Jrkline "Wheel Whisperer" Posted February 23, 2017 Share Posted February 23, 2017 14 hours ago, Rehab1 said: If I were to wager I would bet the solder connections are performed ultrasonically and not by an employee using a hand held soldering gun. Unfortunately if the ultrasonic equipment is not dialed in properly adequate flow of the solder between the wire and connector will never be accomplished. Having toured the Gotway facility in Shenzhen in Oct. 2016 with @Linnea Lin Gotway ,The assembly area is a room with workstations butted together 2 abreast down the center with less than 50 total.All assembly appeared to be done at these stations as there were the new v3's in various stages of assembly at different stations(no automation),so if the connectors are assembled at Gotway as opposed to being already attached from the outside vendor who supplies the control boards,then they are all hand soldered.Every component appeared to be assembled by hand.The assembly area at the King Song facility is very similiar.Not enough product volume to justify expensive automation. Link to comment Share on other sites More sharing options...
Marty Backe Posted February 23, 2017 Author Share Posted February 23, 2017 2 minutes ago, jrkline said: Having toured the Gotway facility in Shenzhen in Oct. 2016 with @Linnea Lin Gotway ,The assembly area is a room with workstations butted together 2 abreast down the center with less than 50 total.All assembly appeared to be done at these stations as there were the new v3's in various stages of assembly at different stations(no automation),so if the connectors are assembled at Gotway as opposed to being already attached from the outside vendor who supplies the control boards,then they are all hand soldered.Every component appeared to be assembled by hand.The assembly area at the King Song facility is very similiar.Not enough product volume to justify expensive automation. @jrkline you insist upon raining on our ever hopeful visions of Gotway and KingSong as first-class manufacturing enterprises. Please let us have our dreams Link to comment Share on other sites More sharing options...
Jrkline "Wheel Whisperer" Posted February 23, 2017 Share Posted February 23, 2017 6 minutes ago, Marty Backe said: @jrkline you insist upon raining on our ever hopeful visions of Gotway and KingSong as first-class manufacturing enterprises. Please let us have our dreams You seem to operate under the false assumption that lack of automation precludes first-class manufacturing.Tell that to the buyers of the McClaren car who typically pay more than $1Mil and wait over a year for their assembled by hand supercar! Link to comment Share on other sites More sharing options...
Smoother Posted February 23, 2017 Share Posted February 23, 2017 6 hours ago, jrkline said: You seem to operate under the false assumption that lack of automation precludes first-class manufacturing.Tell that to the buyers of the McClaren car who typically pay more than $1Mil and wait over a year for their assembled by hand supercar! Yeah, there's nothing wrong with hand made, unless one of the workers is ham fisted, or inept, or didn't understand the training, or doesn't give a shit, or has a grudge against the company, or had a bad night, or is hung over, or is sick but doesn't want to take the day off, or whose soldering iron is malfunctioning, or they left their glasses at hipbone that day. Other than that, hand made is perfect ( I'm joking of course). I think one of those workers @jrkline walked past is the "Typhoid Mary" of the Gottway production line. Link to comment Share on other sites More sharing options...
Marty Backe Posted February 23, 2017 Author Share Posted February 23, 2017 Bravo. It's rare indeed to be able to juxtapose Typhoid Mary and EUCs, but very fitting. I salute you Link to comment Share on other sites More sharing options...
Pingouin Posted February 23, 2017 Share Posted February 23, 2017 Hi, I will be testing my new gotway in extreme situations (high speed and stiff climb in the rocks), I have put some hot glue on it, after the ride I will look at it and check if it has deformed, if it has it means the connectors are getting really hot, if they didn't move I would probably conclude that on my unit at least the solder isn't getting that hot, I'll keep you guys updated Link to comment Share on other sites More sharing options...
Smoother Posted February 23, 2017 Share Posted February 23, 2017 1 hour ago, Pingouin said: Hi, I will be testing my new gotway in extreme situations (high speed and stiff climb in the rocks), I have put some hot glue on it, after the ride I will look at it and check if it has deformed, if it has it means the connectors are getting really hot, if they didn't move I would probably conclude that on my unit at least the solder isn't getting that hot, I'll keep you guys updated Take some " before" pictures otherwise you might end up going ' did it? Didn't it? I'm not sure. Take some before pictures of your face too! Just saying. That's sounds like a test in down town face plant city, to me. I'll shut up now ? Link to comment Share on other sites More sharing options...
