[Fire Hazzard] Wire Size for two Sabertooth 2X12

Help & Support Robot Parts
1

Hello,

I’m trying to drive 4 motors with 2 Sabertooth hooked-up to a single 3S 50C 3700mah Lipo Battery. (11.1v)
Just fond out that the regular jumper wire arent meant for this task. Had hooked up the Sabertooths via jumper cables on a breadboard and all jumper cables literally melted. Lol…
It was all good when I was working with just one Sabertooth, the moment I put a second Sabertooth in parallel, the insulation of jumper cables on the breadboard all melted away. It was a bit scary… with the smoke n all…

I am used to working with L298n and i guess i never really bothered thinking about sizing the wire… The jumper cables worked just fine on L298n

With Sabertooth I gotta be more careful i presume.

So, what is the recommended wire size to

  1. Drive 4 motors https://www.robotshop.com/ca/en/12v-58rpm-60-1-gear-motor-encoder.html
  2. attached to 2 dual 12A Sabertooths https://www.robotshop.com/ca/en/sabertooth-dual-regenerative-motor-driver.html
  3. attached to one 3S 50C 3700mah Lipo Battery. (11.1v)

Will a 22AWG solid wire suffice? PVC insulation? (I guess the breadboard jumper wires are 22AWG itself)

Update:: upon troubleshooting, I found out that one motor was defective as it was throwing red error light on the Sabertooth. The red light apparently means the motor is drawing high current. No wonder it burnt all the wires. I found this out when I tested each motor individually on single channel.

However, this is still a concern because one of motor might fail in operation and could literally burn the robot. Any suggestion/advice would be helpful.
Is there like a current limiting fuse that I can use? Or some super amperage wires that’ll not go up in fumes?

3

Hello @AdzTheDemon,

Sorry for the late reply.

The 22AWG wire can only handle 6.3A so it was normal for the wires to melt down with high current.

But this doesn’t mean that the Sabertooth is the issue, it has over-current protection but this works after 25A so it was normal for the wires to melt down.

You can’t use the jumper wires to connect the Sabertooth to the motors, you can use them to connect to a receiver as shown in this picture below:

image
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As you can see in the picture, the motor wires are different from the normal jump wires.

You can use the 10AWG wire to be on the save side:

Let us know if you need further assistance.

Sincerely,

4

Thank you Ebram. It perfectly makes sense. I will source 10awg to be used on the battery side of connections.
Appreciate your time on this!

One follow-up question I have is, the M+ and M- wires coming from the motor encoder seem to be 22AWG… would that not be a problem? I presume the same current draw will apply to those wires as well?

Regards,

Adarsh.

5

Hello @AdzTheDemon,

Thank you for your reply.

You can use the Kangaroo extension to connect the encoder’s wires directly to it:

image
image1024×1001 223 KB

As you can see in the picture, the motor’s power wires are different from the normal 22AWG encoder wires.

Let us know if you need further assistance.

Sincerely,