The weight weenie died (NO JOY)

LewTwo

1 MW
Joined
Apr 8, 2014
Messages
2,119
Location
Houston, Texas
Well it finally happened: it died. I was coming back from the grocery store and everything was fine … then it happened: complete shutdown. Cycle the battery on and off …. nothing. Turn on the power and the motor goes bump and then absolutely nothing.

Unplug the system and check battery voltage … 40 volts (pretty good for a six year old 36 volt LiFePo4 battery). Plug it back in, turn on the battery and the power immediately drops to zero. Unplug the throttle and same, same. Unplug the motor and power to the controller stays on with 40 volts on the input. It appears that the BMS immediately shuts down the system when it starts feeding current to the system. I think it is detecting a direct short.

Motor: Bafang WSXU geared front hub motor
Controller: S-KU65 DC-24 to 36 Volts

Motor spins freely forward, cogs when turned in reverse.

Hmmmmm … unplug the battery:
check the resistance through controller and motor: 4.5 ohms
unplug the motor
check the resistance through the controller: 1.5K ohms … rising

check motor phase:
Yellow to Green = 0 ohms, generates current when spun backwards
Green to Blue = 0 ohms, generates current when spun backwards
Blue to Yellow = 0 ohms, generates current when spun backwards

I have one of those Brushless Motor/Controller testers but it’s connectors have no resemblance to mine. That is because I have a Julet 9 conductor motor cable hard wired to the controller. Might have to hard wire Julet male/female cable pair to the tester.

Removed the controller and took it apart. One solder join for the power shunt melted and dripped down to the case leaving a scorch mark on the rear cover plate. Also found another smokey bit on the bottom of the circuit board.

At this point all I want to do is verify that the motor is still good … not sure how to do that without a known good controller.
scorch mark1.JPG
scorch mark2.JPG
PCB Smoky Bit(1280).JPG
 
I remember that bike.
There were better controllers than the KU series from BMS Battery when you built the Weight Weenie and the ones today are Waaay better.
Psw Power has a nice line-up of sm. sensorless models;
https://www.pswpower.com/collections/controller
Even if it's the Halls, one of these will put you back on the road. The sensorless feature works much better than the controllers from the KU era.
But I must say the KU was durable.
 
motomech said:
I remember that bike.
There were better controllers than the KU series from BMS Battery when you built the Weight Weenie and the ones today are Waaay better.
Psw Power has a nice line-up of sm. sensorless models;
https://www.pswpower.com/collections/controller
Even if it's the Halls, one of these will put you back on the road. The sensorless feature works much better than the controllers from the KU era.
But I must say the KU was durable.
I barely remember, but I am old an senile. This one was not so durable it seems. This is a picture of the top side of the PCB where I found the smoke bit on the bottom. Note the resistor in the center of the ellipse ??? :cry:
PCB Smoky Bit2.JPG
I decided that the female (HiGo Z910) 9 conductor cable stub was more valuable than the controller. I am going to splice it onto a Grin Phase Runner (the old 'transparent' model with actual cables on it) and Cycle Analyst DPS V2. Then I will give that a go. I will pray that there is nothing seriously wrong with the motor that smoked the controller before I apply power. :?
Julet 9 Pin Connector Pin-Out (standard).jpg

oops ... just noticed I have two pins numbered "5" on the female connector. Have to fix that. :oops:

... FIXED
 
Update .... if anyone is interested
Nothing is ever simple .....

Splice Phase Runner Motor Cable to Julet Female Cable:
I spent a lot of time trying to verify the wires to be joined between the two cables.
X1.jpg
Plus two unterminated Wires: Dark Gray, White = ???
(speed, thermistor or something else)

Matching color codes ….. well, not exactly …. another hiccup: the Phase Runner’s hall cable has two additional undocumented wires. The ends of these are stripped and twisted together … I do not recall having done that (but being old and senile I might have and forgotten it). I need to get Grin to verify those wires should or should not be connected to each other.

No response from Grin but I did find this post:
https://endless-sphere.com/forums/viewtopic.php?f=2&t=106249&start=25
X2.jpg
If I have read that correctly then those two wires are for an remote on/off switch.

Now we come to the wire sizes. I was going to do a quick crimp splice just to test the concept. Now here is the thing: The Phase Runner’s power cables are 12 AWG. Most of the Julet 9 conductor cables use phase conductors that are 18 AWG. Grin uses 1.5 mm2 (about 16 AWG) phase conductors in their Z910 cable. Did you ever try to use a crimp butt splice between 12 and 18 AWG stranded wires? It is even worse if you use HEX dies like I usually do. The Morris 12-10 copper butt splices just fall off the Phase Runner’s wire unless I neglect to remove the insulation. I have to use the next smaller size. The signal cables are 24 AWG in both cables … of course no one makes crimp butt splice for 26 AWG wire. I found that if I twisted the wires together that I could use a non-insulate ferule end for 20 AWG wire for a good substitute. For testing purposes (proof of concept) I did a really ugly splice by twisting the ends of the wires together and then crimping a ferrule round them. If this works as hoped then I will mark the proper cable length (they are all going to be way too long) and do a proper splice.
Splice 02 (1280).JPG
I will add some heat shrink before I apply power.

