Another Wheel (ACM2) Succumbs To Overheat-Hill

[Marty Backe]

I took the Z10 to Whittier Hills so that @Jrkline "Wheel Whisperer" could see and take it for a spin. The Sun would be setting in about an hour, but the temperatures were still in high 80's due to the heat-wave that Southern California has been stuck in.

We headed into the hills, me on the Z10 and Jeff on his ACM2, which he had recently modded. Two vents were added to increase air flow inside the wheel, and Jeff really wanted to test the vent effectiveness on Overheat-Hill.

The introductory hill into my mountain proving grounds is a good test to start with. Jeff shot up the hill in one run and his ACM barely got into the 50's. My Z10 overheated a couple of times (really looking forward to the production wheel). So Jeff was really stoked with how well his modded ACM2 was performing. This should have been seen as a warning sign not to get too cocky.

Next we stopped at a super steep hill that only one wheel is capable of climbing, the MCM5. Jeff wanted to try anyway, so I humored him and stood by as he attempted the climb. He had to abort the run when his Pebble watch started buzzing, telling him that his ACM2 was drawing 140-amps.

Next stop, Overheat-Hill. I wasn't even going to attempt this with the Z10 because it wouldn't make it and the ride up the hill would be very slow and long.  So I took the back road to the summit as Jeff proceeded to the bottom. As I was stationed at the top I could eventually see Jeff making his way up the hill, proceeding nicely if not super fast.

As he as approaching the final 1/4 distance to the top he face-planted. I shook my head, knowing this was not a good sign. Gotway wheels do no cutout in these conditions unless there is a hardware failure. The last time I saw Jeff face-plant it was on this identical hill, but it was on his KS16B - a fuse blew that time. But I knew this time that it was either melted wires and/or blown MOSFETs.

I clambered down the hill to meet Jett, and the wheel was opened. We eventually discovered at least one MOSFET that was now missing a lead. Later Jeff mentioned to me that he had seen a bit of smoke exiting from his ACM2 vents. And by the way, probably at least 15-minutes after the wheel had collapsed and the wheel opened, I felt the motor connectors and they were still HOT.

KingSong may blow a fuse, and Inmotion and Ninebot shut down, but Gotway still remains the champ at blowing up MOSFETs. And this is the new and improved ACM2 control board. It's a mystery why they can't hire engineers that can design a board that will not destroy itself in these situations.

Jeff had to lug his 50-pound wheel (no trolley) probably a mile up and down the mountain. And then we discovered that this entrance to the park closes at 6pm. Totally surrounded by 8-foot tall iron fences and a locked gate. We had to call a ranger dispatch, talk to a ranger, and wait almost an hour for him to show up. He ended up being a really nice guy and decided not to fine us for being in the park 3-hours after it closed with illegal devices (the usual 'no motor vehicles' rule). He was good natured and eventually told me that he was a unicyclist. I gave me my EUC card so he could see what these are all about.

So Jeff is working on acquiring a new control board from Jason, and apparently a Z10 too 

[winter]

 

[Thai-lad]

Has the MCM5 ever been tested on that hill?  If not, given Gotway's tendency to fry rather than gracefully shut down, will you dare try?

[ED209]

50 minutes ago, Marty Backe said:

Jeff had to lug his 50-pound wheel (no trolley) probably a mile up and down the mountain. And then we discovered that this entrance to the park closes at 6pm. Totally surrounded by 8-foot tall iron fences and a locked gate. We had to call a ranger dispatch, talk to a ranger, and wait almost an hour for him to show up

Poor Jeff. After 2 faceplants he needs to go easy with his wheels, glad to hear he wasn't injured,  also good to see that he is still keen after this recent experience, others would be put off. What an adventure you guys had. ?

[trya]

oh, well, here goes "if I had only one wheel for trails and hills" ACM2 selection  Would you correct it to MCM5 now, Marty? Just kidding... I know you wouldn't change your favorites that easily

[Chriull]

1 hour ago, Marty Backe said:

KingSong may blow a fuse, and Inmotion and Ninebot shut down, but Gotway still remains the champ at blowing up MOSFETs. And this is the new and improved ACM2 control board. It's a mystery why they can't hire engineers that can design a board that will not destroy itself in these situations

Imho thats mainly from using some temperature sensor too far away from the mosfets - they are blown before the alarm can ring. The other "extreme" is the v10 where the sensor sits on the heatsink beside the mosfets - it warns quite immedeately! So they have no mosfet blow up prob but overheat warning prob for heavier riders.

There is still quite some way to go until the wherls are designed well enough to get rid of the power dissipated by the mosfets...

