Begode EX20S 3600wh: 100V, suspension, 104lb

[Chiway Black]

2 hours ago, TheSlyGiraffEV said:

Did you get a response to do a lift speed test in EUC World? That's what I was asked when I asked about adding the EX20S C30 to the list.

If so, what did you get as your 3 lift speeds?

I can try that tomorrow.

[Chiway Black]

On another note. I cut out today while going up this sidewalk ramp. Was doing maybe 5-10mph with about a 70% charge. I have the C30 motor and I weigh around 260lbs. Is this typical or am I experiencing some sort of fault? This curb is a bit higher in person than what it looks like here.
 

Edit: I'm looking at the logs and it's weird, it doesn't show anything even close to a cut out. Lowest the safety margin got down to was 79 right before you see my speed drop off. No alarms or anything. Any thoughts?

Edited August 30, 2022 by arcyenom

[Chiway Black]

Here's a graph of the data right during the cut out. I've highlighted the portion right before so  you can see the data. 

[Chriull]

30 minutes ago, arcyenom said:

Here's a graph of the data right during the cut out. I've highlighted the portion right before so  you can see the data. 

One would need to make a graph of motor current vs speed to see if it could have been an overlean 

 

[Chiway Black]

10 hours ago, arcyenom said:

I can try that tomorrow.

Over 4 free spin tests I got; 53.3mph, 51.6mph, 57.1.mph, and 52.3 mph. All at 100% battery.

[Chiway Black]

53 minutes ago, Chriull said:

One would need to make a graph of motor current vs speed to see if it could have been an overlean 

 

I just sent you the CSV in case that helps. The more I look at it, the more I think it was an overlean. Looks like my speed and current draw ramped up as I got to that sidewalk ramp. Had I maintained speed and/or hit it going a bit faster from the start it would have likely been alright. 

[EUC Sharkman]

11 hours ago, arcyenom said:

On another note. I cut out today while going up this sidewalk ramp. Was doing maybe 5-10mph with about a 70% charge. I have the C30 motor and I weigh around 260lbs. Is this typical or am I experiencing some sort of fault? This curb is a bit higher in person than what it looks like here.
 

Edit: I'm looking at the logs and it's weird, it doesn't show anything even close to a cut out. Lowest the safety margin got down to was 79 right before you see my speed drop off. No alarms or anything. Any thoughts?

Are you using the stock pads, or pads like Clark’s or Grizzlas? I was on a ride this past weekend and was using my old Clark pads for the first time on this wheel. Previously I just used Stock pads. I eventually found the Clark pads and my positioning of them to be too aggressive because I was getting that crunchy motor behavior right before an over lean for very basic moves like a curb drop, or accelerating off the line. I’ve since switched back to stock until I can get a more suitable pad setup that won’t cause me to accidentally over lean.

[EUC Sharkman]

51 minutes ago, arcyenom said:

Over 4 free spin tests I got; 53.3mph, 51.6mph, 57.1.mph, and 52.3 mph. All at 100% battery.

This is pretty consistent with what I got too. It’s strange though because I’ve heard of other folks getting their speeds consistently in the mid 60’s.

[Chiway Black]

40 minutes ago, TheSlyGiraffEV said:

Are you using the stock pads, or pads like Clark’s or Grizzlas? I was on a ride this past weekend and was using my old Clark pads for the first time on this wheel. Previously I just used Stock pads. I eventually found the Clark pads and my positioning of them to be too aggressive because I was getting that crunchy motor behavior right before an over lean for very basic moves like a curb drop, or accelerating off the line. I’ve since switched back to stock until I can get a more suitable pad setup that won’t cause me to accidentally over lean.

I have the stock pads. I'm getting the exact same thing. I've almost cut out twice coming off the line too hard.

38 minutes ago, TheSlyGiraffEV said:

This is pretty consistent with what I got too. It’s strange though because I’ve heard of other folks getting their speeds consistently in the mid 60’s.

I have the shinko knobby on. Could be a factor. Still rubs a little.

[EUC Sharkman]

Yeah, I usually can't go too crazy at the start since it's a heavy wheel with a C30 motor. I don't normally lean into the pads until after hitting 15-20 mph. I have my pads pushed all the way forward to prevent any accidental over torque, use my feet/weight to get going, and use the pads.

[Chriull]

18 hours ago, arcyenom said:

Here's a graph of the data right during the cut out. I've highlighted the portion right before so  you can see the data. 

In your graph (unfortionately) the current column is taken from the log - this is the calculated/estimated battery current value, which is of no interest in your case. The real from the begode wheel reported number is "current_phase" - the motor phase current. Showing this value in the diagram reveals the following:

You hit about 200A! So the internal short circuit/current limiting had to shut off or the mosfets, wiring and/or pcb would have gone...

