Gotway ACM 1600 Autopsy and Mods

[Rehab1]

4 hours ago, Hunka Hunka Burning Love said:

 

I was curious about the latching specification so I looked up outrunner magnet orientation:

With the photos you need to zoom into the tops of the chips to see the ID numbers... likely that larger square chip with the pins on all four sides...

 

Interesting food for thought! Thanks! Certainly a learn curve! 

I love experimenting but it would have been nice if GW had responded to my inquiry about the hall sensor used in the motor beyond their boiler plate adage "please direct your questions to the seller". 

4 hours ago, Hunka Hunka Burning Love said:

I helped assemble one of these which was fun.  There are so many components to solder and put together.  We didn't have the remote though...

You are the first person I have communicated with that built the Hero! I want to purchase that kit in the worst way!

 

3 hours ago, electric_vehicle_lover said:

Passing a magnet in front of the sensors will make them change their output signals - them you can measure that signal. All this just for you to verify that they are working. If they are working and you connect them to the board, as the originals were, IMO there is high probability that EUC will work again perfectly.

That sounds like a prudent validation plan! Thanks!

3 hours ago, electric_vehicle_lover said:

That pictures don't show the microcontroller reference. The boards like MicroWorks and others chinese alike, probably also GotWay, (including the hoverboards) use the STM32F103C8T6. Would be great if you could verify in your board.

I will study the board closer on Monday and look for any identifiable references.

[Rehab1]

On 4/1/2017 at 8:39 PM, Rehab1 said:

On 4/1/2017 at 5:29 PM, electric_vehicle_lover said:

That pictures don't show the microcontroller reference. The boards like MicroWorks and others chinese alike, probably also GotWay, (including the hoverboards) use the STM32F103C8T6. Would be great if you could verify in your board.

 

@electric_vehicle_loverThe micro controller only has the reference 'Gotway Unicycle' printed on the board and this tag. I wish there was more!

After soldering 3 wires onto one of the compromised ACM hall sensors I ended up with a microscopic bridge between 2 of the legs. A continuity test confirmed my findings. The sensor is toast.

I have one more original hall sensor that I will try the same process on tomorrow. If successful I will be able to run tests on both old and new hall sensors to make sure the electromagnetic switching characteristics are identical.

[electric_vehicle_lover]

1 hour ago, Rehab1 said:

@electric_vehicle_loverThe micro controller only has the reference 'Gotway Unicycle' printed on the board and this tag. I wish there was more!

Hmmm, I am not sure you did understand what is the microcontroller. It is the largest chip on the board, near the 8.000 MHz Crystal on the board, like on this picture (please note that was removed on this picture):

 

[Hunka Hunka Burning Love]

I tried zooming into your photo @Rehab1.   Right is likely the microcontroller and the left chip the gyro?  Can you get a better photo with maybe some chalk smudgings?

If you have some copper braid solder wick you can use that to remove the solder bridge and try again or try an Xacto knife or scapel to cut through the solder bridge.  Kynar wire also is helpful for these small jobs.

[Rehab1]

 

11 hours ago, electric_vehicle_lover said:

Hmmm, I am not sure you did understand what is the microcontroller. It is the largest chip on the board, near the 8.000 MHz Crystal on the board, like on this picture (please note that was removed on this picture):

 

11 hours ago, Hunka Hunka Burning Love said:

I tried zooming into your photo @Rehab1.   Right is likely the microcontroller and the left chip the gyro?  Can you get a better photo with maybe some chalk smudgings?

 

I have climbed the mountain and now see the light! It reads 'Hunkahunka'! No wonder GW is having all of these problems!  

 Here is a closeup.

 

[electric_vehicle_lover]

So that's the same of MicroWorks 30B4 boards!! So MicroWorks have boards with 6 mosfets and 12 mosfets, with the same microcontroller. The firmware may not be very different because depends on the microcontroller (that is the same) and the circuit board. As far as I can see, the board is almost similar for the motor currents and battery voltage readings. Also sensors to read temperature seems the same (no dedicated sensor, just the internal temperature sensor inside de MPU IC).

