Gotway Tesla Impressions and Diary

[mezzanine]

Great work on the pics, @Hunka Hunka Burning Love.  Your comment about the axle size caught my attention because that's the improvement KS69 mentioned that I was most glad to see.  I'm particularly interested in whether you can see any change to the shim used the assembly that has deformed over time for Monster riders, especially.  The Korean Gotways use better quality shims and I'm curious whether the Tesla ones are different than the standard ACM/Monster/MSuper.  I had assumed that a larger axle was another way of solving this problem.  

Right now it looks like I may have been a little premature in celebrating improvements at Gotway with the Tesla.  You and KS69 have juxtaposing observations about whether there have been upgrades.  I was surprised when KS69 mentioned it looked like there were upgrades because I would have expected them to be present in Tishawn's teardown video.  I rationalized it by figuring Tishawn's was a prototype and there may have been final revisions. 

What you observe about their being a lot of room inside is good news for @Marty Backe and those who would like to see a v2 with a larger battery option.  Do you think it would be possible to do 1600wh without significantly widening the case?  I'm still a newb when it comes to battery dimension trade offs in shell design. 

 

It's fun when there are members getting new wheels.  I'm living vicariously through you. 

 

Edited November 9, 2017 by mezzanine

[Marty Backe]

4 minutes ago, mezzanine said:

Great work on the pics, @Hunka Hunka Burning Love.  Your comment about the axle size caught my attention because that's the improvement KS69 mentioned that I was most glad to see.  I'm particularly interested in whether you can see any change to the shim used the assembly that has deformed over time for Monster riders, especially.  The Korean Gotways use better quality shims and I'm curious whether the Tesla ones are different than the standard ACM/Monster/MSuper.  I had assumed that a larger axle was another way of solving this problem.  

What you observe about their being a lot of room inside is good news for @Marty Backe and those who would like to see a v2 with a larger battery option.  Do you think it would be possible to do 1600wh without significantly widening the case?  I'm still a newb when it comes to battery dimension trade offs in shell design. 

 

It's fun when there are members getting new wheels.  I'm living vicariously through you. 

 

If they could get the capacity to at least my ACM (1300wh) then I'd be happy(ier).

I doubt @Hunka Hunka Burning Love is going to totally disassemble his Tesla to get at the shims, but it's winter and cold there, so who knows 

[Hunka Hunka Burning Love]

Although there is room in the case for extra plastic reinforcement of the side panel mounting points, there does not appear to be room for extra or larger battery packs unless they design expanded side panels to go laterally in dimension.  That would tend to make the wheel too wide I think.  Unless they move to 20700 batteries or do a @smallexis custom battery stash I don't readily see higher than 1020 wh capacity happening without an extensive shell redesign. Maybe with a split battery pack of 132 wh or something in each side that might give you over 1300 wh without making the sides too wide?  It might be possible...

I'll open up the other side later, but I bet the trolley handle also limits things.  They made this shell streamlined as the outer edges are concave, and although it looks pretty good that way, it really limits how many batteries you can stash in there.  It's nice that it doesn't resemble a PC computer case, but at the same time a wheel has to kind of resemble a computer case if you want more battery capacity.  Just look at the Msuper, ACM, and Monster.  They have large, rectangular shaped casings that you can pack mega batteries into.  They also weigh a ton.  The Tesla appeals to people wanting to go moderate distances at a fair clip who don't want to lift a massively heavily wheel.  Going from 18 km to 60-80km (?) will be a breath of fresh air in reducing range anxiety.

Regarding the shims, I bet they are the same as in the ACM and MSuper?  Gotway wanted a slightly softer metal to help avoid axle damage which makes sense in a way.  If the axle was larger or they used a different attachment method that weak spot could be minimized.  I don't plan on crashing my wheel (famous last words) so hopefully the shims will last.  I weigh 167 lbs so I'm probably within the design specifications for shim longevity I'm hoping.  If you look at my Ninebot with 1400 kms on it now, I've never placed much padding on it except under the pedals.  It's still in pretty good condition.  It uses a similar shim system that Gotway likely borrowed from.