According to your graph the maximum calculated battery current is "just" ~85A.

The (phase) current over speed diagram would not have been necessary for this - but here one sees nice how you "hit" two times this 200A limit. Once at ~12 km/h and once at ~17 km/h...

FYI the total log as Current over Speed Diagram:

(Edit: graph taken out since it's now in the next post with the guessed limits)

If you take some logs of lifting the wheel and let it spin until it cut offs you can get some upper limit speed wise and maybe can already "guestimate" the limit line from there on...

Up to the horizintal 200A limit line you already encountered...

Edited August 31, 2022 by Chriull

[Chriull]

BTW - tries to guess/calculate some limts to your EX20S graph. From the smartwheel sales site i have the info that the free spin speed (lift cut off speed) is 82 km/h. I hope this is right for the EX20S with full batteries? If not the diagram has to be redone...

The other unknown is the coil resistance - so i made an area covering the range from 0,15 to 0,3 Ohm... Should be somewhere in this area?

Battery resistance was taken with 60 mOhm (24s8p config with 20mOhm single Cell resistance)

Battery started out with about 75% charge (~95V) and was at the end at about 93,5V (~71% charge)

With this riding just with empty batteries and high (guessed) coil resistance overleans would have occured (lower yellow limit line crossing the blue driving log - Phase current vs Speed).

If (coil resistance is lower and/or) battery charge state is higher there is enough safety margin for this kind of riding.

[GoGeorgeGo]

On 8/30/2022 at 2:02 AM, arcyenom said:

On another note. I cut out today while going up this sidewalk ramp. Was doing maybe 5-10mph with about a 70% charge. I have the C30 motor and I weigh around 260lbs. Is this typical or am I experiencing some sort of fault? This curb is a bit higher in person than what it looks like here.
 

Edit: I'm looking at the logs and it's weird, it doesn't show anything even close to a cut out. Lowest the safety margin got down to was 79 right before you see my speed drop off. No alarms or anything. Any thoughts?

so far in 2500 miles the only time i almost overpowered the ex20hs was actually about 2 weeks ago on a take off. i pulled up to a stop light and happened to stop inside of a recessed sewer cap. with tire against the lip i whent to take off kinda aggressively and it skipped a magnet on me . luckily there wasnt anyone behind me as i had to dismount awkwardly to avoid falling 

[supercurio]

4 hours ago, Chriull said:

BTW - tries to guess/calculate some limts to your EX20S graph. From the smartwheel sales site i have the info that the free spin speed (lift cut off speed) is 82 km/h. I hope this is right for the EX20S with full batteries? If not the diagram has to be redone...

The other unknown is the coil resistance - so i made an area covering the range from 0,15 to 0,3 Ohm... Should be somewhere in this area?

Battery resistance was taken with 60 mOhm (24s8p config with 20mOhm single Cell resistance)

Battery started out with about 75% charge (~95V) and was at the end at about 93,5V (~71% charge)

With this riding just with empty batteries and high (guessed) coil resistance overleans would have occured (lower yellow limit line crossing the blue driving log - Phase current vs Speed).

If (coil resistance is lower and/or) battery charge state is higher there is enough safety margin for this kind of riding.

I like what you're doing here @Chriull, and will definitely come back to your post once it's time to implement more alarms, leveraging phase current in EUC Alarm app 🙏

[Chiway Black]

22 hours ago, arcyenom said:

Over 4 free spin tests I got; 53.3mph, 51.6mph, 57.1.mph, and 52.3 mph. All at 100% battery.

@Chriull here's the free spin cut off for my wheel. 

Either way that analysis is amazing. Really helps put the situation into context. Going to spend some time studying the graph and adjusting my ride style accordingly. Thank you!

 

Any advice for EUC world alarms I could put into place given this data?

Edited August 31, 2022 by arcyenom

[Chriull]

28 minutes ago, arcyenom said:

@Chriull here's the free spin cut off for my wheel. 

So thats some 8x to 90km/h. Seems the lower point of the limit lines could be shifted slighty to the right.

28 minutes ago, arcyenom said:

Either way that analysis is amazing. Really helps put the situation into context. Going to spend some time studying the graph and adjusting my ride style accordingly. Thank you!

 

Any advice for EUC world alarms I could put into place given this data?

In regard to this 200A current limit no alarm can help you. This spikes happen so fast that every alarm by an external app would trigger after the cut off. Internal alarms would happen too close to the cut off so there would be no chance to react.

