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

[RagingGrandpa]

On 8/16/2023 at 4:40 PM, RagingGrandpa said:

https://www.facebook.com/groups/inmotioneuc/posts/3145870532374568/

850N, now you're speaking my language!
Added to the table now.

191 lb would be quite strong... hope real-world tests support it.

 

Edited November 1, 2023 by RagingGrandpa

[DjPanJan]

I hope in patton or other new torque line euc how realy perform in this great test.

[2cells1pack]

I just ordered the parts do to these pull tests - hopefully can have something rigged up next week. I can test a lot of the new wheels as I work with eevee's as a technician. I'll also make a video on it for youtube and keep a listing somewhere.

[DjPanJan]

1 hour ago, 2cells1pack said:

I just ordered the parts do to these pull tests - hopefully can have something rigged up next week. I can test a lot of the new wheels as I work with eevee's as a technician. I'll also make a video on it for youtube and keep a listing somewhere.

I love 2cels1pack content YT just pure efective informative. I be happy if you can test patton and other untested EUCs.

 

[Rawnei]

2 hours ago, 2cells1pack said:

I just ordered the parts do to these pull tests - hopefully can have something rigged up next week. I can test a lot of the new wheels as I work with eevee's as a technician. I'll also make a video on it for youtube and keep a listing somewhere.

Nice to have you here, pull tests will be much appreciated.

[RagingGrandpa]

Patton! Exceeded expectation! 

[2disbetter]

On 5/10/2023 at 5:06 PM, mrelwood said:

V13 limits the power quite strongly at standstill (like many/most/all? non-Begode based wheels do), so it won’t get good results in this test. 

That kind of messes with the validity of such a test. I mean I was under the impression that the V13 has one of the most powerful motors in it, but if the software is limiting output at a standstill then the accurate numbers of that power wont be found. Still if we are concerned about standstill upmf this is a good chart. I am really curious what the V13 motor can really do. 

[Rawnei]

10 hours ago, RagingGrandpa said:

Patton! Exceeded expectation! 

Wow, super stronk!

[Punxatawneyjoe]

5 hours ago, 2disbetter said:

I am really curious what the V13 motor can really do. 

I have to re-do the test after unlock, also after i was removing the string i noticed it had wedged itself between the motor and the slides on both sides and it was bound pretty bad so definitely had major resistance. I will change the mount point on the next test.

[RagingGrandpa]

More results added:

• EX30 new firmware: looks like they're allowing 300A now, which brings it ahead of Sherm-S again 
  And I was surprised to see offroad mode had more pull. I presume both modes (race vs offroad) have the same current limit, so this hints at a major difference in the motor control algorithm. Neat.
• Commander Mini: Great result! These new 16" wheels are grunty!
• Master with the newest controller: more than expected, good to see. 

I also saw from the EUC World logfiles that I was only getting a 1Hz sampling rate for the 3 wheels above. Yet I still get 4 or 5Hz with older Gotways. 1Hz is too slow to reliably reveal the motor current peak during this test, so I've left some "?" markups in the results table on the motor current values that I think aren't realistic.  
I'll try other settings in EUC World next time, too...

[Bizra6ot]

You're right

[ 1 ] Added race mode and off road modeOn the race mode, if one leans forward, it will accelerate quickly and greatly, and reduce wobbles. It will be accelerated more smoothly and efficiently.And it will uses less electricity.As for the off-road mode, you will get more torque and power. https://www.facebook.com/groups/ElectricUnicycle/permalink/6447213445376564/

They were also recently testing 350A, to the moon  

 

[smash]

I was expecting a higher value for the v12ht, especially since everyone raves about its 'limitless torque'

[mrelwood]

13 hours ago, smash said:

I was expecting a higher value for the v12ht, especially since everyone raves about its 'limitless torque'

Inmotions traditionally have a pretty strict current limiter when stationary, which is the problem with this test. It only tells you how strong each wheel is when stationary. Once you get going, it’s a whole new ball game.

[Punxatawneyjoe]

1 hour ago, mrelwood said:

Inmotions traditionally have a pretty strict current limiter when stationary, which is the problem with this test. It only tells you how strong each wheel is when stationary. Once you get going, it’s a whole new ball game.

Agreed, just found my results from my pull test that day and they are very sad. I was pulling over 12k w yesterday on an acceleration and that day less than 4.1k

I will try to unlock fancy mode next month and re-do the test.