I tried riding it about 5 feet in my kitchen, and it felt pretty solid.  I don't know what setting it is on from the factory as I haven't tried the app yet.

Edited November 9, 2017 by Hunka Hunka Burning Love

[LanghamP]

7 minutes ago, Hunka Hunka Burning Love said:

 Going from 18 km/h to 60-80km/h (?) will be a breath of fresh air in reducing range anxiety.

 

Fixed it for you.

Having several wheels with both internal and external trolleys, I've come to dislike internal ones as they require too many compromises to pack inside.

I think the trolley that bolts onto the footpegs is perfect, it protects the wheel on crashes, easy to replace, and when it bends you kick it back straight. It doesn't go inside the wheel and so leaves all that wonderful room for more important things like battery and motor.

[Hunka Hunka Burning Love]

I might be crazy, but I'm not that crazy!  I keep looking at the plasticky Tesla with the baby sized screws, thin hall sensor wires and flimsy trolley handle and think - THIS thing is going to propel me balanced on a single tire at 50 kph?  Do I have a deathwish?    I don't think so.

I'll probably end up keeping it under 40 kph until I get a chin guard helmet, motorcycle pants, and more disability insurance!

The exploded view on the box is pretty neat to look at.  It's missing the side panel trim pieces though.

Nut measures 7/8"

Or about 23 mm?

Axle diameter is 13 mm

Battery space is limited.

While on and idling there is a muted high pitched frequency sound that is a lot quieter than other Gotway wheel videos I've seen.  In comparison though my Ninebot is completely silent while idling.  You can't even tell that it is on.

Here you can see what the problem was with the cable side panel by viewing the trolley side panel.  They trimmed it down by about 3-4 mm on the other panel.

Edited November 9, 2017 by Hunka Hunka Burning Love

[Meng Yang]

7 hours ago, KingSong69 said:

Finally, finally Gotway has managed to come back to a real rock hard pedal setting with no play at all!(which i last saw on the Mcm2s)!

Idling on this wheel is a pleasure, as it is reactive and powerfull enough to shift you back and forth with ease!

For me, drive and riding mode wise, the best 16inch wheel available! What also stands out, that it  is relatively quiet ...

Absolutely!

Likewise, on my Tesla, footrests doesn't dip and is extremely responsive to my every shift in weight & balance - when in Sports mode. Its powerful enough to act to my every input. Its a pleasure to pendulum back & forth. And its eerily quiet; and before I know it, I'm already up there in the 40s in speed. 

Edited November 9, 2017 by Meng Yang
grammer

[stevedig]

Hall effect sensors do trickle a small current across a thin strip of metal. It's a very small current however and is applied to allow the detection of voltage gradients produced by the variance in magnet field across the strip of metal. The passing magnet produces a voltage spike that is detected by the sensor to determine position of the motor magnets. This doesn't require heavy gauge wiring. Unless the sensor wires are under some stress that would require additional strength... Why are you concerned?

[Hunka Hunka Burning Love]

These wheels under go a tremendous amount of vibration at speed (moreso if you're Marty Backe going off-road ).  I would be concerned about frictional wear over time.  In fact I saw some battery charging cable insulation in my GW Tesla that was slightly pinch damaged already.  Nothing major, but for an important component I'd rather have it over-engineered.  What is the cost of heavy gauge wiring compared to thin wiring?  I'd happily pay $50 more for that extra piece of mind on a $1300-1500 wheel.  Unfortunately the wiring space in the axle appears limited still so we won't be seeing an improvement there until the axle size is increased or unless they go the KingSong route and pass the hall sensor wiring through another hole in the axle on the other side.

Low voltage wiring can be thin, but do you want it to be that narrow in essential systems like in a helicopter or plane that you are travelling in that manages critical circuitry?  Vibration along with age can cause insulator wear, degradation and short circuits.  Unlikely you say?  Why take that risk?

http://www.vision.net.au/~apaterson/aviation/kapton_mangold.htm

I guess I just would feel more secure with heavy duty wiring everywhere.  I don't want to see such slim wires on a wheel that goes over 50 kph.

