Kingsong S20/S22 (Confirmed)

[Tawpie]

It's always tough comparing marketing specs against real world experience... the marketeers never tell the whole truth, and real world will always have its outliers. I succumb to the temptation to try to boil an entire system down to 1 or 2 soundbites when I know from being bloodied in battle that a system is much more than 1 or 2 'features'. My car might have y speed rated tires on it, but it doesn't matter much if the operator won't take it above 80 mph because of insurance.

For my off roading where the surface is unpredictable I find that I want fine torque control more than pure unadulterated torque. But I don't try to climb logs or 50° slopes. On the drag strip, you have a better chance of actually making use of pure power... up to a point.

Edited March 24, 2022 by Tawpie

[Planemo]

1 hour ago, RagingGrandpa said:

 Adding more together in series would nearly double the physical size of the controller... not a great option. 

So be it. The controllers are going to have to get bigger anyway. Riders are constantly pressuring for more power, they can't have it both ways. People bleat about components being inadequate but will then moan about controller size if they lose some battery space or have to run a bigger wheel.

I don't agree with EUC's getting faster/more powerful as I don't want them to turn into (and be viewed by the public as) one wheeled motorbikes, but it is what it is. Much of what I see nowadays is riders giving it large about speed, riding like lunatics then posting it all over the web and it depresses me a bit. I realise I am in the minority with my view though so I just have to deal with it.

[chanman]

I think some of y'all may have missed there's 12 fets in total, 4 in parallel for each phase, so each one is only sharing 1/4th of the current, and for heat dissipation purposes are only on 1/3 of the time for the 3 motor phases, this helps a lot.

 

On further review of how to actually drive these motors I guess 4 per phase is actually only with 2 in parallel, so not quite as reassuring on the power numbers as I would have liked.

Edited March 25, 2022 by chanman

[mrelwood]

11 hours ago, chanman said:

I think some of y'all may have missed there's 12 fets in total, 4 in parallel for each phase, so each one is only sharing 1/4th of the current, and for heat dissipation purposes are only on 1/3 of the time for the 3 motor phases, this helps a lot.

 

On further review of how to actually drive these motors I guess 4 per phase is actually only with 2 in parallel, so not quite as reassuring on the power numbers as I would have liked.

4 mosfets per phase are probably connected in a H-bridge like this:

In which case no mosfets are parallelled at any time.

EDIT: Turns it I was wrong about this! The above image is not what is used in EUCs.

Also, in my understanding basically all current wheels are driven with a sine wave signal, which would barely ever be completely off. The peak current is of course only present at a very narrow timeframe as well:

(Trapezoidial/square wave on the left, sine wave on the right.)

Edited March 25, 2022 by mrelwood

[Hansolo]

The motors of our wheels have 3 phases, it is necessary to add 2 mosfet to this diagram thus 6 mosfet in all

To accept more current each mosfet are doubled in // which gives 12 mosfets (even 3 mosfets in // on the Monster Pro from Begode)

[mrelwood]

4 hours ago, Hansolo said:

The motors of our wheels have 3 phases, it is necessary to add 2 mosfet to this diagram thus 6 mosfet in all

To accept more current each mosfet are doubled in // which gives 12 mosfets (even 3 mosfets in // on the Monster Pro from Begode)

The four mosfets in the graph above are all for a single motor phase. Each of the three phases have the same four mosfets. 4x3=12. Nothing is doubled in this 12 mosfet design.

EDIT: Turns out I was wrong!

Edited March 25, 2022 by mrelwood

[Hansolo]

[Miko.cz]

I would like to add one more argument to range tests - differences in results we see with S20.
I have done 2 rides on KS-16S (680Wh) exactly same track. Difference in battery left is 16%, with this small battery and double plastic shield of EUC (compared to massive Alu heatsink on S20).
Battery charged to max + balanced. Data:

1. EUC World:4°C + 88kg brutto + 20.3km/h avg + weak frontal wind (open areas only) + 1h 26m
2. EUCWorld: 17°C + 85kg brutto + 21.6km/h avg + no wind + more aggresive ride + 1h 23m

Note: thanks KS for headroom, at 8km I jumped into the pot hole (exactly jumped to the edge of the end of pot hole). 16S protested heavily but fortunately I was not examinating road more closely.

[Chriull]

2 hours ago, mrelwood said:

The four mosfets in the graph above are all for a single motor phase. Each of the three phases have the same four mosfets. 4x3=12. Nothing is doubled in this 12 mosfet design.

Not for a single motor phase but for a single phase motor with the possibility for reverse operation. Otherwise (single direction) 2 mosfets would be enough.

Our 3 phase bldc motors are driven, as posted by @hansolo with 6 mosfets. (Direction change is here accomplished by the commutation - no more mosfets necessary)

So our 3 phase bldc always need multiples of 6 mosfets.

Edited March 25, 2022 by Chriull

[mrelwood]

2 hours ago, Chriull said:

Not for a single motor phase but for a single phase motor with the possibility for reverse operation. Otherwise (single direction) 2 mosfets would be enough.

Our 3 phase bldc motors are driven, as posted by @hansolo with 6 mosfets. (Direction change is here accomplished by the commutation - no more mosfets necessary)

So our 3 phase bldc always need multiples of 6 mosfets.

Thanks for this, I had understood the whole motor operation wrong! I’ve got me some more reading to do.

Edited March 25, 2022 by mrelwood

[Rollin-on-1]

Apparently the new FW is out - ver 2.17.  This is the one that is supposed to improve accelleration.  Ginger on wheels (Ryan Strahl) is downloading it and will hopefully be reporting out on it sometime soon!  Could this new version bring the performance that so many have expected all along?

