Cable issue with Varla Eagle One

seriouslyrobert

So I’m not exactly sure what’s happening, but after a suggestion on one of the Facebook groups, I feel it’s the most likely issue.

When I turn right, only right, the front motor/wheel starts vibrating like crazy and bogs down. I’ve checked there’s nothing rubbing or in the way. I’ve checked all my settings are correct. When I put it on single mode it works fine.

Someone suggested that I have a pinched cable since the problem is directional. This is highly possible since I have dropped the tire/motor off of support a couple times while changing.

So how would I go about checking this? If this is the case, how would I fix it?

Thanks

PaulN

From your description that this only happens “under load” I disagree that it is something mechanical or a pinched wire on the outside surrounding the motor. This sounds like the hub motor itself has some kind of internal issue under power.

babblefish

From your description of the problem, my guess is your front motor is intermittently losing one of its input power phases. You say it runs fine in one wheel drive which makes sense since the front motor is turned off and only the rear motor is doing all the work. Let me explain. The majority of our scooters use 3-phase brushless motors and they work by getting pulsed DC power from the speed controller sequentially through three wires going into the motor. If any one of those three wires should lose its pulsed power source the motor will still try to run but very erratically due to the missing pulse. Sort of like a regular multi cylinder gas engine losing one of its cylinders. It’ll keep running but will be shuddering and shaking. In your case, the cause could be internal to the motor, but since you say it starts acting up when the steering is turned then I would suspect one of those three motor wires has a broken wire within its insulation due to being pinched or one of the electrical connectors for one of those three wires is suspect. Too bad you’re not close by to me because I have the equipment and the knowledge to troubleshoot the problem.

PaulN

babblefish So my brand new scooter seems to be doing this on the rear wheel It worked beautifully for 20 -25 kms mostly driving in first “gear” under 45 kms per hour one wheel drive. Then I started to go up a slight hill and the rear wheel made a strange louder sound, vibrated, stuttered and lost all torque. Luckily there of course are 2 motors on a scooter so I got home ok. Any suggestions to troubleshoot this. I have voltmeters meters to check voltages etc. so I can order the correct warranty part from Yume.

babblefish

PaulN
Sounds like the same problem. I posted a wiring diagram of a generic wiring diagram. I would check the connections pointed to by the red arrow. There are the 3 phase wires suppling power to the motor and the Hall sensor connections. I probably wouldn’t worry about the Hall sensor connection as that would mainly affect how the motor responds from a dead stop. For the 3 phase wires, you can check for continuity (ohm setting on a multimeter) for each of the three wires. Do this with the scooter turned OFF! You’ll have to somehow connect one probe end right where the wire comes out of the controller and the other probe end as close to the motor as possible. I usually do this by poking a fine needle through the wire insulation into the wire inside and connecting the probe to the needle. As you’re checking each wire/phase, turn the steering from left to right to see if the connection is lost.
If your motor connections between the motor and controller is with a yellow plastic block like shown in the picture, then I would make sure the screws that clamp the wires together are nice and tight.

PaulN

babblefish Thanks I just got a chance to log on here and saw this. I will look more closely at this tonight when I’m home. I rode the Phantom in to work today. Thanks for taking the time to post this.
Mine is the rear wheel btw.
If i raise the scooter on a box if the wheel is in certain positions and i pull the throttle its dead. Then if i rotate the wheel even just an inch by hand and try again it takes off right away. Seems like there is no real torque though until it is spinning faster. So it will spin, but its noisy, and “vibratey”.
I hadn’t thought to open the deck up and check for a loose connection like in your picture though. I assumed the wire connectors inside would all be tight push-on’s and nothing on a screw terminal block. Can’t hurt to eliminate any possible causes like the ones you suggest. I’m afraid to look in there i imagine with all the LEDS there will be a mess of wires as soon as a lift the acrylic lid.

babblefish

Note that the motor wire colors (green, yellow, blue) may not match from the controller to the motor (i.e. green to green, blue to blue) as it is in the picture (my scooter). This is NOT a mistake and they should be left connected as the factory has them. If you match the wire colors it won’t hurt anything but your motor will spin in the wrong direction.

babblefish

If you’re losing one of the motor phases by turning the steering, it could be either a problem internal to the motor or the wire from the controller to the motor. I highly doubt if it would be a controller problem because turning the steering would not affect the controller.

babblefish

It is pretty scary under there. One of the reasons I opened mine up was to disconnect all of the annoying “ambiance” LEDs.
I also had to disconnect both wheel motors in order to install the new brake rotors.

