clodbuster Can someone help with an electrical issue?

[BobbyT 21]

Hey all. Thank you for letting me participate. I'm splitting my free time for hobbies to include building RC trucks. I built my 1st Clodbuster 20 years ago and it was great fun. Still drive it in fact. I got the urge to build another, only this time I'm building it highly modified. I'm using all new parts. I started with the Super Clodbuster Gray Edition. The parts from the kit I'm using are the gearboxes and motors, tires, body, electrics tray and ESC. Everything else is aftermarket. I want the twin steer function, I'm using Arch Fabrication servo mounts front and back with Hitec HS-645MG servos. I have the mechanical work nearly finished and now I want to get the electrics resolved then neaten everything up. This is not a for competition build. I want it to look cool and work right. I purchased a Spektrum SLT3 3 channel transmitter with a SR315 receiver. The ESC is the Clod kit included THW-880-Dual-Brushed-RTR. I installed a Y cable to connect the steering servos together to the receiver. I linked the transmitter to the receiver, tried the steering, and it crab steers. Not what I want. I want the steering to be as a stock clod. I figured I need to reverse the rotation of one servo so I have a cable coming for that. Now my problem is the motors don't run. They are wired to the ESC correctly. When I power it up, turn the switch on, The ESC leds flash red twice then it beeps. I pull the trigger and nothing happens. Any help on this would sure be appreciated. Thanks all. BobbyT  

[BobbyT 21]

My current build. 

[droidy 91]

You can't swap the polarity of a servo to reverse it (like you can with a motor) because the timing of the signal over the signal wire controls angle, not the +/- polarity.

Look for a servo reversing cable - they have a microchip that will alter the signal and "reverse" it.

Some transmitter/receivers can take the single steering input signal and do "4ws mixing" to provide two output channels but Spektrum SLT3 doesn't mention that capability so I assume it can't.

[BobbyT 21]

Thank you droidy. I ordered the reversing cable yesterday. Be here today. Now to get power to the motors. A different forum suggested recalibrating the ESC. Any thoughts on my motor issue?

[droidy 91]

1 hour ago, BobbyT said:

motor issue?

Step 1: read your receiver manual.

Step 2: ignore it because it's wrong!!!

Step 3: plug your ESC into THR (second from the top - I mean I guess! Someone with the radio might clarify but common sense dictates THR is the correct one).

Steering is channel 1 and throttle is channel 2, and throttle channel 2 should go to the ESC. Make sure the plug is around the right way, too, but it must be or else you wouldn't have power to make your servos work.)

(Wow, that's the worst possible receiver design. Bind should be furthest from steering so you can naturally count channels "1, 2, 3, bind" from one side to narrow down the logical possibilities).

It sounds like your problem is that the ESC can't calibrate itself. It looks for your neutral throttle signal and tries to figure out forward/reverse/min/max from that. The ESC manual should describe it in the Troubleshooting section.

It won't work if the ESC is plugged into a non-throttle channel.

You also need to make sure that your throttle trim and throttle reverse are set to neutral/default. As per the manual - "TH" at zero/neutral, "TH/LIM" at 100 and "TH/R" at normal/not reversed (whatever that means, can't tell from the drawing in the manual).

[BobbyT 21]

Thanks very much droidy. I'm going to follow your suggestions. I need to take care of some chores around the home today, so I'll get back to this later this afternoon. Thanks again for your help. I wanted to look at the image you posted, but I got the 404 error message. 

[droidy 91]

I re-uploaded the image. It just pointed out that the labels in the manual contradict the sticker on the receiver! So if you followed the manual labels you might have it plugged in wrong. I think the sticker on the receiver is correct (because that would make sense) but I'm guessing.

[BobbyT 21]

I just did as you said droidy. Success! The motors both run. I had to switch motor wires around on the rear axle for it to match rotation of the front. Got forward but no reverse. Maybe I need to change to a different radio and receiver? 

[droidy 91]

Woohoo!

I'm sure your radio and receiver are functionally just fine. Try fiddling with TH - you want it in the middle/neutral. You probably need to turn ESC off and on after each change.

If that fails post some pics. Good luck!

[BobbyT 21]

Thanks very much droidy. Your help has made today better.