💪 EUC pull force test results - reviewers please do this!

[GoGeorgeGo]

On 5/10/2022 at 12:52 PM, RagingGrandpa said:

Results:

(More models coming soon...)

Why is this interesting?

Pull force shows the maximum acceleration that an EUC can create from a standstill. 

I hope we can get EUC reviewers to measure prototype wheels in the future. 
@Marty Backe @Hsiang @evX_Mick @colton @Jack ex-KS @Afeez Kay @Jason McNeil @Alien Rides @GoGeorgeGo @ray rokni @Mike Sacristan

 

Honored you would inlcude me in that group but so far i only have access to my personal wheels and my friends wheels. I may get a chance to test some wheels in the future but for now im just a vlogger really. 

I need to get back on my game and start posting twice a week again. 

I do like that this is a more analytical analysis data point than just feelings and opinions though. Its so hard to really do a range test thats fair or to truely impart the feelings of a wheel based on just words.

[RagingGrandpa]

Abrams!
... ended up basically the same as Sherman.

Their lift speeds and system voltages are the same, so I would have expected a lower pull force from the larger-diameter tire. Interesting.

Still makes me chuckle that it was marketed as an offroad wheel, since the MSX's from late 2018 best it.

And I discovered that Abrams will "give up" after 1 second during the pull test, which none of the other EUCs do. Hmm... 
More on that in the Abrams FW thread.

[RagingGrandpa]

Busy day... my metro-Detroit riders have been super cool about letting me measure their wheels  

Sherman Max: truly stronger than the original Sherman, nice!
Although I'm not super excited about this new firmware (like Abrams) that gives up after just 1 second at the limit.

S18: Weaker than MSX, as expected. But stronger than V11, a nice surprise.

18L (not XL): Stronger than I expected for a very old wheel.

Nikola+: Weak, especially considering the 16" tire.
Maybe new controllers crank up the amps more than my first-batch version?

Onewheels: Are funny- I didn't even have to stand on them. Pushing downward with hands was sufficient...

[Denny Paul]

@RagingGrandpa just wanted to say I very much appreciate reading your posts that have a thoughtful methodology to them. I don't know if any youtuber is going to pick this up, I think the average person doesn't have the patience to test or play with data like this. 

These threads are the kind of gems I'm hoping for when browsing the forums. Thank you. I hope you continue with more models!

[mike_bike_kite]

@RagingGrandpa Really interesting data. Do you mind if I put a field in my EUC database to hold this?

[RagingGrandpa]

17 hours ago, mike_bike_kite said:

Do you mind if I put a field in my EUC database to hold this?

Yes of course, all are welcome to use the information from this thread  

On 5/29/2022 at 8:22 PM, Denny Paul said:

I don't know if any youtuber is going to pick this up, I think the average person doesn't have the patience to test or play with data like this.

Right, maybe the "big table of results" is too cluttered...

But what I'm hungry for is a sentence like this, from @Marty Backe or @Hsiang etc: 
"We found the Master 134V pulls XX pounds harder than the previous strongest EUC, Begod RS C38"

(Wouldn't that be great? )

[alcatraz]

Man, this is a great test. It would be good to encourage people to test wheels that are already in the list. More measurements increase accuracy.

It would be amazing to do this but at speed. How much of that 0 speed torque is left at X mph? Good question.

[Rich Sam]

1 hour ago, alcatraz said:

Man, this is a great test. It would be good to encourage people to test wheels that are already in the list. More measurements increase accuracy.

It would be amazing to do this but at speed. How much of that 0 speed torque is left at X mph? Good question.

I would imagine we would need some kind of a Dyno rig for that.  But that data would be cool to have.  It is said the legacy sherman had a second gear at around 20 mph, Dyno could prove that.

[Boris Lämpel]

I cannot see the use of this test. For most of us we are riding our EUC, not standing still and leaning.

The idea is not bad, but to get any useful results we would need the power during different rotation speeds. For example the Sherman or the S20/22 have more torque (as long as You can feel it) to accelerate from a certain speed than in a standstill.

[mike_bike_kite]

21 hours ago, RagingGrandpa said:

Yes of course, all are welcome to use the information from this thread  

I've put the data into the database and anyone can add new data. I also added a small report showing fastest accelerating wheels but obviously that only shows for wheels we have data for. It's mildly annoying the data is in lbs as most of the other data is in metric but hey ho. Would wheels with the same motor, voltage and tyre diameter have the same numbers or does battery capacity come into it also? I'm asking because I copied the Nikola numbers to the Nik Plus AR and Nik Plus 18650 then wondered whether that was correct. Would the KS18XL be the same as the 18L?