Edited November 9, 2017 by Hunka Hunka Burning Love

[Marty Backe]

1 hour ago, Hunka Hunka Burning Love said:

I might be crazy, but I'm not that crazy!  I keep looking at the plasticky Tesla with the baby sized screws, thin hall sensor wires and flimsy trolley handle and think - THIS thing is going to propel me balanced on a single tire at 50 kph?  Do I have a deathwish?    I don't think so.

I'll probably end up keeping it under 40 kph until I get a chin guard helmet, motorcycle pants, and more disability insurance!

The exploded view on the box is pretty neat to look at.  It's missing the side panel trim pieces though.

 

Nut measures 7/8"

 

Or about 23 mm?

 

Axle diameter is 13 mm

 

Battery space is limited.

 

While on and idling there is a muted high pitched frequency sound that is a lot quieter than other Gotway wheel videos I've seen.  In comparison though my Ninebot though is completely silent while idling.  You can't even tell that it is on.

Here you can see what the problem was with the cable side panel by viewing the trolley side panel.

 

ACM and MSuper use 21mm nuts, so they have indeed increased the size of the axle. The Monster uses a 24mm nut. Maybe it's 24mm? Anyway, that's very nice.

The Mten3 has no whine, probably just like the Tesla. Looks like they've figured it out. My new KS14S however has a whine more reminiscent of the older Gotway wheels.

[Marty Backe]

13 minutes ago, Hunka Hunka Burning Love said:

These wheels under go a tremendous amount of vibration at speed (moreso if you're Marty Backe going off-road ).  I would be concerned about frictional wear over time.  In fact I saw some battery charging cable insulation in my GW Tesla that was slightly pinch damaged already.  Nothing major, but for an important component I'd rather have it over-engineered.  What is the cost of heavy gauge wiring compared to thin wiring?  I'd happily pay $50 more for that extra piece of mind on a $1300-1500 wheel.  Unfortunately the wiring space in the axle appears limited still so we won't be seeing an improvement there until the axle size is increased.

Low voltage wiring can be thin, but do you want it to be that narrow in essential systems in a helicopter or plane that you are travelling in that manages critical circuitry?  Vibration along with age can cause insulator wear, degradation and short circuits.  Unlikely you say?  Why take that risk?

http://www.vision.net.au/~apaterson/aviation/kapton_mangold.htm

I'm no structural engineer, but I would think small, light, wires would be less susceptible to vibration related damage than heavier, thicker wires. Same goes for where they connect to the sensors. 

[Hunka Hunka Burning Love]

I rechecked on the cable side, and I think the nut is 23 mm unless my eyes are wonky with the parallax.  With all things being equal thinner wiring might wear slower due to less mass to vibrate, but small nicks during installation could compromise them as well.

One problem I did find is this in the following photo.  I think it is one of the thinner charging or balancing wires.  It is thicker than the hall sensor wiring.  It looks to be torn likely due to the hard, sharp edge of the blue shrink wrap?  I trimmed some of the wrap away and placed some electrical tape for the time being.  I might try to repair it with some epoxy later on.  Gotway might consider some cable sheathing for the wire bundle coming out of the battery packs.  That is exposed wiring.

Electrical tape temp repair.

Location of wire exit.

Any tips on how to repair wire insulation without cutting the wire to insert heatshrink tubing?

Edited November 9, 2017 by Hunka Hunka Burning Love

[Marty Backe]

14 minutes ago, Hunka Hunka Burning Love said:

I rechecked on the cable side, and I think the nut is 23 mm unless my eyes are wonky with the parallax.  With all things being equal thinner wiring might wear slower due to less mass to vibrate, but small nicks during installation could compromise them as well.

