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EUC Motors Are Not Waterproof!


Rehab1

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Today I tore into my wife’s old KS14C to salvage the axle for @Smoother. The wheel ended up at the bottom of a lake on June 12, 2017 and was submerged for approximately 60 minutes. The wheel has been setting around my shop for the past 7 months.

Upon removing the motor side covers I was shocked how much water had infiltrated the motor. Yes there is a huge difference between riding through puddles and completely submerging a wheel in water but my concern is any moisture entering the motor will cause a catastrophic failure. I plan to avoid any large puddles in the future. 

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1 minute ago, Rehab1 said:

Today I tore into my wife’s old KS14C to salvage the axle for @Smoother. The wheel ended up at the bottom of a lake on June 12, 2017 and was submerged for approximately 60 minutes. The wheel has been setting around my shop for the past 7 months.

Upon removing the motor side covers I was shocked how much water had infiltrated the motor. Yes there is a huge difference between riding through puddles and completely submerging a wheel in water but my concern is any moisture entering the motor will cause a catastrophic failure. I plan to avoid any large puddles in the future. 

39737101252_17e5c2fb25_b.jpg

 

27990250479_6d0d7d0fc8_b.jpg

 

27990679219_6b890e98cc_b.jpg

 

I really don't think puddle riding is something to worry about. We just don't hear about water related failures from all the people that ride in the rain or ride through puddles.

KingSong takes some serious metal away from those axles. I wonder how thin it gets?

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6 minutes ago, Marty Backe said:

I really don't think puddle riding is something to worry about. We just don't hear about water related failures from all the people that ride in the rain or ride through puddles.

I agree. It is a bit concerning though. 

7 minutes ago, Marty Backe said:

KingSong takes some serious metal away from those axles. I wonder how thin it gets?

 1mm or .0394

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22 minutes ago, Rehab1 said:

I agree. It is a bit concerning though. 

 1mm or .0394

39059743824_878c4a3827_b.jpg

 

Whew! That's a relief. Plenty thick for the average Chinese rider. Oh wait, you're not Chinese are you?

I would insert modified picture of you as a Chinese man, but I might be called racist if I did :(  So you'll have to use your already overactive imagination.

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To what depth was the EUC submerged? I remember images of the truck in the water and recall the wheel was on the back seat? Pressure at depth would have greatly increased the chance of water ingress. 

Is there any kind of seal around the side panels where they measure with the  motor to help keep water out? 

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48 minutes ago, Marty Backe said:

I would insert modified picture of you as a Chinese man, but I might be called racist if I did :(  So you'll have to use your already overactive imagination.

If your going to make me get out my glasses to read such small print............here you go:

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40 minutes ago, WARPed1701D said:

To what depth was the EUC submerged? I remember images of the truck in the water and recall the wheel was on the back seat? Pressure at depth would have greatly increased the chance of water ingress. 

Is there any kind of seal around the side panels where they measure with the  motor to help keep water out? 

I don’t have an precise calculation of depth but the water was just below the roof top of my Dodge Ram which is 76” tall. The wheel was sitting in the back seat ...so maybe 2 feet deep? There are no physical rubber seal just a machined lip. 

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21 minutes ago, LanghamP said:

I've worn condoms that were thicker.

Sorry, that reminded me of the Monty Python movie where King Arthur asked someone to explain again how sheep's bladders could be used to prevent earthquakes.

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When I took mine apart there was a type of silicone gasket goo on the shells. They had to be pried off the rim. The bearings are mostly sealed, but, as I learned from my recent bearing research, there are over a dozen styles, and some seal better than others, but none are submersion proof for more than a quick splash.  Then there is the tight, but unsealed surfaces between the bearing and shell, and axle.  Again, not for prolonged submersion.  The chief suspect for a totally submerged wheel, is the channel drilled for the wires. There was a bit of goo on mine, but I would say it was more of a box-checking exercise by the assembler, rather than a concerted effort to seal the opening.  When mine goes back together there is going to be an unholy mess of silicone in that axle hole.