Edited June 1, 2022 by mike_bike_kite

[RagingGrandpa]

8 hours ago, Boris Lämpel said:

we would need the power during different rotation speeds.
For example, [does] the Sherman, or the S20/22, have more torque to accelerate from a certain speed than in a standstill?

If dynamometers were practical, we would use them... but they're not. 
Don't let perfection distract us from useful ways  

And I truly believe stall current is the maximum motor current the EUC can deliver. And the pull test reveals it.
(It would take direct measurement of motor current during riding, to convince me otherwise.)
 

3 hours ago, mike_bike_kite said:

Would wheels with the same motor, voltage and tyre diameter have the same numbers

Only if they use the same firmware. Because firmware determines the current limit, and current creates force.
 

3 hours ago, mike_bike_kite said:

does battery capacity come into it also?

Assuming the same firmware, no.

Having a smaller battery pack implies more voltage sag during the pull test. 
Sag usually doesn't matter here, because there is still ample voltage available to reach the firmware current limit. 
As I mentioned in the FAQ, I compared results for different voltages (simulating sag) and found no change in motor current nor pull force.
 

3 hours ago, mike_bike_kite said:

I'm asking because I copied the Nikola numbers to the Nik Plus AR and Nik Plus 18650 then wondered whether that was correct.

Ah. That early-build Nikola result seems fishy to me, that it only allowed 200A, when the MSP goes to 250. 
(Those numbers did end up matching Freestyler's expectation amazingly closely.)

I still wonder if that 200A limit is based on the 84V Nikola, and the newest-firmware 100V Nik+ and NikAR might very well improve upon it. 
I'll test a newer Nik, next chance I get... better to treat those as 'unknown' until then.

 

Edited June 1, 2022 by RagingGrandpa

[yoos]

Great work and the first rider-independent performance test (actually the first would be free-spin speed test but that's quite trivial)! This is a much more reliable and meaningful metric than the nominal+peak motor power advertised by manufacturers. It also measures direct output instead of trying to derive things relying on self-reported EUC data (which doesn't even take into account all kinds of inefficiencies and nuances). You can also use it to roughly predict low-speed hill-climbing capability.

And just personally I like how well my 18L pulls its weight. I guess the same result for the S18(p42a) indicates that the firmware in those "special edition" S18s is not special at all and allows the same current as a regular S18. Either this could be improved or there really are some other bottlenecks in the S18 (board? wiring? The motor is rarely the bottleneck).

On 6/1/2022 at 10:15 AM, Boris Lämpel said:

The idea is not bad, but to get any useful results we would need the power during different rotation speeds

As @RagingGrandpa already answered, this test gives the maximum force F_m the EUC can produce. I guess as a rough rule of thumb you can estimate the force at speed v as F(v)=F_m (1-v/v_m) where v_m is the free spin speed. Though many EUCs seem to have a plateau at the beginning (due to an imposed limit on current), and I also suspect that the true v_m in the formula might be higher than the free spin speed (that would be the case if the board stops accelerating the EUC at some preset speed rather than at the theoretical maximum v_m). 

Edit: typo in formula

Edited June 2, 2022 by yoos
typos

[Freestyler]

3 hours ago, RagingGrandpa said:

Ah. That early-build Nikola result seems fishy to me, that it only allowed 200A, when the MSP goes to 250. 
(Those numbers did end up matching Freestyler's expectation amazingly closely.)

I still wonder if that 200A limit is based on the 84V Nikola, and the newest-firmware 100V Nik+ and NikAR might very well improve upon it. 
I'll test a newer Nik, next chance I get... better to treat those as 'unknown' until then.

My Nikola data are for the 100v version.

Begode released firmwares for the Nikola 2700 and hero c30 so I took a look.

They seem to be the newer style firmwares that allow for lower battery discharge until the final tiltback.

Nikola 2700 still has 200a current limit but discharges all the way down to 3.0v.

Hero C30 has 240a current limit and discharges all the way down to 3.1v.

 

The firmware values seems to match your tests a lot to just be a coincidence so we can adjust the limit in a custom firmware and see if it has an impact.

Let me know if you want to test such a thing.

[RagingGrandpa]

1 hour ago, Freestyler said:

we can adjust the limit in a custom firmware

Begs the question, "who would benefit from higher current?"

I think if you were racing EUC's on pavement, Master with 275A firmware would win the day, with an accordingly aggressive rider. That's who.

My MSP with its 200lb pull force does everything I need it to do on MTB trails, so increasing its limit wouldn't help me personally. 
(Although increasing voltage while keeping the same 250A output would be meaningful, increasing its speed range.)

Nikola isn't normally used as a mountain climber, so I think its conservative current threshold doesn't really bother anyone.
 

