BLX185 and Mojave Questions

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KingKeif

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Location
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Arrma RC's
  1. Mojave
  2. Outcast 8s
Hello Everyone,

First time posting anything about RC since being in the hobby since 2015. I am just now learning the details of the electronics since owning my V1 Mojave. I will try to be detailed and brief. Apologies if a thread was already created about this.

The Questions:
  • Has anyone with a BLX185 w/ fried caps bypassed the caps with a external BEC (I would remove the positive wire from the esc to transmitter)?
  • Would doing so cause other problems within the ESC or other components in my system?
  • Can I use the vxl-8s esc (found one cheap) with the BLX 2050kv motor if I only use 6s and change the connectors? (Looking for longevity)
  • Would the Firma 150a esc from the v2 work with the BLX 2050kv motor? Its just under $80 on Jenny's RC; I see it has the extra caps and I assume that was the upgrade to the BLX185 (besides the smart capabilities and options).
  • Since the BLX and Firma have HW components, can I expect the same build quality out of a Max 6 combo?(Hopefully Not)
Set up:
All Stock Mojave V1 except for Flysky GT5 Transmitter w/ FS-BS6 Receiver, a Savox SW-1210SG servo, and a custom made vented tub much like the ones people are using from RC Tubz.

What happened:
I was driving the Mojave in a field near my house when the car suddenly stopped. It lost all throttle and steering. The esc was blinking red so I assumed it was thermals as I was only driving it for about 10 mins. I let it cool down for about 15 mins but it did not run. So I cleaned it up and brought it in to see what happened. I found the Receiver was dead; this was my second receiver that died within a year so I assumed it had gotten wet like my first one that died. I had 3 other receivers to test (details ahead).

Test:
  • I have a fully functioning ERevo v1 with the mxl-6s castle system (which btw is still going strong 5 years later). Decided to use this as a testing rig.
  • Already knew the receiver was dead because it did not light up and had a burnt smell
  • Hooked up the Servo to the ERevo and it did not have any response. The wires where ripped near the rubber grommet(figured my fault how I removed it). Repaired the wires before the testing.
  • Thinking the servo caused a short, I put a older Traxxas receiver(used because I was willing to sacrifice it) on the BLX185 without a servo connected. Popped and smoked as soon as I turned it on.
  • 2 receivers left
  • Thinking it was because it was an old Traxxas receiver I hooked up the stock STX2 receiver. Popped and smoked
  • 1 receiver left
  • I checked the motor and the back had gotten loose so I took it apart and checked all of the bearings, Looked good so reassembled and set to the side no longer connected to esc
  • hooked the esc up with only 1 3s battery. Didn't know if it was enough to power it but it did power up
  • I connected the esc only (still only on 3s power) to my Traxxas receiver out of my ERevo and everything powered up and I did not lose power to the receiver.
  • Tried to reprogram the esc but it would not allow me to go through any of the options or set the throttle, brake, neutral on transmitter
  • It would go into programing mode but would not have the green light to tell me what category I was choosing
  • Dumb in Hindsight (I am just trying to figure it out), but thinking it was because it was only on 3s I connected it to 6s (again only esc and receiver). Turned it on and immediately Pop and Smoke. No More receivers
  • I know its not the battery's because I used two sets of HRB Batteries that I tested on my charger with all 3 cells being balanced at 4.2v. They also work well on ERevo.

Conclusion:
I came to the conclusion that the Internal BEC is fried. Unless not being able to reprogram the ESC on 3s is an indicator of something else(I'm no expert). Even though I really don't want to spend the money, I have decided to upgrade the electronics rather than have a Mojave paperweight.
  • Max 6 with 1650kv motor 20t pinion
  • power hobby cap pack
  • castle programable external BEC
  • large heat sinks/powerful fans for esc and motor w/separate battery pack
  • new fs-bs6 receiver in a donated Traxxas water proof receiver box from my Nitro Revo
  • a brushless digital servo (don't know which one yet)
  • taller metal servo mount, or spacers
I know this setup is considered unnecessary overkill based upon what I have read from other people but I want reliability above all. None of us should have to worry about our expensive electronics dying because of voltage changes or an unexpected short somewhere in the system. However, before I spend more money on an already $600+ vehicle; I wanted to see if I could simply salvage what I already have. Thank you for taking the time to read this thread, answer the questions, and provide any feedback to anything I may have overlooked. If you have any questions about anything I have tried I will do my best to answer them.
 
