Home Forums Everything about the Mini Tricopter Is one ESC broken?

This topic contains 5 replies, has 2 voices, and was last updated by  mioh 1 year, 1 month ago.

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  • #58473

    mioh
    Participant

    Hi all!

    Did my first crash today with the Mini Tricopter. The right motor moved about 25mm along the arm and all four cables going into the right ESC came lose. (Red, black, white and black.) Looks like some components got little bit hot. (See picture taken after repair.)

    Soldered the cables, attached battery and armed the tricopter. Left and tail motor spins OK, but the right does nothing. Well, almost nothing. Then attaching the battery all three motors does “sing” and moves a little bit, but the right motor do not take the last two tones.

    Left and tail = Beep Beep Beep — Beeeeep Beeeeep.
    Right motor = Beep Beep Beep — … nothing.

    The Mini Tricopter was bought 4 June 2016 so I got 30A Little Bee 2-6S Lipo ESC.

    1. Is right ESC broken and need to be replaced?
    2. If it’s broken, is it OK to change only the broken one to an Aikon AK32 35A 6S BLHeli_32 ESC before flying again.
    3. Anything else I should do?

    Before flying this week it was a very long time ago I flew, so I not really updated in the tricopter world. Took for example some time to figuring out how to connect to Cleanflight. Had to see the build video only to remember the name of the program, and then finding out which switch on transmitter doing what. Flew about seven times this week before crashing. (Think I selected wrong flightmode since the tricopter didn’t leveled out after a flip.) Was really happy flying again so this morning I was reading about FPV googles and similar since I remember my FatShark PredatorV2 from 2013 only showing a grainy greyscale image. Now it looks I have to use my money changing ESC instead of buying an Eachine EV800D or similar.

    Off Topic: Rocket Knife on youtube Rocks! 🙂

    #58488

    Kevin_Erik
    Moderator

    Things to inspect.

    Check that the ESC is receiving power (16v) and that the cabling to-from the FC is good. Furthermore check the PWM signal going to the ESC from the FC. You can often use a DMM to check the frequency of a line or in this case your PWM control signal. For example, If your pwm signal is working at 100hz then expect to see something similar on your DMM.

    BLHeli has a software suite that can be used to configure an ESC VIA the FC softserial connection. If you’re unable to connect to a specific ESC but the others connect just fine, you’ve likely a dead ESC.

    Look for loose or damaged components on the ESC. You’ll need a magnifying glass and some alcohol wet-wipes to clean up and inspect properly.

    While its rare, it is possible to break a wire inside of its insulation, especially if its a small wire. To verify, its possible to ohm out a wire from both ends while moving the length of the cable around. Doing this can often show the break as the cable is moved.

    Ohm out your motor. Measure across two of the three legs then move to the next and so on. Your looking for .05 to .1 ohms resistance across each coil. If a winding is damaged then your likely to see a very high reading on one leg while the other “good” legs read low.

    Soldering is important, more than what people often realize. Lumping solder over a connection to attach a wire is likely to cause a cold solder joint that can result in an intermittent connection. (Yeah your soldering looked a bit rough) Furthermore it looked as if one or more components may have been bridged by your solder job. This effectively shorts components which can cause sudden component failure.

    Check your motors for physical damage by opening it to see it the windings, shaft or magnets have been damaged. Some motors use a screw but motors like the older Red-Bottoms RS2205’s use C-Clips. Place the motor inside a zip-lock bag when removing the C-clip to prevent it from flying across the room.

    Try swapping around a suspected bad ESC for a good one from another of the Copters arms. (solder both in) If the problem goes away completely, it’s like a soldering / wiring issue. If the problem follows to the new arm; then your suspect ESC was the problem.

    If you do need to replace annesc, it’s possible that your ESC is no longer carried so replacing one would require the replacement of all three.

    #58493

    mioh
    Participant

    Thank you for helping!

    Ohm out the motor and got 0.5 across each coil. Motor still connected to ESC. Looks OK.

    Ohm out receiving power wires. Looks OK.

    Ohm out PWM signal wires going to the ESC from the FC. Short circuit between white and black wire. Desoldering white PWM signal wire from ESC. Still short circuit between white and black wire.

    Removed the bottom frame plate to look closer if wires damaged. Where wires come out from arm going to ESC, small hole in both receiving power wires black and red. No visable damage to PWM signal wires.

    Desoldering white PWM signal wire from FC. Still short circuit between the two PWM terminals on FC.

    Left and rear PWM terminals measured to about 800-1200 ohm.

    Does this mean something broken on the F3FC frame? 🙁
    Guess I have to take the tricopter fully apart to search for possible problems.

    (Did not have my best soldering moment yesterday, so I agree soldering looked a bit rough.)

    #58495

    Kevin_Erik
    Moderator

    Well did the board receive any physical damage and are all the pads intact?
    Beyond that, try moving that ESC to another pad and do a quick verification of the ESC. (Eliminate possible faults)

    #58496

    Kevin_Erik
    Moderator

    If you suspect the board perform the following.

    1) Disassemble everything.
    2) Use a clean electric toothbrush and Tech-Alcohol (vodka works too) to gently scrub down the board. (IC’s too)
    3) Heat up the board with a blow dryer or heat-gun (low setting) until all of the alcohol is gone.
    3) Check for loose or damaged components.
    4) Reflow all of your pads.

    Reason for this, if your soldering was rushed, it’s possible that you left solder balls all over the place. These scraps of solder can easily short out your board by moving around during handling and or flight. Unfortunately these things are a bit sticky too due to the rosin flux which ends up coating the board. I personally use wet wipes dipped in alcohol to clean my board after any solderwork.

    After all that reattach the ESC / Motor to the pads you suspect to be faulty and power up the motor using Betaflights motors-Tab. This way if your gear is still no working you’ve not wasted a day reassembling everything.

    #58497

    mioh
    Participant

    Will take a close look at board and pads, and try the right ESC on left pads and see what happens. This next week due to some non tricopter plans. Thanks again!

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