Pingouin Posted February 23, 2017 Share Posted February 23, 2017 I've already closed the wheel, but if it melts down it will be quite obvious as the three wires are glued together, I hope I won't face plant but I'm prepared for it, I'll be doing it in the moutains so there will berely be anyone to witness a ridiculouse faceplant if it does happen, plus I wouldn't risk anyone in my experiment, but my girlfriend will be following me on the E-bike so it I get serious injuries at least I won't be stuck like an idiot ^^ I am quite young and maybe it helps, because the last times a wheel shut down on me, I have never ever been injured physically even at +30kph, I've always managed to run and finish either on the coat or in the grass. Link to comment Share on other sites More sharing options...
esaj Posted February 23, 2017 Share Posted February 23, 2017 My guess would be that the connectors don't actually heat up enough to melt the solder (around 183-190 Celsius for leaded compounds, but since these are probably RoHS-compliant, it's non-leaded with melting point somewhere around 215-230 Celsius or so), but that the soldering job wasn't that good on the first place. Should the connector temperature rise that high during riding, I'd expect the plastic parts of the connector to melt first or at the very least show signs of melting... Even if the wires don't move around inside the compartment, there's a pretty constant vibration going on when the wheel's being ridden, and over time, the bad joint comes off due to this at some point. Making proper joints on copper connectors requires that both the wire and the connector (or at least the area where the contact between them is) get heated high enough for proper "wetting action/intermetallic bonding" to take place (ie. it's not just a blob of solder holding things together, but the materials have partially "welded" together, forming a combination of the metals). In the above, "Cu6Sn5" is an alloy formed in the junctions (or interfaces, or whatever is the correct English term) of the materials from the tin (Sn) in the solder and copper (Cu) of the connector/pad/wire/whatever during soldering, ie. the copper has also melted and mixed with the tin to form a strong bond. Large tip, high heat and flux helps... Link to comment Share on other sites More sharing options...
Jrkline "Wheel Whisperer" Posted February 23, 2017 Share Posted February 23, 2017 6 hours ago, Smoother said: I think one of those workers @jrkline walked past is the "Typhoid Mary" of the Gottway production line. It's kind of ironic,but "Typhoid Mary" may be the perfect description for my visit.It was on a Tuesday afternoon and no one was working in the assembly area.It wasn't a production line as much as a "ghost line".Then again,it could just be that a lot of Chinese take long lunch breaks. 1 hour ago, esaj said: My guess would be that the connectors don't actually heat up enough to melt the solder (around 183-190 Celsius for leaded compounds, but since these are probably RoHS-compliant, it's non-leaded with melting point somewhere around 215-230 Celsius or so), but that the soldering job wasn't that good on the first place. I concur.It may also just be a bad design.When I first started supplementing my wheels with extra batteries,I was surprised how the two types of connectors commonly used for the battery connections had no holes to insert the end of the wire through to acheive a better solder connection like you find commonly on switches and such.Whenever I add a connector for an additional battery,the first thing I do is drill little holes in the connector tabs to insure a much greater solder connection and lessen the possibility of failure due to vibration. Link to comment Share on other sites More sharing options...
Marty Backe Posted February 23, 2017 Author Share Posted February 23, 2017 3 hours ago, Pingouin said: <snip> I am quite young and maybe it helps, because the last times a wheel shut down on me, I have never ever been injured physically even at +30kph, I've always managed to run and finish either on the coat or in the grass. Please go away Link to comment Share on other sites More sharing options...
Cerbera Posted February 23, 2017 Share Posted February 23, 2017 2 hours ago, Marty Backe said: Please go away Yes I agree - he must be the first human in all time to be able to accelerate from standstill to 30 kph+ in under a second. I'd certainly like to see the video Link to comment Share on other sites More sharing options...
Pingouin Posted February 23, 2017 Share Posted February 23, 2017 It's just for flex in the knees, not for fast acceleration, I think I need a few more seconds to reach 30kph ^^ Link to comment Share on other sites More sharing options...
