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Combining 2 VESCs with CANBUS or Y-CABLE?

vesc

#1

Guys I know there is a canbus cable but can I just get a cheap Y splitter cable on ebay for a buck instead? Any disadvantages from the CANBUS cable? What connector plug type does it use? I know it’s just a black and white cable. Any thoughts are greatly appreciated.


Servo and canbus
#2

The VESC is capable of traction control if you connect two over CAN


#3

Ok so that’s good to know. Can I make that connection myself? Thanks again!


#4

you can, i dont know the connector type.
you also can simply buy it

Or you can solder the connection


#5

I’d like to solder it but …have u done it or have advice?


#6

If you have spare computer parts or a spare computer case, you can use the power button/LED wires for the connection, you’ll need to snip the wire and put another header on there though.


#7

Or if you have an Raspberry / Arduino, you can use two single gpio wires


#8

The CAN bus connection is nothing more than just two wires. It can’t get any simpler than that.


#9

Is there a risk of overheating the rest of the board?

Also you’re the only person I’ve come across who has an explaination for how voltage reduces heat in a motor. I remember long ago you explained it as similar to an ac circuit or something…could you again!? It was a while ago. As of lately I can’t find such an explaination


#10

Thank you. That’s just the answer I expected! I’ve read that the CANBus is only for data transmission. It still needs additional wires for power? More research and reading to do! Thanks guys.


#11

Power equals Voltage x Current : P=U x I
So for any given Power, Voltage and Current will be inversely proportional.
Raise the voltage and the current will drop proportionally.
Dissipated heat is quadratically proportional to current.
If you halve the current, you quarter the heat.


#12

#13

I don’t have much soldering skills, so I crimp both ends of both wires and connect to a 4 pin JST-PH 2mm female connector. Then connect to male connectors in each VESC.
Here is a picture of how I made it.
http://www.electric-skateboard.builders/uploads/db1493/original/2X/c/cfeba170a336a6d581be09e5f60ad901e6c1d3ec.JPG


#14

But you get the same heat to torque ratio regardless of what winding you have. So running a given motor at 100 volts and one amp will produce the same heat as a motor at 1 volt and 100 amps. Do u have a link that better explains what you’re saying about the dissipated heat being quadraticly proportional to current?
If you raise the voltage on a given motor the current won’t drop unless the winding has more turns. More turns means thinner wire and greater resistance and more heat. I read they end up the same
You can’t just add more volts to the same motor and expect it to run cooler in fact it will run hotter as the motor is most efficient running at 80% of its no load rpm. This is what I read

Volts x amps being power I think is more so a potential. In terms of power out… Torque x speed. Speed is a potential of voltage but not a gaurentee


#15

Thanks sgaana! Where did you get those JST-PH connectors? I assume eBay as well since I’ve seen them before. What wire gauge did you use for the two wires? Thank you for the picture references.


#16

Local electronics store.
I’m not sure about wire gauge size. I explained to my local store what I was going to build and they said any wire would work, as long as you can crimp them.
I am not too handy and did not have tools to do this. I ended spending money buying tools and tried tens of times before I got it right. But it was a nice learning experience.
You can buy from some members of this forum for reasonable price and they are well made, unlike mine. .


http://www.hellray.de/shop/#!/eSkateboard-JST-PH-2mm-Kabel-für-VESC-mit-4-Pin/p/60319783/category=15255004 (you need only two middle wires)


#17

FALSE.

Look up the equation for Joule Heating, you’ll find the heat produced is proportional to I squared.

P= V x I is one of the most basic electrical engineering equations out there. It doesn’t matter if it’s a toaster putting out 500W or a brushless motor putting out 2500W, this equation governs the relationship between Power, Current and Voltage.

With respect, If you want to doubt this, feel free to do so, but don’t try to convince me.

Now let’s not hijack this thread any further.


#18

We will see. Ur changing the situation. I’m interested. But too tired. I’ll find you a good rebuff in the morn


#19

heat produced is related to the thickness and length and material of the wire and ultimately it’s resistance

Power … I don’t know. Do you believe that if you add 100 volts to the set-up you’re running now it will be more efficient?


#20

Dude, why the hell do you think electrical power distribution networks run at voltages in the kiloVolt range and not just plain 110V or 230V ?
I’m done discussing the obvious.