Walkera UFO MX400S/QR X400 – ESC Shorting Out Problem

Walkera-UFO-MX400s-QRX400 Quadcopter

 

 

The UFO MX400, MX400S, and QR X400 all use the same ESC
and all have the same ESC shorting out problem.

 

Quick overview of the problem

The ESC shorting out is caused from a motor wire in the motor fixing pipe shorting out on the screw going through it which shorts out the bell of the motor and shorts out the ESC.

The motor wires are in the motor fixing pipe and they are pressed against the screw threads. The vibrations over time are cutting through the motor wire and shorting on the screw which shorts out the ESC. Walkera needs to address this issue.

Walkera made an improved version ESC thinking this was the problem but it is not. I will contact them again.

I have the new version ESC installed and have the motor wires on the outside of the
motor fixing pipes.

I am now recommending to not buy the quad unless Walkera fixes the ESC shorting problem.

See the last post below at the bottom of this page for the latest update.

 

 

Detailed Version

March 29, 2013

I went to bind and fly my QR X400. As soon as I connected the battery to the quad the brushless speed controller went up in smoke!

The quad has been working good until now. It has not been crashed or damaged.

I did some trouble shooting and found that there is a short with one of the motors.
I removed the motor and motor wires and found the short.
The black motor wire insulation was torn 4mm long during factory assembly causing a short and blowing out the brushless speed controller.

The brushless speed controller is very expensive at $106.00 plus shipping.

 

———————————————————————————————————

May 07, 2013
Another Brushless Speed Controller Shorted Out

My new replacement ESC has shorted out which was working great for a while.
This new ESC had very little use on it just like my other ESC had.

I put new motor wires on to replace the bad wires before I installed the new ESC and
checked all the motor wires for any shorts with my Fluke 77 multimeter.

I am now recommending to not buy the quad unless Walkera fixes the ESC shorting problem.

I found out that this is a know issue with the UFO MX400 that has not been fixed and the QR X400 uses the same ESC.
I have also seen many posts on the forums with peoples ESC shorting out new out of the box after a small amount of flights.
I even saw one post where someone had their ESC short out in flight.

Hobbyone is not going to send me a another replacement ESC.
I am looking into putting in a good aftermarket controller board and ESC’s on this quad.

 

———————————————————————————————————

May 14, 2013

New Model Brushless Speed Controller

I was just told that Walkera is making an improved version ESC with better parts for the UFO MX400/QR X400.
This is suppose to fix the ESC shorting out problem.
It is due to be released soon and they will be sending me one. I will post pictures of it when I get it.

 

———————————————————————————————————

June 09, 2013

Here are some more posts I have seen on the ESC shorting out problem.
This is a problem that Walkera didn’t fix with the UFO MX400/MX400S or QR X400.
The UFO MX400/MX400S and QR X400 use the same ESC.
The only difference between the UFO MX400S and QR X400 is a new canopy design.
The motor wires are ran through the motor fixing pipes the same way on both models.

 

  • I have this MX400 and the motor speed control board burned out!. Although this is a new product I have been unable to find anyone with the replacement board in stock and ready to ship. (Walkera UF0-MX400 Brushless speed controller HM-UFO-MX400-Z-23).
  • I personally know 3 people that have had the Speed controller board go out on their MX400s (I am one of them). The board is a expencive one too!. I was wondering if any experts out there could tell me if the MX400s electronics could be completely replaced by another more reliable system?. I don’t know much about this hobby but it would seem to me if you have a frame and 4 motors, you should be able to replace everything else from off the shelf stuff?. (OPINIONS PLEASE?)
  • Post: I got it from http://www.rchelicopterselect.com/sh…licopters.html. I just emailed them, hopefully they will figure it out. Is it normal to be fried without any flight time on it?  Reply: Well not always, mine lasted 2 flights before it did the same thing as yours. If they are paying for the repair you are lucky although you will be out time and postage. Remember, when you get it back in 100% working order SELL IT AS FAST AS YOU CAN!.
  • I have for sale a Walkera UFO MX400 Z 23 Brushless speed controller, this was working fine up to a couple of weeks ago when one motor of the quadcopter suddenly stopped working, looking at the board there appears to be a heat damaged area (top left photo), which I took as the reason for the motor stopping, I replaced the board with a brand new unit, which cost a small fortune, hence the reason for selling this board, it might be an easy fix for someone with the appropriate electrical knowledge.

