Yeah, I know this should be the basic question but I flip the page too fast and skip that chapter.
OK, the situation is the wire getting very hot when motor is running. Basically there are 2 sizes of wire I am using, thin and thick. From the image below the battery wire is thick one and the wire on controller is thinner one. Also, wires from motor are thinner, too and that's why I thought thinner wire might work as well? Now, please notice the wire after the connector from battery become thinner, this is the section getting hot when operation is going.
Do I need to replace the thicker wire in that section?(battery to controller) Or if anyone could please tell me how to pick correct wire for bigger current?
Now I just came up 2nd question. Each motor draws 60A max and the controller could handle 50A per each channel. Does that mean motor won't run up to MAX speed? I know it's not good to reach max speed but just curious.
hardmouse,
I would point you to the following website.
http://www.powerstream.com/Wire_Size.htm
From the looks of it, you are trying to draw a max of 50A through what appears to be 18 or 20 gauge wire. According to the chart I linked to, you should be using 10 gauge.
Cool! This is helpful. Thank
Cool! This is helpful. Thank you!
Wondering if the motor has
Wondering if the motor has 60A when stall and I use 14A motor driver to drive it. Is it gonna damage anything or just not enough current?
You can damage something if
You can damage something if you try to draw more current from it than it is rated to provide.
I would recommend that you install fuses or breakers in-line to protect your electronics. This will protect you under stall conditions.
Also, you need to determine what the current consumption of your motors will be under operational conditions. If your driver provides 14A per motor channel, you should be sure your motors pull less than that while under load.
Motors?
What kind of motors are you using that are drawing 60A at stall?
This is what i use.
INFO:
Nominal Voltage - 12 vdc
RPMs - 96 rpm (no load)
Amps at No load - 3.4
Amps at Stall- 68
Torque (Max) - 325 in-lbs or 36.7 Nm
Weight - 2.7 lbs
I think that’s how I burned
I think that's how I burned the controller. So, according to what you mentioned, should I add the 50A fuse in spot A or spots B1&B2 or C1&C2 ? Correct me if I am wrong, I think C1 and 2 is the place to insert 2 50A fuses or even smaller?
The machine will be too heavy for these motors around 80 pounds, don't you think? I need to reduce the weight otherwise getting more powerful motors and controller is just way to expensive.
I would lose the plastic psu
I would lose the plastic psu connectors and invest in more of those deans plugs(the red ones) that you have in your first image(and slightly in the last). Those plugs have been rock solid for me at least in my rc car days. 10gauge wire should work as well.
Thanks for suggestion. I was
Thanks for suggestion. I was thinking to replace those plastic one with deans plugs on motors too.
Ah yes… I am a bit slow from time to time…
Got it… The tank with the awesome tracks, huge bearings and tons of chains --How the hell did I forget?
I think everyone else pretty much got everything covered but here are a few that I have learned the hard way…
- Take care of your chains!! You are not going to stall when stuck in a corner (the wheels or treads will slip). You are going to stall a motor when you throw a chain. It happens very quick with no warning.
- Clean connections all around. Tighten everything well and keep it tight. Fewer connection total is better.
- “Ramp” everything. Take the time to add gradual speed changes to your code. The amp spikes come A) from start-ups but mostly B) from fwd/rev changes (this “ramping” keeps chains on the sprockets as well)
- FUSES!! Oh, for all that is holy in the world, FUSES!! And for cryin’ out loud, buy spares. When you are coding and testing, you are not going to stop and drive to the store for another fuse, you are going to stick a paperclip in there so you can keep working. Now your robot is on fire. Add a main fuse. Add a main fuse. Buy spare fuses. Buy spare fuses.
- Eliminate 0 and 255 from your code on the RC recieve loop. When you turn a transmitter off, the robot’s serial recieve will “see” either a bunch of 0’s or a bunch of 255’s. This usually throws your robot in full speed forward or full speed reverse. I simply “code-in” to do an all stop when it gets these numbers.
- You would be really surprised to find out what a 30kg mass can do at even as slow as 1/2 meter per second.
Bottom line for me? You have simply put too much work into this project, and it looks so good, there is no reason at all to go cheap on anything, let alone something as important as wiring. Use big wire.
Hi Chris,Thank you for all
Hi Chris,
Thank you for all inputs and tips. I am going to get plenty fuses today. As I post following IG’s reply and according to what I got. Where should I add these fuses and what size should I use? I am thinking to get 50A for each on B points.
Or any better suggestions?
What is the difference
What is the difference between “Maximum amps for chassis wiring” and “Maximum amps for
power transmission” ? Am I right that for the motor power I look at " “Maximum amps for
power transmission” ? What is chassis wiring then?
What motor driver are you
What motor driver are you using? I need a 10A one.
You always need a main one…
The simple theory with fuses is that they only protect things AFTER them so your main big fuse should be as close to the battery as posible. This way, the part of the wire that is unprotected (between batt + and the fuse) will be as short as possible. Next, you may want to run a fuse on one of the wires going to the motors themselves. If you use a fuse lower than the max current the motor driver can put out, you will protect the motor driver --I.e. the fuse will fail before you max-out the driver. I like the glass fuse holders --the ones where the fuse comes out with the cap and the cap is removed with a slight push and a 1/4 turn. The spade ones are just fine too, but they are always a pain to pull out of their holders.
@roboserg
This is the motor driver you need.
IMHO
Chassis wiring is the column you want to use. I pointed this same table out to someone else here once and we decided that chassis wiring is for relatively short distances, a foot or two(30 to 60 cm). We also, then decided that power transmission was related to much longer distances, think on a smaller scale than what the power company uses(power transmisison).
just make sure the fuse is
just make sure the fuse is in between the battery and your circuitry and it shouldn’t matter where you place it. Can the driver handle 50Amps continuous or a spike? If your motors stall at 60 they will blow the fuses every time your system stalls.
Too expensive. You can stack
Too expensive 
I just need a motor driver up to 10A.
The driver’s documented "Out
The driver’s documented “Out of the box, the Sabertooth can supply two DC brushed motors with up to 50A each. Peak currents of 100A per channel are achievable for a few seconds.” So, I guess it could handle it for few seconds. I need to reduce lots of weight on my tank to prevent the stall for sure. Rather blow the fuse than blow this driver. Most expensive part on my tank. Thank you for information 
I just need a motor driver up to 10A. 