[Tawpie]

9 minutes ago, Rollin-on-1 said:

Could this new version bring the performance that so many have expected all along?

or, will we see our first control board go 'poof' followed by the traditional dumpster fire we all know and love? 

[Rollin-on-1]

14 minutes ago, Tawpie said:

or, will we see our first control board go 'poof' followed by the traditional dumpster fire we all know and love? 

I certainly hope that isn't going to happen.  If KS releases a FW update that leads to a poof, that would likely result in many pre-order cancelations.

[Tawpie]

3 minutes ago, Rollin-on-1 said:

I certainly hope that isn't going to happen.  If KS releases a FW update that leads to a poof, that would likely result in many pre-order cancelations.

Perversely, I'm sort of hoping for poof. I like to see testing to destruction—it gives you a more accurate view of the real life limit (IFF the system is instrumented so you know what was really happening!)

On the other hand, GoW is a local rider and I do not want him to get hurt!

Edited March 25, 2022 by Tawpie

[Rollin-on-1]

20 minutes ago, Tawpie said:

Perversely, I'm sort of hoping for poof. I like to see testing to destruction—it gives you a more accurate view of the real life limit (IFF the system is instrumented so you know what was really happening!)

On the other hand, GoW is a local rider and I do not want him to get hurt!

I prefer all poofs to happen in factory testing settings before FW release to the public vs with real-life test dummies.

[Kristof Willen]

I had a chance to test drive the S20 today.  Here are my findings:

(Disclaimer : I currently ride a Nik+, never rode a wheel with suspension.  Total EUC experience = 10.000km)

• It is a really beautiful and impressive looking wheel
• This thing is large and heavy.  Steers like a large truck.  Turning on the spot seems almost impossible.  The engine is still powerful enough to give enough torque so accelerating is still quite good.
• The wheel is wide, but not so that it is cumbersome. 
• Pedals are high !
• I love the pads ! I really like the pads - so much that when I hopped back onto my Nik+, I immediately missed them.  
• The handle sucks.  I'm 6 ft tall, it is way too low to steer it comfortably, and combined with the heavy weight makes it difficult to maneuver.
• I really like the giant spiked pedals

conclusion : quite disappointed with the heavy steering feeling, I was looking to replace my Nik end this year with an S20, seems I'll hold on to my current wheel for another year or so...

[Forwardnbak]

I think it’s nice that the firmware is being improved prior to shipping not just rushing them out and patching things later.

I'm sure they still will. 

More I’m just impressed with how they have handled this wheel, slow release of info and product previews with full open testing, real world conditions feedback to find flaws and improvements along the way. 
To me it’s reassuring they are giving it this attention. 

[Rawnei]

19 minutes ago, Kristof Willen said:

conclusion : quite disappointed with the heavy steering feeling, I was looking to replace my Nik end this year with an S20, seems I'll hold on to my current wheel for another year or so...

I bet you this is just a matter of getting used to different characteristics, plenty of videos of people dancing ballet on this thing. 😁

Pedal height can be adjusted both at pedals and on suspension linkage.

[Tawpie]

24 minutes ago, Kristof Willen said:

Turning on the spot seems almost impossible.

Yeah. For me, that's just not going to be a thing, I don't bring enough rider mass to use against the wheel mass. A tight yaw+lean turn while moving had better be possible though. I had to relearn tight turns on my S18 with the TR1 tire, that combo doesn't turn well on pavement. Off road it's fine but compared to my 16X/H666 the S18's higher center of mass coupled with the increased weight and flatter tire profile required learning new techniques.

[Rollin-on-1]

9 minutes ago, Tawpie said:

 but compared to my 16X/H666 the S18's higher center of mass coupled with the increased weight and flatter tire profile required learning new techniques.

This is my concern as well.  The 16x with H666 pumped up over 40 psi is delightfully lively. Bigger heavier wheels just feel sluggish and cumbersome by comparison.  I did find the S20 more enjoyable than the OG Sherman with the 262 however, which gives me hope that the S20 will satisfy me once I have given it a bit of an adjustment period.

[fbhb]

Ecodrift's teardown YouTube video.

[OldFartRides]

Great vid. Well done. Esp. the squeaky fire breathing bagpipes.

[supercurio]

Great new vid from Adam / Wrong Way.

He likes the wheel a lot more than before now in its lowest suspension setting, although he lowered it so much that pedal scrapes seem to happen easily.
The CST-C186 knobby is much more to his liking than the stock knobby which he disliked very much.
On that day he flashed the new firmware and it appears to improve responsiveness subjectively.

Then in the end Adam tries going up stairs, which is the situation where he noticed pedal dipping accompanied with a clonk sound could happen.
First it seems it doesn't happen anymore, but once he accelerates more over the step it does again.

He reproduces the issue there's a slow-motion (50 fps source) where the pedals dip, forward, but at the same time the tire spins out until regaining traction and when it does, the wheel brutally re-balances which might be the cause of the clonk sound.
It's hard to tell if the wheel dips because it runs out of torque or out of traction when the tire bounces back&up against the step.
I asked in the comments if he could try to film again at 240 fps which he said he would!

 

 

Edited March 26, 2022 by supercurio

[Rollin-on-1]

22 minutes ago, supercurio said:

Great new vid from Adam / Wrong Way.

I'm liking what I'm seeing out of the new FW.  I can't wait to see how the S20 performs with a street tire!  Hopefully he will try out a C6004. I'm leaning hard toward putting it on my S20 based on what I've heard others say about it.  I don't go with the C6004 then I'll likely go with the H666.

[Rawnei]

I have Clark Pads and all that but will roll with a stock setup for a while and evaluate how that is (minus the boomerang I think that thing is just in the way to adjust the pads fully), I want to give both the pads and the tire a chance and benefit of doubt and not just swap them.