Welcome to AF.
I will start by pointing out some misconceptions above. It may help. And others may chime in with their ideas.
Internal caps cannot be by bypassed. They are embedded components of the ESC board. You can add a cap pack soldered within one inch of the Batt leads. Polarity must be correct or you will pop/ fry the caps in a Milisecond. I think you are complicating things more than they need to be. Your diagnosis skillset is pretty much there. Eliminating what components are good or questionable. etc. Have the embedded caps popped at the top? Just a tell tale sign one or more of of them is fried. BEC is probaably bricked.
An external BEC should remain out of your equation. At least till you get a basic set up running fine. Overkill anyway IMHO. As you eluded to.
A flashing Red light when the BLX185 is first powered on and remains is a fault code. An ESC failure of some type. A thermal Cutoff light will always be GREEN not Red. The BLX185 will work just fine with 3s, 4s or 6s. No issue.
The BLX2050 will work with 3s,4s,6s and depending on your gearing even on 8s. Motor fan being manadatory and motor is in top running condition. (w/8s ESC) FWIW.
A 35kg servos is at least a minimum. Shim your SS hub while you are at it. V1 Mojo has a weakish spring. Like my V1 Mojo.
Brushless or Coreless digital servo, doesn't really matter. It's your wallet. I use AMZ DS3235's. Tried many name brands. I use these now on most of my Bashers.
I'll let others chime in.
Good luck.
 
Welcome to the forum first off. Yes you can use the Spektrum 150a esc as that's what the new v5 6s rigs and v2 Mojave run stock now but I'd suggest something else as it is known to have issues and even lots of ESC fires lately. Also the vxl would work and the HW Max6. The ESC will not harm anything unless you run 8s and even then will just have to be really careful running the 2050kv on 8s to not burn it up. If you keep having receivers crap out it may be your servo is bad and browning them out. I'd suggest taking some time and browse through some Mojave build threads for ideas and to see what others are running and work well with the Mojave. Again welcome to the forum!
 
Thank you both for your welcome and responses.

A flashing Red light when the BLX185 is first powered on and remains is a fault code. An ESC failure of some type. A thermal Cutoff light will always be GREEN not Red. The BLX185 will work just fine with 3s, 4s or 6s. No issue.

Then my servo must have been causing the problem. I agree with you that the BEC is probably bricked. This is one of the reasons why I wanted the external BEC I assumed that the Savox Servo I had was trying to draw more than the 6v the BEC wanted it to have. I figured a $20 BEC is a better sacrifice than another ESC.

I appreciate the Tip regarding the SS and the servo recommendation. It's a great price so I will try it out with whatever esc I decide to go with.

Thanks again. I will post photos whenever I am satisfied with my build.
 
Flashing red light can also be no communication with the transmitter so may try to recalibrate your transmitter also.
 
Thank you both for your welcome and responses.

A flashing Red light when the BLX185 is first powered on and remains is a fault code. An ESC failure of some type. A thermal Cutoff light will always be GREEN not Red. The BLX185 will work just fine with 3s, 4s or 6s. No issue.

Then my servo must have been causing the problem. I agree with you that the BEC is probably bricked. This is one of the reasons why I wanted the external BEC I assumed that the Savox Servo I had was trying to draw more than the 6v the BEC wanted it to have. I figured a $20 BEC is a better sacrifice than another ESC.

I appreciate the Tip regarding the SS and the servo recommendation. It's a great price so I will try it out with whatever esc I decide to go with.

Thanks again. I will post photos whenever I am satisfied with my build.
Some Savox servos are known amp hogs. Can't rule that out.(y) I know my 1210's are amp hogs. And far from my favorite Savox. Have 2 of them. Noisy as heck, sing loud struggling to center. Both that way new out the box. I rather pay $33. for a DS3235 as of late. Cheap enough to have spares around. And none have failed me going on 2 years now. 5 of them. I already got my moneys worth. Servos are consumables in RC. Especially with bashing.
Good luck.:cool:
 
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