Hunka Hunka Burning Love Posted February 24, 2017 Share Posted February 24, 2017 On 2/22/2017 at 4:53 PM, steve454 said: That seems like a good idea, and you wouldn't have to disconnect any wires in the first place like you would with heat shrink tubing. I was thinking if you bought a large enough diameter heat shrink it might fit over the connector, but I don't know if it would shrink enough to form a tight grip onto the wire. I think it probably would as I've played with a few heat shrink tubes before, and they usually can shrink quite a bit. @Marty Backe - I know you probably don't like to fix what's not broken (yet), but considering the higher speeds you're achieving and where you're riding with the Gotways, a little preventative intervention before something cuts off going up a steep hill might be a good idea. We'd hate to see our favorite Gotway rider have an accident related to something like a failing connector joint! I'd like to see you be able to boast that you've ridden 10,000 miles without any incident going up the steepest hills and down the deepest valleys all over Cali. Now that is something we'd all be happy to hear about... Link to comment Share on other sites More sharing options...
steve454 Posted February 24, 2017 Share Posted February 24, 2017 On 2/22/2017 at 7:07 PM, Marty Backe said: Heat Shrink Tape Whoa, I didn't know that existed. I have some liquid electrical tape, but heat shrink tape would seem to be stronger. I googled it, and sure enough it is a good option. Link to comment Share on other sites More sharing options...
steve454 Posted February 24, 2017 Share Posted February 24, 2017 19 hours ago, Smoother said: Yeah, there's nothing wrong with hand made, unless one of the workers is ham fisted, or inept, or didn't understand the training, or doesn't give a shit, or has a grudge against the company, or had a bad night, or is hung over, or is sick but doesn't want to take the day off, or whose soldering iron is malfunctioning, or they left their glasses at hipbone that day. Other than that, hand made is perfect ( I'm joking of course). I think one of those workers @jrkline walked past is the "Typhoid Mary" of the Gottway production line. That reminds me of the Dire Straits song, Industrial Disease. One bad worker can spoil the product. But that applies in any industry. I believe in general that the good quality wheels are well made. The more the wheel costs to buy, the better quality it will be, in general. Link to comment Share on other sites More sharing options...
Marty Backe Posted February 24, 2017 Author Share Posted February 24, 2017 32 minutes ago, Hunka Hunka Burning Love said: I was thinking if you bought a large enough diameter heat shrink it might fit over the connector, but I don't know if it would shrink enough to form a tight grip onto the wire. I think it probably would as I've played with a few heat shrink tubes before, and they usually can shrink quite a bit. @Marty Backe - I know you probably don't like to fix what's not broken (yet), but considering the higher speeds you're achieving and where you're riding with the Gotways, a little preventative intervention before something cuts off going up a steep hill might be a good idea. We'd hate to see our favorite Gotway rider have an accident related to something like a failing connector joint! I'd like to see you be able to boast that you've ridden 10,000 miles without any incident going up the steepest hills and down the deepest valleys all over Cali. Now that is something we'd all be happy to hear about... Thanks for that Maybe I'll be the Control Group - anything for the team Link to comment Share on other sites More sharing options...
Hunka Hunka Burning Love Posted February 25, 2017 Share Posted February 25, 2017 @esaj I've seen what would barely pass as what we call "wire" used in power cords attached to cheap power supplies from China. It was more brown than metal coloured, and looked like human brunette hair! It would not surprise me if someone concocted a low melting solder which might be "good enough" for low current situations, but it might not be rated similar to conventional solder you see on the market. The cost cutting is pretty extreme in some Chinese products I've seen. I'd be curious to see someone measure the melting temperature of the solder used in the Gotway connectors. In that video in the first post, the yellow wire and the connector both have a decent blob of solder visible which makes me think it must have gotten molten at some point to let go with vibration. Check out this paper with some solder liquid temperatures at 58 C. http://www.hpl.hp.com/hpjournal/96aug/aug96a10.pdf Hopefully with the switch over to crimped connectors we won't be hearing about these connection failures in the future. @Pingouin how heavy are you? I wonder maybe if you aren't heavy enough, even climbing a steep road might not be enough to generate enough heat in your situation. It could be dependent on rider weight and prolonged load on the wheel to get to the point of failure? Link to comment Share on other sites More sharing options...
Pingouin Posted February 25, 2017 Share Posted February 25, 2017 I weight 60kg, and from 62 to 65kg while riding, but the climbs i'll be doing will be at high speeds during several minutes, so it should give the machine a hard time, but I can't be much heavier than I am :/ Link to comment Share on other sites More sharing options...
Marty Backe Posted February 25, 2017 Author Share Posted February 25, 2017 1 hour ago, Pingouin said: I weight 60kg, and from 62 to 65kg while riding, but the climbs i'll be doing will be at high speeds during several minutes, so it should give the machine a hard time, but I can't be much heavier than I am :/ It's harder to be lighter, but heavier? You could help the community by strapping a 45 pound barbell on your back. That should give the wheel a good stress test Link to comment Share on other sites More sharing options...
