe would not make it to the hospital, but you did not have a faceplant anyway ;)

ps.: Their used ?LiFePos? have a lower energy density compared to the normal used LiIons in EUCs - so the same size pack with LiFePos has less Wh. But as it seems they can deliver about 70/(30/2)=4,6 times the current (One A123 LiFePo cell compared to one LiIon cell). 

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Don't know if it's the 18650-form factor or something else, but here's the A123-overview:

http://www.a123systems.com/lithium-battery.htm

Apparently they use some form of improved LiFePo ("nanophosphate").

Power (not energy!) density of A123 18650

Nanophosphate® LiFePO4 Benefits:

  • Power: Over 1850 W/kg and 4400 W/L
  • Safety: Excellent abuse tolerance and environmentally friendly
  • Life: Excellent calendar and cycle life

 

Of course I couldn't find a proper picture showing differences between different lithium-chemistries, but this should suffice for a rough comparison, although I suspect it might be a bit outdated (A123 = smaller specific energy = energy density, higher specific power = power density):

 

ncomms2747-f3.jpg

ev1.jpg

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21 hours ago, Eryk88 said:

 

Yes you get more range ; 18650 have much better power density - but for us we went down the avenue of higher power delivery battery packs which can deliver a more powerful punch when you hit that bump - no one else is using those cells are the other wheels are not made to cater for Europen heavy riders. We might release an upgraded battery pack later on in the year which would be a direct swap but it all depends on how well it passes our assessments 

 

For or a commute with steep hills I would really recommend using 2 of our power packs and swap them mid way through rather than one pack - I have tested both options

Have you ever considered a hybrid approach? Keep the 170wh of A123 and use high density low discharge  li ion to charge the A123?

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Sorry again!

for me this is all Nonsense....

watthour describes The Time the Batterie is able to deliver a given amount of power!

so 100wh is always 100wh!

for One Hour The pack is able to deliver 100Watt....

the energie Density is another thing...you Are able to pack more wh in a cm2 ...sure!

voltdrop is another thing...sure!

lipo packs Are able to deliver high Amps without dropping...

so for me the only way uniwheel is able to get More out of lets say a 132wh pack ...is Having a Motor which Consumes less power(Watt)...

but then there is the Next Problem: less power :-)

ok...Could be with the uniwheel you Are able to climb 2 seconds a 90degree hill...or you Are able to lean over ultraextrem for a second:-

but then you have to change Batteries?

wow! What an advantage :-)

really...good-nice Wheel...but i can Not understand how nowerdays a "top" Wheel in this pricerange can Go with something under 340wh....but Perhaps i am too stupid to understand :-)

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58 minutes ago, KingSong69 said:

 

watthour describes The Time the Batterie is able to deliver a given amount of power!

so 100wh is always 100wh!

for One Hour The pack is able to deliver 100Watt....

the energie Density is another thing...you Are able to pack more wh in a cm2 ...sure!

voltdrop is another thing...sure!

Basically it can output the high currents that a normal 640wh 4p set up can but it doesn't have the same range.

However on a generic 134wh unicycle you will find it becomes near impossible to ride at about 50% battery power leaving you with only 90wh of battery you can actually use. While the uniwheel should perform until the battery is flat. In practical terms I imagine range is similar to 260wh  li-ion packs.

It would depend on conditions though, a light rider on flat terrain might be able to ride a li-ion EUC all the way to battery cut off, while a heavy rider climbing hills may find the li-ion EUC impossible to ride with 60% battery remaining.

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Just because a battery is rated in your example at 100Wh doesn't mean that it can deliver 100w for an hour, it may only be capable of delivering 50w but for 2 hours or maybe 25w for 4 hours.

This obviously has a huge effect on the power the motor can deliver. In reality batteries can normally give a very high output for a short time but the output tails off quite sharply due to internal resistance.

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It was this time limit on high output from batteries that original made many people who realised the battery limitations, me included recommend getting the biggest battery available on any wheel you purchase no matter what range you require.

If you can get a bigger draw for longer off of a smaller battery that has a different chemistry then for many it saves having to carry the weight of a huge battery when you don't really need the range.

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1 hour ago, KingSong69 said:

...

so for me the only way uniwheel is able to get More out of lets say a 132wh pack ...is Having a Motor which Consumes less power(Watt)...

Or consumes high power tor a shorter time frame : E = P * t - you can change P or t for a fixed E.

Quote

ok...Could be with the uniwheel you Are able to climb 2 seconds a 90degree hill...or you Are able to lean over ultraextrem for a second:-

 

I assume the 70A @Eryk88states are the continous current from the datasheet - so the pack should be able to provide more or less the full power till the end...

Quote

" Wheel in this pricerange can Go with something under 340wh....but Perhaps i am too stupid to understand :-)

Thats for LiIons - thete it is very recommandable to choose at least a 16s2p pack and not an 16s1p. LiIons are for now capable of dlivering between 15-20A max continous current - so with a 16s2p pack you get 30-40A, which as about enough  for good driving, but could still be a little bit at the limit.

And with current pack configurations 16s2p packs have around 320-380Wh

30 minutes ago, Gimlet said:

Just because a battery is rated in your example at 100Wh doesn't mean that it can deliver 100w for an hour, it may only be capable of delivering 50w but for 2 hours or maybe 25w for 4 hours.

Especially for LiIon - with 16s2p packs riding with full batteries goes very well, but as soon as the battery gets more empty faceplanting gets more propable.

but the rated max continous current should be available more or less for the whole time - if you look at the dampfakku.de test discharge rates! So with for example 15A max continous current a 16s2p should be able to delive ~55*30W=1650W all the time! I assume that peak currents can't be delivered anymore?

Imho LiFePos are supposed to show better "performance" in this respect - but time will tell, or an experienced forum user?

Edit: I think solowheel has quite such a battery setup as uniwheel - low range but powerfull, from the seldom posts/reports from solowheel riders i have read here so far? One reseller stated also LiFePos for Solowheel?

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51 minutes ago, lizardmech said:

However on a generic 134wh unicycle you will find it becomes near impossible to ride at about 50% battery power leaving you with only 90wh of battery you can actually use.

I currently ride a generic 132wh EUC and do not see any decrease of performance when the battery is less than 50%.

But I'm aware and do not push hard when the energy is near the end...just in case.

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23 minutes ago, Chriull said:

Edit: I think solowheel has quite such a battery setup as uniwheel - low range but powerfull, from the seldom posts/reports from solowheel riders i have read here so far? One reseller stated also LiFePos for Solowheel?

I'm fairly certain Solowheel stopped using LiFePos in Xtreme & newer "Classic" and the current chemistry is NMC. Only the oldest models have LiFePo's? And AFAIK, they're not the A123 cells like here, but more "traditional" LiFePos that have much lower specific power.

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