[smash]

7 hours ago, mrelwood said:

Inmotions traditionally have a pretty strict current limiter when stationary, which is the problem with this test. It only tells you how strong each wheel is when stationary. Once you get going, it’s a whole new ball game.

I wonder if the reason leaperkim decided to have almost no current limit at stationary (or none at all, curious if someone knows this detail) for the patton is because there are no gaps in the rim for branches or sticks to get stuck in.

Edited October 2, 2023 by smash

[mrelwood]

3 hours ago, smash said:

I wonder if the reason leaperkim decided to have almost no current limit at stationary (or none at all, curious if someone knows this detail) for the patton is because there are no gaps in the rim for branches or sticks to get stuck in.

I don’t think it’s related to that. All 16” wheels have the rim right at the edge of the motor, so there are no spokes.

 When (near) stationary, the currents can get very large just because of how all BLDC motors are designed. In the past it was relatively common for the boards to fry when starting to ride from behind a stick or such. With the power the new wheels have, the currents are even a few times larger. It makes sense to limit them when near stationary.

[smash]

12 minutes ago, mrelwood said:

I don’t think it’s related to that. All 16” wheels have the rim right at the edge of the motor, so there are no spokes.

 When (near) stationary, the currents can get very large just because of how all BLDC motors are designed. In the past it was relatively common for the boards to fry when starting to ride from behind a stick or such. With the power the new wheels have, the currents are even a few times larger. It makes sense to limit them when near stationary.

That makes sense. So this change just comes down to the components in new wheels being able to take higher currents? I don't imagine the patton goes much higher than 300A when in motion. (nevermind its max current is listed as 680A 🥴)

Edited October 2, 2023 by smash

[RagingGrandpa]

3 hours ago, smash said:

leaperkim decided to have almost no current limit

There is a firmware-enforced motor current limit. For all modern EUCs. 

The difference between Leaperkim and Inmotion is: the limit is much higher.
 

3 hours ago, smash said:

because rim ... get stuck

Manufacturers have taken different approaches to the "jammed motor" problem: 

• Begode: Motor current will remain at its limit indefinitely, until electrical components fail (which can take more than 20 seconds as I demonstrated previously). 
• Kingsong: After reaching the current limit for just a moment, the limit is reduced to a much lower level.
• Leaperkim: If motor current is sustained at the limit value for one whole second continuously, the motor becomes de-activated.
• Inmotion: Unclear. We suspect a lower current limit is used while stationary, and then a higher limit applies after the motor is above a certain speed.
   

10 hours ago, mrelwood said:

Once you get going, it’s a whole new ball game.

Sad that we don't have a practical way to get quantitative data while moving... but it's easy to test this in a qualitative way, with a pendulum-thrust maneuver. 

For example, I found V11 easier to dip this way, in back-to-back comparison with MSX 84V.

And with my ~170lb riding weight, I was physically unable to make Patton dip. 

  

21 minutes ago, smash said:

Patton ... max current is listed as 680A

680 is marketing nonsense based on the theoretical specification of its FETs. The other components in the system cannot survive it.

Patton limits at 300A. That's a lot! 

[smash]

36 minutes ago, RagingGrandpa said:

Patton limits at 300A. That's a lot! 

Oh interesting, leaperkim's firmware current limit is indeed no lower at a standstill than at speed.

[smash]

3 hours ago, RagingGrandpa said:

Manufacturers have taken different approaches to the "jammed motor" problem: 

• Begode: Motor current will remain at its limit indefinitely, until electrical components fail (which can take more than 20 seconds as I demonstrated previously). 
• Kingsong: After reaching the current limit for just a moment, the limit is reduced to a much lower level.
• Leaperkim: If motor current is sustained at the limit value for one whole second continuously, the motor becomes de-activated.
• Inmotion: Unclear. We suspect a lower current limit is used while stationary, and then a higher limit applies after the motor is above a certain speed.

This is some great info. Which do you think is the better implementation, Kingsong's or Leaperkim's? Leaving out Begode and Inmotion because I find that they are both at an extreme on the performance/durability spectrum.

It'd be interesting to weigh the benefits and drawbacks of going somewhere between begode and LK. Why 1 second? Why indefinite? Seems like an arbitrary choice with the possibility for a more thought-out implementation.

