Electrical issues with new xl rtr
 

Hello everyone, I've been searching the boards for a while now and I couldn't find the exact issue I was looking to resolve. After my friend saw my recently finished xl kit, he ran out to our LHS to get an rtr. We went over the thing and checked all the screws and links, all okay... Once he fired the thing up on 4s, the less than adequate servo made itself known. It barely moves the wheels at a dead stop. Fine, no biggie. He drove for a bit and we started noticing a stutter. This only happened twice. Complete loss of throttle and steering, and glitching and clicking at the motor. He wanted a new servo so after changing that to a fairly modest 220 oz/in, the problem is even worse. Is this problem related to the voltage coming off the esc being too low? I checked the esc with my castle link system and there didn't seem to be an option for upping the bec voltage like there is with other systems. My friend is going to be contacting Axial for sure, I was just looking for an answer 'cause I'm stumped!

Re: Electrical issues with new xl rtr
 

Re bind the reciever to the transmitter. Mine did this when it was new also.

Re: Electrical issues with new xl rtr
 

Also look at the connector going into the ESC from the receiver. Mine is an RTR and the connection doesn't snap in, it more like just sits on the pins. This gave me some fits to figure it out.

Re: Electrical issues with new xl rtr
 

I did try the re bind with the original tx and another that I had from another rtr. Same result... On initial start up, I was turning the wheels lock to lock. After doing that 3 times the steering servo slowed right down and the problem began. No throttle/steering and glitching. As far as the wiring to the esc goes, I did not check the connector at the esc itself so I'll have to check that next.

Re: Electrical issues with new xl rtr
 

Install an external BEC for your larger servo. 220 isn't the best for this rig, something over 350 is more in the range.

The stock RTR axial esc doesn't have an option to change the internal BEC voltage. I think it's set at 6v but only 4 or 5 amps.

Stock servo is severely under powered and the bigger servo will pull too much amperage for the stock BEC. What a mess....

Re: Electrical issues with new xl rtr
 

Thanks for the info redsawacs. I had a feeling about the bec voltage being low, that's why I recommended the lower torque servo to my friend. I was just hoping to not have to explain to my buddy that the esc on his $700 investment isn't so great.

My friend just got off the phone with axial and they are sending a new receiver... If that doesn't work I guess I'll have to get the outboard bec. That is a poor design choice to have the voltage locked at 6.

Re: Electrical issues with new xl rtr
 

They knew if they installed a larger servo they would need a bigger BEC. That's up to the customer since its a "custom" addition......

Either way, 25$ should help with the castle BEC but I still think it was a bad idea to go modest on the servo.

Re: Electrical issues with new xl rtr
 

Got the new bec installed and it did fix the issue with the brownout condition. However, the speed control is cutting out during full acceleration and braking... I'm thinking the speed control might be shot. Time to make another call to Axial!

Re: Electrical issues with new xl rtr
 

Did you install the new receiver yet? A bad receiver will do all sorts of nasty things. If you have a spare radio you can put in to test, that can rule out radio issues.

Re: Electrical issues with new xl rtr
 

Okay. Final update.

Yes redsawacs I did try a different rx to no avail. :x So my buddy went out and bought a brand new castle monster 2 today and... Perfect! No more issues. Now to get Axial to send a new esc to replace the defective one. Always nice to have a back up I suppose.

Thanks for all the help!