Looks like GotWay and other alike use the same level of technology. The knowledge I am being sharing seems to apply to most EUCs, even for the famous brands like GotWay. I think is really great that we now have such knowledge and (almost) the technology in OpenSource - I mean, the electronic board schematics, the firmware and the mobile apps.

Your message of this GotWay unicycle is great!! We now have even much more knowledge!!! I wish we could write a good technical documentation for repair, mods or DIY build of EUCs.

[meepmeepmayer]

I've lost track of what's going on with your wheel. Are you confident you'll get it working (again, technically)??

The disassemble and new wiring and extras was a bit scary, but ultimately not that bad. But when suddenly some brittle specific sensor wiring breaks... ugh *heart sinks*. But looks like you are on schedule to fixing that! In the end, you'll have the best ACM on the planet (or maybe second best if you consider the 67V but 2040 Wh FrankenACM).

Also I'm sure a lot of people may never post here, but find great assistance in your photos and descriptions on how you did the various things

[Rehab1]

2 hours ago, electric_vehicle_lover said:

So that's the same of MicroWorks 30B4 boards!! So MicroWorks have boards with 6 mosfets and 12 mosfets, with the same microcontroller. The firmware may not be very different because depends on the microcontroller (that is the same) and the circuit board. As far as I can see, the board is almost similar for the motor currents and battery voltage readings. Also sensors to read temperature seems the same (no dedicated sensor, just the internal temperature sensor inside de MPU IC).

Looks like GotWay and other alike use the same level of technology. The knowledge I am being sharing seems to apply to most EUCs, even for the famous brands like GotWay. I think is really great that we now have such knowledge and (almost) the technology in OpenSource - I mean, the electronic board schematics, the firmware and the mobile apps.

Your message of this GotWay unicycle is great!! We now have even much more knowledge!!! I wish we could write a good technical documentation for repair, mods or DIY build of EUCs.

I am learning a great deal reading your f/U posts. Many thanks! We may eventually discover many of the parts are interchangeable with other manufacturers. I contacted a number of manufacturers on Alibaba that offered 60V EUC motors with hall sensors but they were only 350 watts max. I was interested to see where Gotway purchased the motors being they have not responded favorably to my request for parts. The Aliexpress GW seller unfortunately is non communicative on the subject. 

2 hours ago, meepmeepmayer said:

I've lost track of what's going on with your wheel. Are you confident you'll get it working (again, technically)??

The disassemble and new wiring and extras was a bit scary, but ultimately not that bad. But when suddenly some brittle specific sensor wiring breaks... ugh *heart sinks*. But looks like you are on schedule to fixing that! In the end, you'll have the best ACM on the planet (or maybe second best if you consider the 67V but 2040 Wh FrankenACM).

Also I'm sure a lot of people may never post here, but find great assistance in your photos and descriptions on how you did the various things

Making slow progress as parts and various electrical components arrive. Working on a number of fronts:

)1 Large Motor wiring- 75% compete. Still need to drill holes in PCB and solder wires.

2) Testing old hall sensor characteristics against new hall sensors (arrive tomorrow). I also ordered a UNO R3 micro controller board to hook up the hall sensors properly for testing. 20% complete

2) Cooling System- 25 % complete. Waiting on voltage regulator and  on/off switch (arrives Friday) to step down battery voltage to 12 volt to power the cooling fan. I still need to cut out side panel for fan exhaust and the air intake

3) Temperature Data Logger- 75% compete. Just requires fastening and further testing. 

4) RAM INDUCTION........%complete

I was able to add wires to the one remaining hall sensor. So fragile. No signs of solder bridging this time. The ohm reading is still measuring 5 which was the initial reading before the sensor were removed. Hopefully the heat from soldering did not destroy any of the internal components. I surrounded the wires on the sensor with silicone so they would not come off. 