Then again, I imagine that they all drop their limits as soon as you get moving, so being granular probably has limited usefulness. (is their firmware public? maybe you or someone has taken an actual look at the code)

[Rawnei]

5 hours ago, smash said:

This is some great info. Which do you think is the better implementation, Kingsong's or Leaperkim's? Leaving out Begode and Inmotion because I find that they are both at an extreme on the performance/durability spectrum.

It'd be interesting to weigh the benefits and drawbacks of going somewhere between begode and LK. Why 1 second? Why indefinite? Seems like an arbitrary choice with the possibility for a more thought-out implementation.

Then again, I imagine that they all drop their limits as soon as you get moving, so being granular probably has limited usefulness. (is their firmware public? maybe you or someone has taken an actual look at the code)

KingSong's "solution" is just because they had a history of the controllers burning so they limited it, if it wasn't limited and didn't burn that would be best but that's not the reality of it.

I don't know why you think Inmotion is at an extreme of the performance spectrum, they are not.

Patton and Sherman why 1 second? They allow up to 300A, you don't want to sustain that kind of current, if something is demanding continuous high current one can assume that motor might be stuck or other bad scenario and cut the motor as a protective measure, seems like a great solution.

High torque from low RPM is extremely useful when riding technical off-road.

[mrelwood]

Great info, @RagingGrandpa!

19 hours ago, RagingGrandpa said:

For example, I found V11 easier to dip this way, in back-to-back comparison with MSX 84V.

I haven’t tried a significant idling burden on either, but I did feel that the V11 was slightly more capable of slowly crawling up a steep hill with a heavy rider. I was also able to make the magnets skip while braking on the MSX. Both hinting that the mediocre results with both the pull force test and the idling stress test indeed would be under the limited current area.

I think it was WW who videoed a very hard braking on the V13 that started to dip pretty badly once he got down to about walking speeds. And I seem to recall someone having issues with starting from a steep incline on the V13, as it just dipped and didn’t even get going.

 It has seemed to me that the Inmotion’s stationary limits are just a bit too drastic.

 

[smash]

19 hours ago, Rawnei said:

I don't know why you think Inmotion is at an extreme of the performance spectrum, they are not.

They are at an extreme on the basis of every other manufacturer's approach to idle torque response (I'm not talking about when in motion).

19 hours ago, Rawnei said:

Patton and Sherman why 1 second? They allow up to 300A, you don't want to sustain that kind of current, if something is demanding continuous high current one can assume that motor might be stuck or other bad scenario and cut the motor as a protective measure, seems like a great solution.

I get why they do it and why keeping a motor under that stress is bad, but clearly 1 second is an arbitrary measure. I was wondering if someone had more insight into what factors would go into finding an objectively better timeout period (or some other safety measure).

Edited October 3, 2023 by smash

[RagingGrandpa]

Mechanical statics review time...

A facebooker correctly pointed out that if the handle is positioned any way other than horizontally, it will create additional forces on the rope, making the rope force unequal to the tractive force. 

So for my data using vertical handles, tractive force (the thing we really care about) will be slightly less than my measured rope force.
I think it doesn't change the meaning of the results: a relative comparison between EUC's. The ranking of models does not change.
But if we think about other people testing with their own DIY handles, "handle length matters." 

We'll just need to add two steps to the test process:

1. Measure and record the vertical distance from the ground to the axle center (e.g.: the rope height, with a level pulling rope). 
2. Measure and record the vertical distance from the ground to the center of where your hand grips the handle.

I'll add these to the page 1 procedure; and will update the results table soon to show tractive force for my past results. 

Edited October 18, 2023 by RagingGrandpa

[RagingGrandpa]

Table updated for handle length... my handle length "L handle" is 36 inches for the Begode Extreme, which I'll treat as a typical distance for prior results for suspension EUCs. Non-suspension EUC's have lower pedals overall, so those I'll use 34.5". But the difference it makes in the final number is small.

After geometry correction, tractive force comes out around 80% of rope force. 
And since I didn't use handles for the onewheels (because I pushed vertically on their foot pads without using handles), those 3 numbers didn't change. 

I think the only interesting result coming from geometry correction is: third-party claims about motor torque (V14 "850N") will compare more accurately. So V14 could be remarkably strong, in line with Extreme (but still far below Patton).

And that Extreme... seems baffling that it's consistently giving me 35lb less rope force than the nearly-identical-spec Commander Mini. 
Perhaps Extreme will be like the EX30, where firmware updates came later and added more grunt?