One problem I did find is this in the following photo.  I think it is one of the thinner charging or balancing wires.  It is thicker than the hall sensor wiring.  It looks to be torn likely due to the hard, sharp edge of the blue shrink wrap?  I trimmed some of the wrap away and placed some electrical tape for the time being.  I might try to repair it with some epoxy later on.  Gotway might consider some cable sheathing for the wire bundle coming out of the battery packs.  That is exposed wiring.

Electrical tape temp repair.

 

Location of wire exit.

 

That wire obviously does not look good  Kudos for the thorough inspection. Fortunately that's an easy one to fix and probably would never have caused a problem. But COME-ON Gotway, time to startup upping your QA game! Jeesh. You seeing this @KingSong69?

[Hunka Hunka Burning Love]

I'm just glad it was one wire and not two next to each other.  It's probably not a huge issue, but looking at this photo Ninebot has a bundle sheath on its battery pack.  Or maybe at least give the Gotway workers free nail clippers?    I wonder whether using stronger insulation wiring might help.  I've seen wiring with pretty tear resistant insulation.  Maybe it isn't as temperature resistant?  The wiring in the Gotway packs seems to be more a soft silicone that likely tears easier.

Edited November 9, 2017 by Hunka Hunka Burning Love

[US69]

15 minutes ago, Marty Backe said:

That wire obviously does not look good  Kudos for the thorough inspection. Fortunately that's an easy one to fix and probably would never have caused a problem. But COME-ON Gotway, time to startup upping your QA game! Jeesh. You seeing this @KingSong69?

Yip, that wire doesnt look good. No probs on my Tesla with this

Guys, for the axle and motor wire measuring....i compared it to what i know from my V3 and GW quality until today...i didn’t say is perfect now 

Definitly the axle diameter has become thicker...from the numbers Hunka throws in i would say 2mm.

For the motor wires, most significant to me is that they are “one strand” wires now, you can definitly feel that when trying to bend them. As the axle did go 2mm thicker...i would guess they used that place also for the wire hole and the wire diameter? From what i can say, these are more sturdy than on my old V3.

@Hunka Hunka Burning Love For the motor signal wires, these are in this size on all wheels i know and from my experience, no need to worry. i would say on a KS they are not thicker, also. Things to worry on a GW, are the Mosfets, and perhaps extensive long high grade hills... and for the last, they allready did some progress by changing motor connectors and wires. 

Edited November 9, 2017 by KingSong69

[US69]

@Hunka Hunka Burning Love

by looking at the wire on the last photo, yes, seams to be the connecting balancing wire to the other batterie pack.

As long as only the silicon around that wires was stripped a bit, i would say no need to worry.

But here, and also on the rough plastic magnet rim cut (melted on mine) we see, that the understanding of quality control we have is totally different to Gotways. Sometimes it seams the quality of your wheel depends on the shift or or single worker who is working on your wheel. So still lot of room for improvement:-)

[Marty Backe]

1 minute ago, KingSong69 said:

@Hunka Hunka Burning Love

by looking at the wire on the last photo, yes, seams to be the connecting balancing wire to the other batterie pack.

As long as only the silicon around that wires was stripped a bit, i would say no need to worry.

But here, and also on the rough plastic magnet rim cut (melted on mine) we see, that the understanding of quality control we have is totally different to Gotways. Sometimes it seams the quality of your wheel depends on the shift or or single worker who is working on your wheel. So still lot of room for improvement:-)

As I noted in my KS14S Side Pad thread, the right-side pad was installed with a different technique than the left-side pad. Chinese production processes are like the Japanese in the 1960's. They have a loooooooooong way to go.

[US69]

@Hunka Hunka Burning Love And to your motor connectors:

they are much to near to this screw, which is holding the heatsink...try to place them somewhere above, that nothing can happen in case the heatshrink is away. When i see that on your photo, i remember the chinese Tesla “smoking” failure...there where rumours, that the motor wires shorted with a screw of the heatsink, but these were never confirmed. But popped in my mind directly after seeing your photo! On my Tesla the connector is over the middle of the board, even a bit worse placed....i have to work on that, also!