 

Yes it will be back together soon. I expect within 2 weeks if all goes well.

 

[meepmeepmayer]

Wow, you are a more courageous man than I am. Thanks for the update. Crazy how this has balooned *cough*

Do you know any sensors with the right characteristics will work, or is that more of a hope?

[Rehab1]

12 minutes ago, meepmeepmayer said:

Wow, you are a more courageous man than I am. Thanks for the update. Crazy how this has balooned *cough*

Do you know any sensors with the right characteristics will work, or is that more of a hope?

Courageous... you mean ---->Big Dummy?

A bipolar latched version is what I have determined through research. If I can test the 2 versions side by side I should be able to obtain some quantifiable data to determine if their electromagnetical characteristics match. The sensors are cheap so if the new ones don't perform as expected I will move on to another type.   Once done with all of the mods I'll run an advertisement on the forum for a test pilot!

[Hunka Hunka Burning Love]

https://getyarn.io/yarn-clip/embed/e8c41a95-d900-40d7-b9a1-58f714798df2

[andress]

I did change my hall sensors. I fried the originals so there was no way to compare but I pretty much bought the first bipolar latching hall sensors I could get. Till today it works witout any issues.

 

[SuperSport]

38 minutes ago, andress said:

I did change my hall sensors. I fried the originals so there was no way to compare but I pretty much bought the first bipolar latching hall sensors I could get. Till today it works witout any issues.

And, you have proper heat shrink tubing in place after the replacement.  Nice Job!

[Rehab1]

10 hours ago, andress said:

I did change my hall sensors. I fried the originals so there was no way to compare but I pretty much bought the first bipolar latching hall sensors I could get. Till today it works witout any issues.

That is great news! My new hall sensors arrived today. I still want to compare the characteristics between the two so I have an hall sensor experiment board I am putting the final touches on. If the sensors are compatible that will be one big leap towards finishing this project. 

[Jrkline "Wheel Whisperer"]

On 4/5/2017 at 7:01 AM, meepmeepmayer said:

 In the end, you'll have the best ACM on the planet (or maybe second best if you consider the 67V but 2040 Wh FrankenACM).

"Best" is subjective.I do not consider the "world famous" ACM2040 to be the "best", just the one with the most wh capacity.That is of course excluding the boys from across the pond who like to stack batteries outside atop the wheel in their videos. If I thought that there was a "best" wheel;I wouldn't currently have 10 of them in the inventory.

[meepmeepmayer]

This is offtopic

9 hours ago, jrkline said:

"Best" is subjective.I do not consider the "world famous" ACM2040 to be the "best", just the one with the most wh capacity.That is of course excluding the boys from across the pond who like to stack batteries outside atop the wheel in their videos. If I thought that there was a "best" wheel;I wouldn't currently have 10 of them in the inventory.

I think battery capacity is the #1 thing that makes or breaks a wheel, so I consider your ACM the best overall in real world usefulness. Sure you can improve the wiring and add whatever comfort features (better lights or so) on any wheel, but hard to beat huge batteries.

I've already had the fantasy to add some kind of hard "bag" (maybe made with fiberglass?) on top of the wheel for optionally storing stuff, but if you combine that with more batteries that's even better - you could (at least space-wise, let's not talk about money) easily add two 800Wh battery packs in there and have an ACM 2900 or 3200 (starting with the 1300 or 1600 versions).

If you have links to these videos of the boys stacking batteries atop their wheels, I'd be very interested Once my wheel is back in working order, not sure how long I can hold still before wanting to modify something (already experimented with a ton of cushioning), and dreaming is free (unlike batteries).

[thefork]

8 minutes ago, meepmeepmayer said:

If you have links to these videos of the boys stacking batteries atop their wheels, I'd be very interested

One such person is Ian at Speedy Feet: 

 

[meepmeepmayer]

Thanks, I've already seen these. I'm more interested in the casings if there are any. Not sure how many shell modifications there are, but if you know some...