Any duration within this near 200A range within reactian time like _some_ tenth of seconds would fry the wheel.

So these incidents caused by the 200A limit you have to anticipate by your experience.

Usefull euc world alarms for begode wheels is some _phase_ current alarm to prevent mosfet/wire damage. Used to be in the 80-100A range. This will trigger during riding, but should not too often or continously. With the newer begodes this limit should be higher - more in the 120A region maybe? Or even higher looking at your log?

And afair euc world has some smoothing for current alarms by now, too?

I could not really think of any usefull alarm with the calculated battery current.

The pwm alarms are nice, but as they are external and for begode wheels additionally calculated not too fast and not too accurate - so not usefull for higher accelerations/burdens at higher speeds as the alarm would be triggered too late.

For avoiding the limits @Freestyler's modified firmwares (tiltback triggered by some pwm % threshold) seems to be perfect:

 

Edited August 31, 2022 by Chriull

[Chiway Black]

@Chriull thanks again. Really appreciate your insight.

[supercurio]

unfortunately @

4 hours ago, Chriull said:

Usefull euc world alarms for begode wheels is some _phase_ current alarm to prevent mosfet/wire damage. Used to be in the 80-100A range. This will trigger during riding, but should not too often or continously. With the newer begodes this limit should be higher - more in the 120A region maybe? Or even higher looking at your log?

And afair euc world has some smoothing for current alarms by now, too?

I could not really think of any usefull alarm with the calculated battery current.

Spot on comments in your whole post.

Unfortunately EUC World doesn't support phase current alarms anymore, only estimated battery current or estimated safety margin - neither are super helpful at lower speeds.

[Chriull]

16 minutes ago, supercurio said:

Unfortunately EUC World doesn't support phase current alarms anymore

Oh. That's a pitty

Gotway reporting phase current and apps having an alarm must have saved many wheels over time.

[supercurio]

Yes that's why I want to re-introduce it in my own apps.

With reasonable defaults phase current alarms presets for each wheel, I think it might help avoid a few crashes, burned board or over-leans when climbing steep inclines or accelerating hard.

Edited August 31, 2022 by supercurio

[Chriull]

23 minutes ago, supercurio said:

Yes that's why I want to re-introduce it in my own apps.

Try to use for "smoothing" the root mean square as this is the relevant value for power dissipation!

[Freestyler]

On 8/31/2022 at 12:51 PM, Chriull said:

BTW - tries to guess/calculate some limts to your EX20S graph. From the smartwheel sales site i have the info that the free spin speed (lift cut off speed) is 82 km/h. I hope this is right for the EX20S with full batteries? If not the diagram has to be redone...

The other unknown is the coil resistance - so i made an area covering the range from 0,15 to 0,3 Ohm... Should be somewhere in this area?

Battery resistance was taken with 60 mOhm (24s8p config with 20mOhm single Cell resistance)

Battery started out with about 75% charge (~95V) and was at the end at about 93,5V (~71% charge)

With this riding just with empty batteries and high (guessed) coil resistance overleans would have occured (lower yellow limit line crossing the blue driving log - Phase current vs Speed).

If (coil resistance is lower and/or) battery charge state is higher there is enough safety margin for this kind of riding.

Excellent stuff. I pinged you a while back to give us an approximation formula in this thread: 

 

 

Please write a formula in layman terms that I can work with, because I have trouble wrapping my head around that stuff. 

Got some good news on this front: Master pro firmware returns a SetOverCurrent boolean flag in extended packets.

It is set by some intense calculations, but I'm not sure if it alerts based on that yet.

Edited September 1, 2022 by Freestyler

[Chiway Black]

Welp, my trolley handle broke today. One of the little nubs broke awhile ago but the second one is now a goner too. Trying to figure out how to keep the trolley handle down given the spring for a temporary fix.  Alien Rides has already ordered spare parts for me. 

Edit: Took the spring out so at the very least the handle isn't popping up on me while riding. There needs to be a more robust fix put in place for these small pieces of metal that are supposed to hold the trolley handle on, though.

Edited September 1, 2022 by arcyenom

[GoGeorgeGo]

i gotta say, after getting some information about the size of some of the new wheels. I am really glad i got the ex20

its the perfect size imo as far as form factor is concerned. these new wheels, the v13, the master pro/master x, they are going to be massive. super tall.

if your a sit rider for the majority of your riding i think you will like the huge height on these new wheels. but if you stand, you may not like how these wheels handle and ride.

granted this is just a feeling i have as obviously i have not stepped on these new wheels yet. but my firsr impressions are that the ex20s is going to be far from obsolete imo

[meepmeepmayer]

Haha, the EX20S is the small and light wheel now