Gruber
HobbyMasters
M.L. Toys
KidsWheels
Gruber
HobbyMasters
M.L. Toys
KidsWheels
HobbyMasters M.L. Toys
Gruber
KidsWheels
Electronic Scooter Controllers have become a popular addition to our vehicles. Ask specific questions about ESCs here!

***WARNING*** this section is for ADVANCED MODDERS. if you try anything in this section you NEED to expect minor issues with the build up to and including complete FAILURE of EVERYTHING in your freshly built BPRO.

Have fun ;-) :-)
By michael76
#135295
Running a 36v esc conversion on a stock 24v peg ride on. Been burning through motors. My son rides in the grass on a slight incline. Could the motors be burning up under the extra load? Should I upgrade the motors to 36v, drop down to a 24v controller and overvolt at 36, or drop down to a 24v controller at 24?

Thanks
User avatar
By toycrusher
#135301
What is the watt rating of your controller?
User avatar
By toycrusher
#135311
Might try running dual controllers, one per motor. Just splice the pedal wires and run them to both controllers.
By michael76
#135318
That's beyond my capabilities! Would it be easier to drop to 24v controller with banebots? Would I lose much speed and torque?
User avatar
By toycrusher
#135323
I have a couple rides running the newer 350 w peg motors at 36v with no problem. I really don't have any inclines though.

A dual controller setup is really easy. Are you using relays for forward and reverse or using the stock shift switch?
By michael76
#135328
I'm using relays. I'm ignorant, but could you explain how running dual controllers would reduce the likelihood of burning up motors? Wouldn't they be pulling the same power under load. Right now they aren't even able to be touched because of heat. Always thought more voltage equals more heat.

Thanks
User avatar
By toycrusher
#135337
Theory and reality are often at odds. Motors can burn up if they stall due to insufficient amperage. Dual controllers in theory supply more amperage making the motors happier. That's the theory anyway :lol:
By michael76
#135349
Ok. I'm intrigued. How do I do it? I have an extra one I can use. Please provide instructions for a non-technical person.

Appreciate your help
User avatar
By toycrusher
#135351
This is how I did it on my superpower. It's basically duplicate relay setups, one per motor. I haven't tried it yet, but I have a feeling you wouldn't even need the duplicate relays, you could probably just combine the motor output wires leaving the two ESCs and keep your existing relay setup (provided they are 30+ amp capable).

download/file.php?id=22165&mode=view

Image
Last edited by toycrusher on Sat Sep 26, 2015 3:35 pm, edited 1 time in total.
By michael76
#135354
So, if my relays are capable, I would just tap the motor and power wires for the second controller? No other connectors?
User avatar
By toycrusher
#135355
Basically. Motor, power, key, and throttle.
User avatar
By toycrusher
#135361
40 amp would probably be better. What gauge wire are you running?
User avatar
By toycrusher
#135365
As I mentioned, I haven't tried parallel speed controllers where do you think an issue might lay?
User avatar
By sall
#135369
I don't know 100% that it won't work. If you read about how the controllers function in the mod thread I posted...

"Basically YK31C is PWM controller for brushed DC motor with low voltage protection and current feedback limit.Core is triangular generator, which is comb ined with throttle level into PWM modulation. To be able to control the current flowing through the motor, there is pair of shunts (looking as U bent wire). In fact shunt isnt just wire. It has some amount of very small resistance, but together with high current it will generate some voltage on it. Ohm law says voltage = current * resistance. So the higher resistance or current is, more voltage is gathered. This voltage is fed into comparator which compares its value with preset value. If its higher, it will kill the output. This way controller adjust the output current."


I would assume it would just confuse the controllers and kill the output? Out of curiousity I posted in a RC forum I am active in to hear an opinion on the subject and will report back.
Last edited by sall on Sun Sep 27, 2015 12:38 pm, edited 1 time in total.
User avatar
By toycrusher
#135371
Sounds good, keep us updated.
User avatar
By sall
#135384
The consensus is paralleling two ESC outputs equals fried ESCs. You can try it though if you want. It's a $30 gamble that the house likely wins. Relays are cheaper!
By emolatur
#136635
I build controllers -- as in, I buy blank circuit board, ICs, resistors, capacitors, diodes, and mosfets, and solder them into submission.

I can't necessarily speak for every controller design out there, but for mine ( http://www.glytch.net/~emolatur/electro ... esc24v.pdf ) you won't do any damage by attaching the outputs in parallel.

However, a PWM motor controller is a switching device -- it works by turning the motor on/off at a high speed (440Hz in the one I linked, 2.5kHz in the latest, higher-power version I'm working on) -- the problem with getting them to switch simultaneously. Just tying the throttle signals ("CONTROL_IN" in the diagram) together won't do it. If controller A and controller B are both at 50%, that does mean that each controller will turn the output "on" for 50% of the time... however, there's nothing enforcing that it has to be the same 50%. Controller A might turn the power on for half of the time and then controller B might turn it on for the other half, resulting in an output that is on all of the time -- 100% output. 0% is relatively guaranteed to be 0% (if nothing is broken) and 100% is relatively guaranteed to be 100% (same conditions) but all positions in between could very well be more than what you expect them to be.

If you're going to try paralleling controllers, and you expect them to behave predictably, keep the outputs seperate.

The other potential quirk is related to the current limit function. Everything has some tolerance - very few things are exact. Each controller I build ends up with a slightly different value shunt resistor. One adjusts the ratio of R12 and R13 to set what current the output is limited to. At takeoff, when the current draw is highest (or if you're going uphill), one controller might output slightly higher current than the other... so your vehicle might tend to steer left or right at that point. It is likely that any difference would be very tiny, but it's still food for thought - especially if you're ever going to try two different model controllers.
User avatar
By toycrusher
#136638
Thanks for the input. I've been finding that with the dual controller setup (outputs separate), when trying to climb something, only one side gets going, usually ending up slipping while the other doesn't move. This puts a lot of strain on the gearbox.

If it's a flatter start both sides kick in and you don't notice any pull. It just seems one controller pushes more amps on startup than the other
Aftershock motor

Looking for an aftershock motor. Doesn't have to […]

Hey guys, to start off, first-time poster and modd[…]

3a motors and gearbox

I'm looking to turn a lil jeep into 2wd and need a[…]

Can't access FAQ's

He's NOT alone! Surfing through, I've had a horrib[…]

HobbyMasters