Smoother Posted February 25, 2017 Share Posted February 25, 2017 5 hours ago, Marty Backe said: It's harder to be lighter, but heavier? You could help the community by strapping a 45 pound barbell on your back. That should give the wheel a good stress test Not just the wheel. The only thing worse than a face plant is a face plant followed by an spinal assault from a 45lb bar bell, ouch. Hey, but, it all in the name of science, so go for it. We all do our own stunts, after all. Link to comment Share on other sites More sharing options...
Marty Backe Posted February 25, 2017 Author Share Posted February 25, 2017 43 minutes ago, Smoother said: Not just the wheel. The only thing worse than a face plant is a face plant followed by an spinal assault from a 45lb bar bell, ouch. Hey, but, it all in the name of science, so go for it. We all do our own stunts, after all. Link to comment Share on other sites More sharing options...
Pingouin Posted February 25, 2017 Share Posted February 25, 2017 I can carry a backpack than weights 15kg, it would place me at 77-78kg riding weight, if the solder doesn't melt down I won't faceplant because I won't go above the third warning beep ^^ Link to comment Share on other sites More sharing options...
Smoother Posted February 25, 2017 Share Posted February 25, 2017 32 minutes ago, Pingouin said: I can carry a backpack than weights 15kg, it would place me at 77-78kg riding weight, if the solder doesn't melt down I won't faceplant because I won't go above the third warning beep ^^ No, do t do it. It was just a joke. That 15kg could hurt you, and neither I nor @Marty Backe would want that on our conscience. Right Marty? Just ride really really fast. No wait, that was a joke too. Be safe, peace?? Link to comment Share on other sites More sharing options...
esaj Posted February 25, 2017 Share Posted February 25, 2017 22 hours ago, Hunka Hunka Burning Love said: @esaj I've seen what would barely pass as what we call "wire" used in power cords attached to cheap power supplies from China. It was more brown than metal coloured, and looked like human brunette hair! It would not surprise me if someone concocted a low melting solder which might be "good enough" for low current situations, but it might not be rated similar to conventional solder you see on the market. The cost cutting is pretty extreme in some Chinese products I've seen. I'd be curious to see someone measure the melting temperature of the solder used in the Gotway connectors. In that video in the first post, the yellow wire and the connector both have a decent blob of solder visible which makes me think it must have gotten molten at some point to let go with vibration. Check out this paper with some solder liquid temperatures at 58 C. http://www.hpl.hp.com/hpjournal/96aug/aug96a10.pdf While I have no doubt such alloys exist, I doubt the cost-savings on using something else than "normal" soldering tins would be anywhere substantial enough to warrant for using such Actually I suspect that the alloys mentioned are more expensive than typical Sn/Ag or Sn/Pb (leaded) soldering tins, as they're likely not mass produced (don't know if the paper said anything about the costs, didn't read it that closely ). Poor quality wires are another thing, many of the silicone wires I've ordered from China have used aluminum conductors instead of copper, which, although not exactly a bad conductor does have its problems (oxidizing layer)... Could the brown stuff you saw have been (partially) burned and then dried flux residue? Or just badly oxidized copper (although copper usually becomes more dark green than brown over time)? The flux leftovers are usually clear or brownish (if heated enough), and if left there and let dry, become something like a "tar-like" substance: I actually cleaned it up though, so no picture of the dried stuff: 22 hours ago, Hunka Hunka Burning Love said: Hopefully with the switch over to crimped connectors we won't be hearing about these connection failures in the future. If done right (and/or with the right tools, ie. usually specific crimping pliers built for the connector), crimping should hold pretty well. For very large wires (larger than in our wheels), it's also said to be pretty much the only "reasonable" method, as you can hardly solder something like 16mm^2 or larger wires properly (without a blow torch or something). Personally, with all the vibration etc. mechanical shocks the wires/contacts take all the time, I'd still go with soldered contacts (or crimping and soldering)... I still stubbornly hold to my theory of bad soldering job giving up, rather than the actual solder melting, but could be wrong (bad contact means higher resistance, which means higher power dissipation at the contact, which then maybe, just maybe, could cause enough heat locally to melt the solder?). Still it would need quite a lot of heat and happen fast enough not to melt the plastics around the connector Either way, hopefully they'll get their s**t together fast and we won't hear of anymore cases of the wires coming off mid-ride. Link to comment Share on other sites More sharing options...
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