 

———————————————————————————————————

June 17, 2013

Hobbyone is no longer responding to my emails about this subject.
I have told them people are asking about it and asked if they could check with Walkera again.

There is no ESC to upgrade to that I know of. I was going to run 4 separate ESC’s but I don’t know how to wire it.
The ESC shorting problem is from the motor wire in the motor fixing pipe shorting out on the screw which shorts out to the bell of the motor.
My first short was from a bad wire from the factory and after flying it for some days the wire shifted and shorted.
I replaced the wires with new ones and checked the rest of the wires which I found one had a small cut in it so I replaced it also.
With all the motors wires in perfect shape I flew it again for days then it shorted again. I took out the motor wires and one was cut.
The motor wires are in the motor fixing pipe and they are pressed against the screw threads. The vibrations over time are cutting through the motor wire and shorting on the screw which shorts out the ESC. Walkera needs to address this issue.
They may be thinking if they make the ESC more heavy duty that it can handle the motor wire shorting.

I recommend that once you replace the bad motor wires to run them outside the motor booms.This is what people are doing so the wires don’t short out again inside the motor fixing pipe. I found out about this after my second ESC shorted out.
You can use colored zip ties to secure the motor wires which blend in with the colored heat shrink.
To remove the motor wires you will need to remove two screws. One on each and of the motor fixing pipe. Use a wrench to remove the nuts. I think they are 5/32″.
Once you remove the two screws gently remove the motor wires one at a time.

I have my motor wires ready to zip tie to the booms once I get an ESC.

 

———————————————————————————————————

July 25, 2013

 

I emailed Hobbyone again and got another person than who I have been dealing with before.
This person was very helpful and sent me the improved version ESC the same day.
I installed the ESC and the quad is working well. I have the motor wires on the outside of the
motor fixing pipes.

I posted some pictures of the ESC. The FET’s have different numbers on them than the
other two ESC’s have. So it looks like they changed the FET’s. They also put a lot of solder on the FET pins.

There is no way to tell the original version ESC from the improved version ESC in
the package except that the improved version has a green sticker with a dab of green glue or silicon. The original version ESC has a green sticker with the words FQC on it. The numbers on the package are both the same.

As I posted above the ESC is not the problem so I will send Walkera an email that the ESC shorting out is caused from a motor wire in the motor fixing pipe shorting out on the screw going through it which shorts out the bell of the motor and shorts out the ESC.

 

———————————————————————————————————

August 16, 2013

 

The new version ESC has been working OK but now the Receiver has stopped working.
I took out the Rx and ESC board and bought the KK2.0 Flight Controller Board and other parts.
It is working very well. Here is a link to my review on it. http://www.rcproreviews.com/kk2-0-flight-control-board-v1-6-firmware/

I will no longer use the Walkera Rx or ESC board.

 

———————————————————————————————————

September 6, 2013

I sent Walkera an email and got a response.
I sent them a very detailed report with pictures and video.
They still don’t understand that the motor wires shorting out inside the motor fixing pipe is what is shorting out the ESC.
They need to fix the issue of the motor wires being cut on the sharp screws inside the motor fixing pipe which shorts out the ESC.

Part of what they emailed me.
” our engineers already improved the design.”.

After running the motor wires on the outside of the motor fixing pipes I haven’t had any more shorting out problems so this is what I recommend that you do and now we know that Walkera is not going to do anything more on this issue.

 

 

 

 

 

 

Walkera QR X400 – Motor Wire Short in Motor Fixing Pipe

 

 

 

 

 

 

“My text, pictures and videos are Copyright 2009 – 2017 Tom Zadar”