I would say, that as long as the gasket goo was applied correctly to the rim, one could safely ride in several inches of water.  Just don't drop it in the drink. chinese fountain video comes to mind. (this is not a recommendation) 

@Rehab1 that does look to be the correct axle.  In the 1st. photo the boss clearly looks like 25mm.  When you get the bearing off the other side, the shaft should measure 23mm.  The axle that replaced this model has a 17mm shaft, and 2 more mm on the ends, but they still went to the "lets have another guess" school of engineering, because, if they were capable of learning from their own mistakes, they wouldn't have shaved it at all, or barely, and not with a sharp edge to concentrate stress forces.

Here's another thought: seperate hall sensor wires from motor wires and feed them through opposite ends of the axle.  Why? To facilitate a smaller bore hole, and retain the axle strength. 

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1 hour ago, Rehab1 said:

If your going to make me get out my glasses to read such small print............here you go:

39060333454_10e7ae4ae3_b.jpg

 

:laughbounce2::roflmao:

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59 minutes ago, Smoother said:

In the 1st. photo the boss clearly looks like 25mm.  When you get the bearing off the other side, the shaft should measure 23mm. 

Removing the other bearing is a challenge. My ACM was the same way. I’ll get it off. 

 

1 hour ago, Smoother said:

Here's another thought: seperate hall sensor wires from motor wires and feed them through opposite ends of the axle.  Why? To facilitate a smaller bore hole, and retain the axle strength. 

That sounds feasible.

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3 hours ago, LanghamP said:

I just realized no one mentioned the truck. I didn't even think about the truck either, but isn't the truck worth much more than the wheel?

:crying:

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10 hours ago, Smoother said:

Here's another thought: seperate hall sensor wires from motor wires and feed them through opposite ends of the axle.  Why? To facilitate a smaller bore hole, and retain the axle strength. 

Meanwhile thats done on all new KS wheels since KS18S (not sure for the 16s)

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25 minutes ago, KingSong69 said:

Meanwhile thats done on all new KS wheels since KS18S (not sure for the 16s)

I've watched the only 3 vids on YouTube about KS tire replacement and all show only one wheel cable;  14d, 16xx  and 16s.  Do you know which models you are referring to?  When did the 18S come out?

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2 hours ago, Smoother said:

I've watched the only 3 vids on YouTube about KS tire replacement and all show only one wheel cable;  14d, 16xx  and 16s.  Do you know which models you are referring to?  When did the 18S come out?

Puuuh, i dont know exactly...July 2017? So if the 16S doesnt have it...it is only the 18S and the upcoming 18L then.

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5 hours ago, Smoother said:

Why? what does good winding look like?

Good quality armatures will look very clean with no wires crossing over each other.  

54b36168db986.jpg

The highest efficiency motors will have windings neatly laid next to and on top of each other and will be tightly packed.  And to get the absolute most efficiency flat or square wire is used to virtually eliminate all air gaps.  Total turns per phase is directly proportional to torque.  So putting all the needed turns (N per phase) in a single coil with smaller magnet wires and then paralleling the coils will yield extra space for more turns.  KS looks to be using 6 wires in parallel...just not wound as efficiently as it could be.

The windings on this stator look much cleaner and he has what looks like 12 wires in parallel for each coil (plus look at his mad skills soldering SMD caps and a resistor directly on the legs of the hall sensors):

I have a Ninebot One P motor that has a bad hall sensor....I've been meaning to open it to see if I can replace the sensor(s).  When I do, I'll post some pics for comparison.  :) 

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6 minutes ago, Cranium said:

Good quality armatures will look very clean with no wires crossing over each other.  

54b36168db986.jpg

The highest efficiency motors will have windings neatly laid next to and on top of each other and will be tightly packed.  And to get the absolute most efficiency flat or square wire is used to virtually eliminate all air gaps.  Total turns per phase is directly proportional to torque.  So putting all the needed turns (N per phase) in a single coil with smaller magnet wires and then paralleling the coils will yield extra space for more turns.  KS looks to be using 6 wires in parallel...just not wound as efficiently as it could be.

The windings on this stator look much cleaner and he has what looks like 12 wires in parallel for each coil (plus look at his mad skills soldering SMD caps and a resistor directly on the legs of the hall sensors):

I have a Ninebot One P motor that has a bad hall sensor....I've been meaning to open it to see if I can replace the sensor(s).  When I do, I'll post some pics for comparison.  :) 

Thanks for the expanded explanation. I love to learn what constitutes quality in any particular endeavor. We still have a lot of room for improvements in our EUCs. Someday - hopefully.

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