Beginner questions - WPL C24

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Benno

RC Newbie
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Hi all! My son and I picked up a whole load of parts to build a WPL C24, which has been a great project for him to learn about gearing, drivetrains, and the general mechanics of vehicles. It's a great little kit!

Unfortunately we had to scrounge a lot of the electronics ourselves, and we have been having some major problems getting it working correctly.

Our transmitter is a FS GT2 paired with the FS-GR3E receiver (the included A3 receiver was faulty). We've got a couple of batteries, a generic NIMH pack as well as a 2 cell Turnigy lipo (1,000 mAH, 7.4v). The motor we've fitted is a geared higher power 300 motor which was included (which for now we are just leaving in a single gear, as our transmitter is only 2 channel).
IMG_0119.png
IMG_0117.png



Our problem is finding an ESC that ties the whole lot together properly!! We have gone through 3 or 4 different ones without much success. We started with these generic 30a brushed ones that everyone else seems to be using:
Screenshot 2021-06-10 at 11.43.30.png


We found these drove the front steering OK, but wouldn't transmit power to the motor. It's not a transmitter issue because if you swap out the steering servo lead into channel 2, we could use the throttle trigger to steer the wheels. Very strange. The ESC then rapidly gave up altogether and stopped working completely.

Testing the motor by connecting the battery leads directly to it worked without a problem in both forward and reverse directions. So the motor definitely works.

I wondered if I had a faulty ESC, so ordered a couple of replacements. One didn't work at all, and the other one developed a similar fault. I started to worry that the lipo I'm using delivers too high a current and is burning out the ESC. So I ordered a higher ampage ESC (seen on left, with the original fried cannibalised one on the right).
IMG_0118.png


This did something incredibly weird where it would deliver power intermittently to steering servo with a reeeeeeally long delay (i.e. turn the wheel on the transmitter, wait a second or two, then the servo would move). I noticed the battery was getting really hot so quickly disconnected the whole lot. I'm sure the ESC I'm using now is drawing too much power. Again, the same problem of not being able to deliver any power to the main motor.

I'm very much a novice at all of this, and I'm sure I am making some fundamental mistakes in how I'm putting all of this together. My poor son is getting more and more discouraged - as he has loved building the truck but the problems with the electronics are getting him down.

Can anybody please advise on what I need to get this working correctly? We have been using this video as reference (
) and I can't figure out anything that I'm doing differently (same battery specs, same ESC, same plug positions)...


Any advice would be super appreciated - thank you!
 
Are your escs rated to handle the batteries you have chosen? A 2 cell lipo is actually 8.4volts fully charged... did you calibrate esc to radio(a must)
 
Are your escs rated to handle the batteries you have chosen? A 2 cell lipo is actually 8.4volts fully charged... did you calibrate esc to radio(a must)
Hi TNT - thanks for your reply. I'm not sure exactly sure if the power rating for the ESC is right - the little red ones state they are rated up to 30 amps which seems sufficient, and they are the same item that I've seen recommended on several other discussion forums. The larger one is up to 320 amps (which I'm sure is far too much, but I'm not sure it can draw that much from the battery? As I said - complete beginner!)

I hadn't encountered any references to calibrating the radio to the ESC - how is this done?
 
To calibrate your esc to controller should be a simple task. You can probably find a video on YT that will walk you threw step by step. Or you can Google it. With the name of controller name and esc
 
calibrating should be in owners manual. like said above also with model # of esc and searching should give you a manual dl or you can see correct procedure. 5 cells is 7.5volts while 2 cell is almost a volt more 8.4volts.
 
The fact that the battery is getting hot very quickly and the fact that you keep burning up speed controllers suggests to me you have reversed polarity somewhere. Make sure and go over everything and make sure pos is connected to pos and neg to neg, especially in the receiver. The negative wire needs to face the outside of the receiver and the signal wire goes to the inside. Positive is always the middle pin.

Heres the specs on your very first ESC and its perfectly capable of handling the motor and the batteries you are using. This is another reason why it sounds to me like you have some reversed polarity somewhere. The ESC doesn't really draw power on its own btw. I mean a minimal amount just to power itself on but it doesn't start drawing any kind of significant current until the motor starts drawing it from the ESC. Either way though you should be within spec here with what you are using. Id keep using the LiPo btw, NiXX battery tech is ancient to cavemen by comparison. Oh and another btw, if you do find reversed polarity somewhere then your receiver and battery have possibly been compromised too. If not then let us know and we can try to come up with a new theory :)

Usage:
RC ESC 20A Brush Motor Speed Controller w/ Brake for RC Car Boat Tank

Description:

1pcs 20A brush speed controller.
Function: forward, reverse, brake
working voltage: 3.0V---9.4V.
Diaensions(L*W*H): 35.0*22.0*6.0mm
Current(A): 20A
Driver frequency: 2KHz
Input: Li-Po 2S / Ni-Mh/Ni-cd 4-7cell
Constant current 20A Max 25A< 30s Pulsed 50A< 5s
Brake On / with brake
This ESC can work with 130/180/260/280/380 Brush Motor
Size:20*20 MM

Package Includes:

1*Brush Motor Speed Controller
 
Is there a jumper on the esc that allows you to change from nmhd to lipo ? If it's set to nmhd and your using a lipo this could be a big problem .
 
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