[Marty Backe]

24 minutes ago, Chriull said:

Imho thats mainly from using some temperature sensor too far away from the mosfets - they are blown before the alarm can ring. The other "extreme" is the v10 where the sensor sits on the heatsink beside the mosfets - it warns quite immedeately! So they have no mosfet blow up prob but overheat warning prob for heavier riders.

There is still quite some way to go until the wherls are designed well enough to get rid of the power dissipated by the mosfets...

However, I have no fear that the Z10 will destroy itself. And my KingSong won't destroy itself (but I do carry spare fuses with me).

I think it's poor engineering on Gotway's part. Same with Gotway chasing the higher-voltages. After my experience with the 58-volt Z10 which, except for steep hills, behaves like my other performance wheels, I think the higher voltage wheels is a cheap and fast way to better performance. Ninebot demonstrates that better engineering can arrive at the same solution.

Of course I'll have to eat some of my words if the production Z10 doesn't have 1/3'rd more torque as promised.

[Marty Backe]

48 minutes ago, trya said:

oh, well, here goes "if I had only one wheel for trails and hills" ACM2 selection  Would you correct it to MCM5 now, Marty? Just kidding... I know you wouldn't change your favorites that easily

This is why I'm now very hesitant to push my Gotway wheels to the extreme. I've learned how to ride them - I can sense the amount of strain that I'm putting on the wheel and will abandon the effort after a few moments if necessary.

The one Gotway wheel that I feel is invulnerable (only based on my personal experience) is the MCM5. Yet for all but the craziest of hills, it's my ACM2 

We must also keep in mind that Jeff has 30 to 40 pounds on me 

56 minutes ago, Edddeus said:

Poor Jeff. After 2 faceplants he needs to go easy with his wheels, glad to hear he wasn't injured,  also good to see that he is still keen after this recent experience, others would be put off. What an adventure you guys had. ?

Jeff and I have had many good and bad adventures with our wheels. It's a blast.

[Marty Backe]

1 hour ago, Thai-lad said:

Has the MCM5 ever been tested on that hill?  If not, given Gotway's tendency to fry rather than gracefully shut down, will you dare try?

Of course. It's in my MCM5 thread. There's a video about it. The MCM5 screamed up the same hill and barely got warm. I crowned it the king of all mountain wheels. No other wheel can climb like the MCM5.

[Thai-lad]

36 minutes ago, Marty Backe said:

Of course. It's in my MCM5 thread. There's a video about it. The MCM5 screamed up the same hill and barely got warm. I crowned it the king of all mountain wheels. No other wheel can climb like the MCM5.

OK, I saw that vid earlier on YouTube, wasn't sure it was the same hill ☺.  Guess I might have to seriously consider getting an MCM5 instead of a KS14S now.

[Mark Lee]

The THUMP that I felt from the OP, was it from Jeff's face plant or face plant of ACM2 sales?  

[maltocs]

This is one of those moments where I'm glad I have the self-preserving V10F. I may overheat all day long, but (so far) I've only had to restart and not walk it back (knock on wood). 

[Marty Backe]

21 minutes ago, Thai-lad said:

OK, I saw that vid earlier on YouTube, wasn't sure it was the same hill ☺.  Guess I might have to seriously consider getting an MCM5 instead of a KS14S now.

I own the KS14S too. I thought the 14S used to be the best 14-inch wheel being made. But with the introduction of the MCM5 I can no longer recommend the KS14S if you're looking for a super-fast and powerful 14-inch wheel. The KS14S is still a great wheel, but it pales next to the MCM5.

[Marty Backe]

21 minutes ago, Mark Lee said:

The THUMP that I felt from the OP, was it from Jeff's face plant or face plant of ACM2 sales?  

I want to report these occurrences but I worry that people will than say the ACM2 is worthless. Jeff's a big guy. If you were standing on the top of that hill with me and looking far down the slope and saw the ACM2 climbing, you'd be impressed as hell that a wheel can make it.

This is an extreme hill. The only time wheels are exposed to something like this is when they are brought to this hill. 99.9% of people will never ride their wheels like this.

[Marty Backe]

18 minutes ago, maltocs said:

This is one of those moments where I'm glad I have the self-preserving V10F. I may overheat all day long, but (so far) I've only had to restart and not walk it back (knock on wood). 

Have you compared Overheat-Hill to your hills yet?

[Hunka Hunka Burning Love]

Does the ACM2 have those little cooling fans?  Have you tested the Tesla’s climbing abilities?  I do remember a climbing test video, but I wasn’t sure if you tackled the same hills.  Is the control board in the ACM2 the same as the MSuperX?