Edited November 9, 2017 by KingSong69

[Hunka Hunka Burning Love]

I'm still quite happy that Gotway have taken steps and seem to be listening to the community suggestions put out there.  I for one want all EUC manufacturers to thrive and do well as it gives us options to choose from.  It would be a boring place if we all drove Honda Civics.

I just hope there never occurs a bad fire due to batteries shorting or a EUC charging fire due to small issues like some of which we've mentioned.  That sort of thing basically decimated the hoverboard industry, and they never escaped the stigma.

I did notice the motor cabling is quite stiff so maybe it is solid core wiring?  It's marked 14 AWG coming from the control board.  That would be a little odd if they went that route, but maybe it conducts electricity better with lower heat production as the mass of copper is greater as a whole?

Edit: Regarding the motor connectors I was going to try to separate them a bit and place some sort of insulation between them to try to avoid any issues.  You would think that they could stagger the position of the connectors by using different length wiring for each phase and complimenting lengths on the other side so the metal connectors are located away from each other.  Again it might not be an issue,  but if that clear covering ever wears or melts the connectors wouldn't be next to each other.

EXAMPLE A:  Staggered placement of connectors

Edited November 10, 2017 by Hunka Hunka Burning Love

[US69]

And finally to the battery size:

Thats why i stated in. my first post, that in november 2017....i have the biggest battery version (and that might change) ;-)

From my -quite ok - battery knowledge....to pop this thing up from 1020wh to 1600wh(1600wh is btw the same cell number than 1300wh), all that is needed is an extra layer of 20 cells on each side! Now you have on each side a brick of 2x20cells...which has to be upgrade to 3 x 20 cells.

One cell measured as 18mm wide...but, as these are layered “diagonal” ...another layer of 20cells on each side, would just make this pack about 12mm wider on each side...not 18mm.

Conclusion: It is very easy to upgrade from GW side...just a bit different sidepads are needed, a bit wider!

So just the same they did on the Msuper V3 and on the Acm.

I am pretty sure they WILL come out with that...2 months perhaps! And than (again)i will be pretty angry :-)

[US69]

6 minutes ago, Hunka Hunka Burning Love said:

notice the motor cabling is quite stiff so maybe it is solid core wiring?  That would be a little odd if they went that route, but maybe it conducts electricity better with lower heat production as the mass of copper is greater as a whole?

 i dont think thats odd, thats a good choice....and this is btw. the same on my Ks18S...

The motor wires are now solid core, thats what i wanted to say with “one strand” (is that a wrong translation?)

 

[Hunka Hunka Burning Love]

They are pretty close in meaning.  I thought there was some discussion previously about why multi-stranded wiring is usually used due to its greater flexibility.  I always thought solid core wiring was superior as there are no air spaces in the wiring.  Lack of flexibility is a drawback though.  There was also some discussion about skin effect.  I never knew KS moved to solid core wiring.  That's very interesting.

Edit:  I asked this question previously:

 

Edited November 9, 2017 by Hunka Hunka Burning Love

[Marty Backe]

2 hours ago, Hunka Hunka Burning Love said:

I'm still quite happy that Gotway have taken steps and seem to be listening to the community suggestions put out there.  I for one want all EUC manufacturers to thrive and do well as it gives us options to choose from.  It would be a boring place if we all drove Honda Civics.

I just hope there never occurs a bad fire due to batteries shorting or a EUC charging fire due to small issues like some of which we've mentioned.  That sort of thing basically decimated the hoverboard industry, and they never escaped the stigma.

I did notice the motor cabling is quite stiff so maybe it is solid core wiring?  That would be a little odd if they went that route, but maybe it conducts electricity better with lower heat production as the mass of copper is greater as a whole?

Edit: Regarding the motor connectors I was going to try to separate them a bit and place some sort of insulation between them to try to avoid any issues.  You would think that they could stagger the position of the connectors by using different length wiring for each phase and complimenting lengths on the other side so the metal connectors are located away from each other.  Again it might not be an issue,  but if that clear covering ever wears or melts the connectors wouldn't be next to each other.