And why wouldn't Gotway configure the new C38 Master to the same limit as C38 MSP?
Especially since its new controller makes less heat than the old MSP. 
The Master's motor cable is much longer (bad), but has airflow (good) that the MSP lacks.
Other reasons perhaps...

[FunTech4Real]

I really want to see how a regular S18 compares to the molicel version in this test.... so far only the molicel version is tested so hopefully it should be easy to get a regular S18 tested. 

[yoos]

1 hour ago, sevin7 said:

how a regular S18 compares to the molicel version in this test

Honestly I expect the same result for the stall pull force (probably due to having the same firmware). I guess the Molicel shines at non-zero speeds where it doesn't show voltage sag.  

[Denny Paul]

On 6/11/2022 at 7:04 AM, sevin7 said:

I really want to see how a regular S18 compares to the molicel version in this test.... so far only the molicel version is tested so hopefully it should be easy to get a regular S18 tested. 

Even though they have different motors, I see the 18L has such a similar result to the molicel’d s18. For me, it suffices as a substitute to reasonably guess that the molicel packs do not increase peak pull. 

[supercurio]

@Denny Paul don't the 18L, 18XL, 16X, S18 have the same motor?

(Only the 16X being having a 12" rim instead of 14“)

S18 and 18L getting the same result shows that if the motor is indeed the same, the controller limit for phase current is also identical.

Now since the S22 also has the same motor, what will the results be... (hopefully more phase current is available here)

[FunTech4Real]

4 hours ago, supercurio said:

@Denny Paul don't the 18L, 18XL, 16X, S18 have the same motor?

(Only the 16X being having a 12" rim instead of 14“)

S18 and 18L getting the same result shows that if the motor is indeed the same, the controller limit for phase current is also identical.

Now since the S22 also has the same motor, what will the results be... (hopefully more phase current is available here)

Where do you get your information that the S22 has the same motor as the old EUCs? The S22 is the first EUC I've seen with a very custom looking motor design... by that I mean he metal enclosure of the motor and the rim look custom and very different from past EUCs

[supercurio]

@sevin7 the source is Ecodrift's S22 teardown:

Quote

Standard motor configuration from S18/18L/16X to 54 teeth with 60 magnets on the rim

The rim itself is different, and the motor was transformed from being held from a central axle to a hollow bore configuration, but everything else (what really matters) appears to remain unchanged according to their description.

So any additional pull force compared to the S18/18L/18XL would be thanks to higher phase current.
Based on tester's feedback, what to expect: something in the range 170-180 lbs?

Edited June 13, 2022 by supercurio

[Denny Paul]

9 hours ago, supercurio said:

don't the 18L, 18XL, 16X, S18 have the same motor?

The early 18L's came with a "2000w" motor. This wasn't just advertised on websites, but also seen as a stamp on the motor itself. Later in production they switched to the 2200w motor, aka the zx motor (as that's what the motor serial number started with). This was at the same time as the 16x launch. 

Older 18L and 18xl = 2000w motor

newer 18L, 18xl, all s18's, all 16x's = 2200w zx motor

My interpretation of the data is that the controller limits are the same despite different motors. 

[supercurio]

Ah that's right @Denny Paul, do you remember if someone made a comparison teardown of both the 2000 and 2200W-rated motors?

And did people at the time change motor, expecting an increase in power? - (I guess not since it is 100% determined by the controller)

It would be cool to compare an old 2000W rated 18L and current 2200W rated 18L to see if there's differences.

[RagingGrandpa]

Added Tesla and Monster Pro, no real surprises in their results.

Tesla's tiny tire doesn't have the traction of the larger EUC's, it was difficult to put enough weight on it to prevent burnout while pulling  

[supercurio]

Really interesting @RagingGrandpa! So with the small bearings that's the 2nd revision of the Monster Pro, sometimes called "high torque" or at least higher torque than the first one, and it essentially matches the Sherman.
I look forward to this being confirmed by numbers once measuring a 1st revision Monster Pro.

The Telsa test makes me wonder what happened with the Nikola 100V one, which doesn't seem to match its steep, very low speed climbing performance vs the Tesla.
Comparable circumference tire (although a bit larger on the Tesla) and almost the same phase current. Is the Tesla motor a lower Kv rating?

Edited June 13, 2022 by supercurio

[Denny Paul]

2 hours ago, supercurio said:

do you remember if someone made a comparison teardown of both the 2000 and 2200W-rated motors?

And did people at the time change motor, expecting an increase in power? - (I guess not since it is 100% determined by the controller)

No, I've never personally seen an objective teardown of the differences.

Anecdotally, having ridden both I can say they feel about the same. If there's a difference, it isn't a huge and glaringly obvious one.