[Mark Lee]

1 minute ago, Marty Backe said:

I want to report these occurrences but I worry that people will than say the ACM2 is worthless. Jeff's a big guy. If you were standing on the top of that hill with me and looking far down the slope and saw the ACM2 climbing, you'd be impressed as hell that a wheel can make it.

This is an extreme hill. The only time wheels are exposed to something like this is when they are brought to this hill. 99.9% of people will never ride their wheels like this.

I love my ACM2 and would like to see more people enjoy the ride it gives.  But when it blows main board ( under any circumstances ) I think it will scare people away and I can understand why.  Still it is great wheel as long as people understand the limits, that's why I thank Jeff for testing its envelope.  He's more man than I.  

[Marty Backe]

Just now, Mark Lee said:

I love my ACM2 and would like to see more people enjoy the ride it gives.  But when it blows main board ( under any circumstances ) I think it will scare people away and I can understand why.  Still it is great wheel as long as people understand the limits, that's why I thank Jeff for testing its envelope.  He's more man than I.  

BTW, he had his Pebble watch configured for 140-amps. I told him I think that was way to high. Mine is set to 90-amps. I think if he had used a lower alarm setting he would have been getting continuous buzzing and would have stopped before it was too late.

[Marty Backe]

4 minutes ago, Hunka Hunka Burning Love said:

Does the ACM2 have those little cooling fans?  Have you tested the Tesla’s climbing abilities?  I do remember a climbing test video, but I wasn’t sure if you tackled the same hills.

Yes, the ACM2 has the single fan. And Jeff had installed two vents. The wheel was running relatively cool during this run (50's I think).

Yes, I've tested the Tesla, but not on Overheat Hill for somewhat obvious reasons. 

[Mark Lee]

1 minute ago, Marty Backe said:

BTW, he had his Pebble watch configured for 140-amps. I told him I think that was way to high. Mine is set to 90-amps. I think if he had used a lower alarm setting he would have been getting continuous buzzing and would have stopped before it was too late.

I too use Pebble watch with my wheels Gotway and Kingsong.  I too have it set at 90 amps as you've suggested and it buzzes at times I wouldn't think it would.  I think Pebble watch and WheelLog is a must if you are intent on pushing your wheels to its limits.  

[Hunka Hunka Burning Love]

It’s interesting to see that the MCM5 with it’s small side mounted control board with no fans can make it without issue while other wheels can’t.  After seeing some tear down videos, it doesn’t seem to have anything special about it.  I wonder why that particular wheel does so well.

[Marty Backe]

11 minutes ago, Hunka Hunka Burning Love said:

It’s interesting to see that the MCM5 with it’s small side mounted control board with no fans can make it without issue while other wheels can’t.  After seeing some tear down videos, it doesn’t seem to have anything special about it.  I wonder why that particular wheel does so well.

I can assure you that the MCM5 has a fan. I hear the little guy running all the time.

It takes less power (watts) to rotate a 14-inch wheel compared to the bigger wheels. But why the more powerful wheel doesn't generate more heat is an interesting question.

[Marty Backe]

19 minutes ago, Mark Lee said:

I too use Pebble watch with my wheels Gotway and Kingsong.  I too have it set at 90 amps as you've suggested and it buzzes at times I wouldn't think it would.  I think Pebble watch and WheelLog is a must if you are intent on pushing your wheels to its limits.  

I agree.

You'll probably never encounter a truly stressful condition, but if your watch ever does continuously buzz for more than a handful of seconds, stop whatever you're doing.

[maltocs]

47 minutes ago, Marty Backe said:

Have you compared Overheat-Hill to your hills yet?

Your overheat hill is definitely a little steeper than my long test hill, however, the Griffith Concrete Hill that @Stan Onymous rides on puts us both to shame.

In order

My Ernest Debs Hill - 259ft elevation over 0.5 miles,

Whittier Overheat Hill - 331ft over 0.4 miles

Griffith Concrete Hill - 308ft over 0.3 miles

However, my super steep hill I reference once in a while is about the same or steeper than the griffith concrete hill but not nearly as long. 

[Marty Backe]

29 minutes ago, maltocs said:

Your overheat hill is definitely a little steeper than my long test hill, however, the Griffith Concrete Hill that @Stan Onymous rides on puts us both to shame.

In order

My Ernest Debs Hill - 259ft elevation over 0.5 miles,

Whittier Overheat Hill - 331ft over 0.4 miles

Griffith Concrete Hill - 308ft over 0.3 miles

However, my super steep hill I reference once in a while is about the same or steeper than the griffith concrete hill but not nearly as long. 

Nice graphics!

There is one other attribute that can affect the stress on the wheels; trail condition. Overheat-Hill is not an easy slope to climb, requiring a lot of maneuvering. Any paved or graded path will be much easier on the wheel.