X3.jpg
Nearly all E-Bike throttles come with cables that are terminated with spade terminals. The conductors are also tiny … on the order of 28 AWG (the phase runner signal wires are 24 AWG). I went to my JST connector box to terminate the throttle cable with a matching JST Female (has pins). Oops, all I have is JST connectors for PCBs. “Hello Amazon, I need some … When? That would be yesterday.” I am going to need to add another 50 caliber ammo box to my growing collection of connectors.

For the test case scenario I installed a JST-SM male (has sockets) on the throttle cable. I can use a jumper wires to join the two connectors to get her. I am none too proud of my crimps on those tiny wires but I reckon that they will hold.

Need Laptop/Tablet to program Phase runner:
Unfortunately I can not test this thing without a computer :(
Linux Mint is currently installed on my HP Elite X2 Tablet.
Unfortunately Linux does not play nice with this HP tablet.
So I have to reinstall Windows 10 on the HP Elite X2 Tablet.
I figure installing all the Microsoft and HP updates will take most of the rest of the evening.
Then I need to do a few things to make the Windows User Interface a little less user hostile.

So maybe I finally get to test the motor tomorrow morning.
 
COAR said:
Can't you run a virtual machine on the tablet? Probably a lot quicker than a full OS install...
In theory but it only has 4 Gbytes of ram and an Intel core m3-6y30 CPU @ 0.90 Ghz.
Both are soldered to the motherboard so no upgrade options either.
It does work well for Amazon Kindle and Google Chrome which is why I have it.

The only reason I installed Linux on it was because the previous Windows Installation crashed trying to do updates (the BIOS has since been updated). Linux installed and most things work but not very well. So it is back to Windows 10 Pro. I have got the updates done, networking fixed and Google Chrome installed as well as Amazon Kindle but I am tired. Still need a PDF reader (other than Kindle) and Libreoffice (I want to be able to take notes if I have a problem). Then I can download the Grin PDFs and software.
 
COAR said:
You can use Chrome as a PDF reader. I prefer having Adobe reader though in case I want to mark anything up.
I installed Sumatra PDF Reader. I works.

I heard that one could use Libreoffice draw to edit a PDF file but my experience is that it sometimes renders the fonts improperly. That is a problem for the back burner/around-to-it box.
 
Well I spent most of the day trying to get past the problems (OMG do I hate Windows !!!).

NO JOY ...
Failed (1280).jpg
I tried both sensor and sensorless mode (I even cut all the hall connector wires). I Also reversed the direction (several times). Ether I screwed up the wiring, failed to understand the software or there is something wrong inside the motor.

At some point in time one needs to know when to walk away and find an alternate solution. As this is currently my only transportation I ordered a EBIKELING 700C front wheel kit via Amazon:
https://www.amazon.com/dp/product

I chose this kit because:
1) Quick deliver (next monday)
2) 36 volts (I think it may actually work on 48 volts as well)
3) It looks like it will replace the current front wheel and associated components (controler, display, throttle)
4) Motor/wheel weight is 7.4 pounds (3.3 KG)
5) Price
6) Quick deliver (next monday)

CONS:
Black carbon steel spokes (seriously) ????
Black center of wheel does not match rear wheel.
Maybe at some point I will relace hub into the existing rim (with stainless steel spokes).

If I was not in such hurry I would have gotten the Bafang G311 Standard Wind Front Geared Hub but I figure the time involved in shipping from Canada, getting the correct spokes and rebuilding the wheel would exceed the current limits of my kitchen pantry.

I really do want to get a known good Bafang Motor and see if I screwed something up ....
 
I really do want to get a known good Bafang Motor and see if I screwed something up ....

Why didn't you get one of these?
https://jag35.com/collections/accessories-1/products/26-bafang-36v-dc-electric-bike-wheel-tire-w-tektro-disk-break
I know you know about them because you posted in an on-going thread about them;
https://endless-sphere.com/forums/viewtopic.php?f=3&t=111160&hilit=jump
 
motomech said:
I really do want to get a known good Bafang Motor and see if I screwed something up ....

Why didn't you get one of these?
https://jag35.com/collections/accessories-1/products/26-bafang-36v-dc-electric-bike-wheel-tire-w-tektro-disk-break
I know you know about them because you posted in an on-going thread about them;
https://endless-sphere.com/forums/viewtopic.php?f=3&t=111160&hilit=jump
Two Reasons: time and risk.

I need to get this up and running very quickly. Piecing bits together from various sources increases the chances for a simple mistake ordering the wrong bit and having a delay getting the replacement. I also seem to recall some something about the wheels. Among other things they are painted 26 inch rims. The fork on my frame is a really narrow 700C road bike fork. Max tire size is 700x28C. The EBIKELING kit has a 19mm width caliper compatible 700C rim with all the matching bits and pieces parts. I should be able to have it up and running within and a couple of hours of receiving the kit.
Pakage Arival.png
I did find another Bafang motor to get for 'test bench' purposes: https://www.ebay.com/itm/393292066607

That is a new, small, light weight, Bafang 250 watt, 36 volt FM G320.250.R. It has a shimano roller brake mount. I figure that does not matter as I will not be mounting it in a rim and will not need a brake (infamous last words). FYI this motor has the similar (same?) quite helical cut reduction gears and roller bearings as the Bafang G311. Same seller also has the 350 watt version with disk mount for the same price. I think that is the same motor as JAG is selling.
 
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