When my ACM wires melted and shorted, the connectors did not. It was the wires that melted together. So my take away is that if you really want to minimize cable melting, separate the wires. Only separating the connectors isn't going to help much.

So it's my understanding (correct me if I'm wrong) that you don't climb long steep hills. I don't think you need to worry about cables melting 

[Hunka Hunka Burning Love]

After re-examining my battery wiring, I highly recommend users double check the wiring exit point from the battery packs.  Due to the new design, the wires exit at the corner of the batteries and take a sharp bend so there is a moderate chance that the blue battery shrink wrap edge may have sliced or damaged the silicone insulator on some of the wires.  As previously mentioned, one of my wires had exposed strands, and there was evidence of other wires having sliced cuts into the insulation.

I used a sharp pair of fine scissors to trim back some of the blue shrink wrap near the area to help prevent it from slicing the wiring.  You will will notice the sharp edges of the plastic.  Be very careful not to cut into the wires if you decide to trim back the blue heat shrink.  84V is not to be messed with unless you are extremely cautious.  You need a fine pair of manicure scissors to complete this task.  Make sure you do not cut and end up with an even sharper edge.

Hopefully Gotway will be proactive on this and consider using protective wire harness tubing / heatshrink for the battery wiring bundle before shrink wrapping the blue plastic covering over the pack as the edges end up being sharp and possibly cut into the wiring.

Sharp bend on exit from pack.  I've trimmed back some of the blue plastic.

Edited November 9, 2017 by Hunka Hunka Burning Love

[Hunka Hunka Burning Love]

34 minutes ago, Marty Backe said:

When my ACM wires melted and shorted, the connectors did not. It was the wires that melted together. So my take away is that if you really want to minimize cable melting, separate the wires. Only separating the connectors isn't going to help much.

So it's my understanding (correct me if I'm wrong) that you don't climb long steep hills. I don't think you need to worry about cables melting 

I skimmed over the video, and at 19:50 it looks like the plastic connectors melted together,  but they didn't short.  I distinctly remember it thinking that it confirmed several suspicions that the connectors were hot spots in addition to the wiring.  I think as you mentioned that separating all the motor cables along with connectors where possible is likely prudent.

I don't climb long, steep hills with my Ninebot, but now that I got this fancy 1900W speed monster it's very tempting!    I just like being proactive to catch any weak spots before they do me in.  That's one thing I've learned reading the posts in the Gotway forum.

Edited November 9, 2017 by Hunka Hunka Burning Love

[US69]

1 hour ago, Hunka Hunka Burning Love said:

I skimmed over the video, and at 19:50 it looks like the plastic connectors melted together,  but they didn't short.  I distinctly remember it thinking that it confirmed several suspicions that the connectors were hot spots in addition to the wiring.  I think as you mentioned that separating all the motor cables along with connectors where possible is likely prudent.

There has been two Problems with the ACM/Msuper:

First it have been the bad soldering and the to small connectors which produce resistant and so heat builded up and so the connectors melted the plastic and shorted!

Then the connectors have been made stronger and were crimped!

Then the next fault came up, like on Marty's wheel-> the wires melted, and the conclusion was that -at all- the wires are not thick enough for the produced amperage on such agressive hills!

 

But now: We have double as fat connectors, crimped adn soldered! And solid core thicker wires!

While i would still guess there is a -small- Chance to overheat the wires/connector....i guess now you must have four times the Long hill and/or much more weight on the wheel.

And i am personnaly NOT going to test something like that....who knows: perhaps now we have that solid wires that before melting the Chance of a mosfet Pop or overheat is bigger :-)

 

In the end it is quite easy-> i would have not pushed anymore on an long hill like that in Marty's Video, if i would have feeled that my wheel really got Trouble to climb it up.

So the main advise would be: Listen to your wheel :-)

Edited November 9, 2017 by KingSong69