[Jrkline "Wheel Whisperer"]

2 hours ago, meepmeepmayer said:

If you have links to these videos of the boys stacking batteries atop their wheels, I'd be very intereste

 

2 hours ago, thefork said:

One such person is Ian at Speedy Feet: 

This is what I was referring to when I mention the "boys across the pond".

 

2 hours ago, meepmeepmayer said:

I think battery capacity is the #1 thing that makes or breaks a wheel, so I consider your ACM the best overall in real world usefulness. Sure you can improve the wiring and add whatever comfort features (better lights or so) on any wheel, but hard to beat huge batteries.

Thankyou. Adding increased range to my various and sundry wheels has kinda become "my thang".

[meepmeepmayer]

From where you are, there are two ponds, so I wasn't sure if it's something I've not heard about. Crazy Chinese mods or so you found on your China visit I agree with you, even if it's not really needed much, big batteries are just cool somehow.

Expanding batteries should be relatively simple, right? Are the inter-battery connections a problem (I read here somewhere that, optimally, all batteries should be connected to each other for balancing and safety)? Can it be done by only making a hole (or two) in the side panels (not the shell) to get the wires outside? Minimally modifying the factory wheel is a nice challenge, so only damaging the side plates that would be nice, you could get spare ones and reconstruct the original. I also imagine only attaching the "bag" to the ACM handle with fastened bolt or something, but not permanently. If I ever build that thing.

[US69]

21 minutes ago, meepmeepmayer said:

Expanding batteries should be relatively simple, right? Are the inter-battery connections a problem (I read here somewhere that, optimally, all batteries should be connected to each other for balancing and safety)? Can it be done by only making a hole (or two) in the side panels (not the shell) to get the wires outside? Minimally modifying the factory wheel is a nice challenge, so only damaging the side plates that would be nice, you could get spare ones and reconstruct the original. I also imagine only attaching the "bag" to the ACM handle with fastened bolt or something, but not permanently. If I ever build that thing.

Take Care!!! Plugging batteries together can get quiet dangerous if you dont know what you do!

When they are connected permanent, you must ensure charging/decharging goes parallel and balanced! And as the 2 big packs are connected by a Special balancing wire, it is not so easy to get inbetween! When first connected same voltage of all packs is needed!!!

When you think of a "outside" Version, it is also absolutly needed that the voltage of your "extra" batteries are on the exact same voltage as the inside batteries!

Between any packs no voltage different is allowed! Otherwise Explosion may happen!

(That is just Basics...not to mention the seriell balancing of each pack on it's own!)

[meepmeepmayer]

@KingSong69 Don't worry, it's going to be a long long time (if ever) before I do this The same voltage requirement is obvious. On first connection, you just charge all batteries 100% and connect, is that safe enough? The interconnections - not sure: for a 2400Wh monster (3 batteries), are there 3 connections (between each pair of batteries) in addition to the charging wires?

[US69]

4 minutes ago, meepmeepmayer said:

@KingSong69 Don't worry, it's going to be a long long time (if ever) before I do this The voltage requirement is obvious, the interconnections - not sure: for a 2400Wh monster (3 batteries), are there 3 connections (between each pair of batteries) in addition to the charging wires?

I havent seen a Monster inside yet...but i know that on all newer GW models(v3-ACM) the both side batteriepacks are connected one pair for charging, one pair for de-charging(powercables) and one time by a 4 strand cable directly between the both packs. So i would guess they go for this security installment also on the Monster.

[Rehab1]

  GW responded to my email and I also received my new hall sensors. I would like to replace the hall sensors with the original type if possible. The new hall sensors are about 1 mm smaller than the OEM version. I still need to test the sensor characteristics with the old one, if possible. Being there were no legs left on the hall sensor to act as a heat sink was there too much heat from my soldering gun to damage the internal electronics? 

 

[meepmeepmayer]

Good to hear Gotway service will respond to requests that aren't their "fault" (so to speak). Not bad for such a small company