MJX Bugs 5W flying time problem

K

Kozo

New Member
Hi Guys,

I've a Bugs 5W quadcopter. Its one year old. During the winter it was resting on the shelf. (The battery was charged). When I started to fly again the flight time was approximately 3 minutes. I bought new batteries, but the problem is the same! Any idea? Thanks in advance!
 
Maybe silly question but you make sure the new batteries were fully charged and are they the same exact ones that it came with in the first place?
Also I don't have a bugs quad but does yours have brushed or brushless motors? If brushless the rotor (rotating can part on outside) will have air gaps and can see the coils inside the motor, if a brushed motor typically just shiny silver can on outside of motor that doesn't spin and just the shaft spins. I ask because brushed motors have about a 6 hour runtime life and will start to wear down pretty quick after they have exhausted their lifespan and will get really weak power or short flight times as they die. Brushless motors will last basically forever or until the bearings supporting the shaft wear down at least.
Only other thing to mention is cold batteries won't work as efficiently nor will really hot ones you want them around room temp for ideal operation.
 
Another tip if not flying for a while discharge batteries to about 50%. If stored at 100% they lose life (imagine it is a balloon under pressure or a spring under load).
 
First of all thanks for your reply! :) It's the brushless version and the new batteries were the same as the original. Finally I modified one of the battery frame to be able to connect a standard XT60 connector. I connected a brand new 2 cell same capacity battery and the result was the same. Maybe I didn't store the battery well 'cause it was fully charged, but when I bought the new batteries the flight time was also three minutes.
 
" when I bought the new batteries the flight time was also three minutes. "

Possibility/speculation:
Is it possible your controller app is giving false readings?
Had you tried continue flying the 5W when you got the low battery warning, or did it land automatically?
 
Hmm gotcha yah if changed the connector would maybe double check the solder on that make sure it is a good connection (not a possible cold solder get the whole bullet and wire going into it molten) maybe even over do it, as is you might have a high resistance connection that is bleeding off power as heat. Guess another thing to check is that the motors spin pretty smooth by hand, should feel the "notchiness" from the magnets in there but otherwise should spin smooth and without any grinding noise (funk stuck between the coils and magnets or funk in the bearings from water/mud could reduce efficiency as well, or something else physical like a pretty bent prop). Also flight time can vary a lot depending on how much ascent you're doing or basically how much the throttle is being used to fight wind or climb. I usually get somewhere between 5-8min on my 5" with 4S 1300mAh to 1550mAh batteries (no go pro so my rig is pretty light just a runcam and the essentials :D).
 
Hi, just read your posting on Bugs 5W, sorry for my English, I'm not a native speaker. I do have absolutely the same issue with my 5W. My observation is, that battery warning and finally unconditionally return to home comes at way too high battery voltage. When discharging the used battery, I found in mean more than 1/3 capacity left (e.g. 600mAh). I tried to improve the situation by new battery with 2200mAh but flight time was increased by some minutes only. Does anybody know, how to modify battery warning thresholds in Bugs flightcontroler? Thanks in advance for your support, Arno
 
Hi Despotovdoki, as far as the translation of your Hungarian comment is correct, I understood that you have the same issue, maybe you try to post in english next time. Unfortunately there was no further response at all. During Christmas holiday I got an idea to manipulate the battery sensing, which turned out as impossible since i was not able to identify the battery sense tracks on the controller board without circuit diagram and pcb layout data. So the only change I could imagine is to change thresholds within registers of flightcontroler. But therefore we would definitely need somebody who knows on how to manipulate firmware entries somehow, since I would expect, that FC firmware is secured property of MJX and not an open common flightcontroler software.
 
Unfortunately there was not any response to my issue with BUGS 5W. Are there any suggestions on how to get support in programming of BUGS 5W Flight controler or how to overcome that issue? I would expect, that almost every user of that Quad suffers on that short flighttime problem.
 
There's not really anything you can do because don't have the original source. You could try "bit banging" where you're flipping bits in the firmware randomly (assuming can access said firmware) but you don't know what the expected outcome is really so that's a pretty hopeless effort if can't automate testing of the board. Best bet is toss it and start from scratch IMO... you can replace the FC if you wanted to and keep the frame/motors/props etc. but would need to hook up a new control signal receiver (RX) and get a new TX (basically building from scratch anyway and then using some cheaper frame/motors than you could easily purchase given cost of other components)

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If the FC uses a common MCU like one from ST-Microelectronics (STM32) or Atmel (AVR/AT-MEGA/AT-TINY) then you can typically find the pins used for flashing new programs onto them and with a programmer board (or using an arduino as in circuit serial programmer or ICSP) you could in theory write new firmware to the board but with any FC you buy that is Betaflight compatible it has USB port that lets you do this with no hassle (not to mention all the source code is out on github for you to pull/fork/compile and flash at will... or use the betaflight configurator to downoad already built firmwares and flash to FCs like regular folks).
 
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I have the same problem with my 5W, It will fly for a minute then land, pull the battery out , re initiallise , fly for another minute, it keeps doing this so its not a dead battery, and I can't seem to be able to email BJX RC, someone out there on the InterTube must know how to fix this?
 
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