PaulN

babblefish
I owe you a big thank you here.
Yume suggested I swap the controller outputs front to back to see if the problem moved to the other wheel.

I had some things to do over our long weekend here so i finally got around to removing the deck plate yesterday. As soon as i pulled out cable for the rear motor i could see one of the wires just drop away from the yellow terminal box. 2 of the terminals obviously were not tightened correctly at the factory. (Exactly like your picture) I couldn’t even find the nut on the one at first. (it was melted into the top cover) So I cleaned up the charring checked all the other connections while i was in there - The front wheel terminals were tight. I have some liquid electrical tape, so I put a few drops on all the terminal nuts. I didn’t want to use Loctite because to remove ever again would be a chore. What a mess of wires in there though. I work for a local sales office for a German machinery company. If they saw this wiring I’m not sure if they would laugh or cry or both. Honestly i would like to clean it up and label some of them one day.

So today i drove it into work, the motors worked great, unfortunately the rear fender screws and brake light screws, started to fall out one by one, (I tightened these when i first got the scooter already) I keep some rubber bands in my backpack and the the little hex tool as well so I “only” had to stop twice to just make it in to work. I replaced all the factory screws with new ones and with lock washers and better compression nuts, and a little dot of removeable Loctite. Luckily I have all this at work. (What a QC disaster so far) Before I drive back home I’ll go over every bolt again. I’m not trusting the scooter at any high speeds yet.

Thanks for your assistance again.

babblefish

Glad you were able to fix it and glad I was able to help. Did the problematic connector block have a top cover on it (like the one on the left side in my picture (the one with a “F” on it). If so, I would have thought it would have kept the nut from falling off and the connection from separating. A lot of current passes through those connections so if they’re even just loose then all kinds of arcing and burning can happen causing running issues.

babblefish

I’ve been wanting to tidy up the birds nest of wiring under my deck by cleaning up the wire routing and shortening wires that don’t need to be so long. That’ll help cooling too by opening up more air space. Labeling the connections would also help immensely for any future troubleshooting that might be needed in the future.

PaulN

babblefish
The cover was was just sitting in the bottom of the tray I had to pick it out, the nut melted into it. I wrapped electrical tape around the cover and block now so it can’t fall off as well.

PaulN

Lovin’ the structured chaos of the wires in the deck 😀

babblefish

The loose connectors were arcing and heated up the nut which promptly melted into the top cover. It’s amazing how the trained monkeys back in China are able to cram all those wires under there and get the deck to sit flat. Luckily I’m an experienced electronics engineer so all that wiring is just meh to me. I’m also amazed the motor controllers are able to survive with no air flow to keep them cool. I’d love to figure out a way to add some kind of cooling without allowing water to enter the compartment. I never ride in the rain and I avoid puddles so maybe I can get away with drilling a few holes backed with wire mesh to help get rid of excess heat.

PaulN

babblefish
Agreed i was wondering about the heat as well, I won’t drive in the rain either. But with road dust and you can’t avoid every puddle (people watering lawns or park paths) even putting a small filter and a computer fan might make more issues than not. I also was thinking of making a simple air deflector for the back motor to redirect air at the aluminum body motor and rim to cool them a little more efficiently. Something as simple as a soft body curving tube with an angled outlet. Nothing sharp or metal.

babblefish

PaulN This guy came up with a motor cooler for a Loatie ES19 that looks interesting. Maybe you can adapt that idea for your scooter.

PaulN

babblefish
That is a bit strange. how does the flow work with that butted up against the motor body. He should have brought a little smoke beside the fan to see if it gets sucked it and pushed through the rim gap to the other side?

babblefish

PaulN Yeah, I’m not sure how air is supposed to flow through. There is the big opening on the side of his contraption where the air nozzle sticks out.

PaulN

babblefish
I will probably try to rig up the Yume first. The way the rear fender is mounted, its perfect to easily rig up a mini ram air style tube or a plastic deflector that i have in mind. Even to just test to see if it helps temporarily nothing needs to be drilled or glued. I can tie wrap something in place. I’m driving 90% rear wheel only on all my scooters anyway.