Building my first e-bike, questions

I tested everything, and it seems to work fine on the bench, This controller works pretty nice, the default pretty much run without brakes or pedal sensor connected, and it is 36 or 48 volt compatible.
Here is where I show my ignorance what is 12g? I am getting info from the maker as to the length and tension of the spokes Monday. The work was really simple, anyone that can solder could splice color for color, It took a couple of hours in total, and I would've been watching TV or something useless otherwise. I guess I could've been working a Jukebox amp I have on the bench.
 
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Good job! 12g is 12 gauge , size (diameter) of the spoke.

edit: did you twist the heavy gauge phase wires together before soldering (to get copper to copper contact)? Or just laid them next to each other before soldering (no copper to copper contact)? Solder melts at t lower temperature than copper. If the phase amps is too high for the solder to handle, it will melt. If your motor stops working one day after climbing a steep hill, check those solder connections. It would have been better if you used crimp connectors for those high current phase wire connections.
 
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s-petersen said:
Here is where I show my ignorance what is 12g?
Click to expand...

That's 12 gauge spokes, which are made from wire 2.7mmn in diameter. It's a common mistake among electric bike buyers and manufacturers to use spokes that are too thick for bicycle rims. Either they won't stay tight, or they damage the rims, or both.

Use 14ga, 13-14ga single butted, or 14-15ga double butted spokes and you'll have much better results.
 
Chalo said:
That's 12 gauge spokes, which are made from wire 2.7mmn in diameter. It's a common mistake among electric bike buyers and manufacturers to use spokes that are too thick for bicycle rims. Either they won't stay tight, or they damage the rims, or both.

Use 14ga, 13-14ga single butted, or 14-15ga double butted spokes and you'll have much better results.
Click to expand...
How does that work? Gauge of the spokes has to match the strength of the rim? Stronger rims such as motorcycle rims, which are wider, thicker, and smaller in diameter need heavier gauge spokes? Is there a formula for choosing spokes?
 
Zambam said:
How does that work? Gauge of the spokes has to match the strength of the rim?
Click to expand...

Spokes must be stretched elastically to work. The thicker they are, the more tension it takes for them to follow the rim's flexing under load without going slack. But if the rim can't withstand that much tension without buckling or cracking, then the thick spokes will slacken constantly in normal operation, loosening and chafing against the other parts.

Zambam said:
Stronger rims such as motorcycle rims, which are wider, thicker, and smaller in diameter need heavier gauge spokes?
Click to expand...

They don't need thick spokes, but they can tolerate the higher tensions that thick spokes require.

There isn't a formula for spoke gauge as far as I know, but bicycle rims of any kind work best with 14ga (2.0mm) or thinner spokes.
 
Zambam said:
edit: did you twist the heavy gauge phase wires together before soldering (to get copper to copper contact)? Or just laid them next to each other before soldering (no copper to copper contact)? Solder melts at t lower temperature than copper. If the phase amps is too high for the solder to handle, it will melt. If your motor stops working one day after climbing a steep hill, check those solder connections. It would have been better if you used crimp connectors for those high current phase wire connections.
Click to expand...
I wove them together, but if it does get hot enough to melt the solder, they could possibly come apart, so if it fails, next time I will crimp, and solder. Good Idea!
 
s-petersen said:
I wove them together, but if it does get hot enough to melt the solder, they could possibly come apart, so if it fails, next time I will crimp, and solder. Good Idea!
Click to expand...
Never got my motor wires very hot at all, but others have and posted their pictures. Seems like the connectors often melt first. If not that, then the insulation on the phase wires melts. Both short circuit the harness and fry parts in the controller. The hot rodders who have super heavy motor wires will see the solder in the motor windings melt while the enamel burns off the core windings,

If you did a good job soldering your cable, it will probably be OK. The big concern is that solder is brittle, so the solder area needs some strain relief. I used to put a splint around a motor cable where I soldered it.






.
 
s-petersen said:
I wove them together, but if it does get hot enough to melt the solder, they could possibly come apart, so if it fails, next time I will crimp, and solder. Good Idea!
Click to expand...
How's the project going? 2 wires wove together then solder is better than laying 2 wires next to each other then solder.

Just came across this video by Will Prowse of DIY Solar where he talks about crimping vs soldering lug connections.
 
Still waiting on parts, The pedal sensor came (it was missing from the kit) the wiring does not match, so I had to order some pigtails to mate it to the controller, the spoke tools are also on order. The weather has been too crappy to work on it outside. I still need to get the pedal removing tools to install the sensor, The rear rack for the battery is also on it's way.
Pretty good video!
 
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