Trex 250 Tail Servo Problems

[Freakmode]

Hi

Almost finished building a Trex 250 in my spare time as the TV is so crap.

I am running a DS 420 off a GY401. When i plug in the 420 all works fine for a couple of minutes but then the ESC gets red hot, if I take of the tail servo it stays cool.

Have I done something wrong or could the 420 be faulty? Should I use something better than a 420?

[ROCKET RONNIE]

hello mate, not saying i no a lot but does it get hot with just the servo connected only, no rod tail ect, if not then it could be binding ??????????? like i said im just having a guess, good luck

[Freakmode]

I did check that just and yes it still gets red hot with the push rod removed.

[coolice]

Hey.

There are a couple of things to try first before we go any further;

1. Is the GY401 set to Digital Servo (DS) mode using the dip switch? If so try it with it off as I have heard this setting on some servos, even though digital is not liked by all makers servos.

2. The ESC, have you set the BEC output to no more than 5.5 volts? All new 250 kits in the uk go out with a sticker advising the user to set the ESC accordingly, as with settings above 5.5 volts the tail servo burns up quite quickly.

On the other hand I have read of the odd 420 doing this out of the box due to it being faulty, also worth remembering if the above doesn't fix the heating up issues.
.

[Freakmode]

OK made no difference with the dip set to DS off - still got hot.

Could you tell me how I drop the ESC to 5.5v or how to check what it is currently set to?

Thanks

[serpent887]

Yes been there with the 250, make sure you carefully adjust the endpoints (of the gyro not the radio) otherwise the servo will burn up. It cost me three tail servos before noticing this

Hope it helps

[chris jones2.4]

Hey.

On the other hand I have read of the odd 420 doing this out of the box due to it being faulty
.

agreed, loads of em hav burnt out

[coolice]

OK made no difference with the dip set to DS off - still got hot.

Could you tell me how I drop the ESC to 5.5v or how to check what it is currently set to?

Thanks

Hey.

Ok, DS mode made no difference so we'll try the voltage next.

Here is the manual for the Trex 250;

http://www.google.co.uk/url?sa=t&sou...P5snSNM1Ha566g

If you go to page 24 you will see instructions on how to enter the ESC's setup mode, then a little lower down a settings table detailing what parameter corrisponds to what set of beeps from the ESC.

It's quite simple, I'd suggest removing your main blades from the model to be safe first, but before you power up the model set the transmitter stick to full power. (If you have throttle curves set in normal mode, make a note of these and revert the throttle curve to a standard linear line 0 ~ 50 ~ 100% to allow the setup to work properly).

Very basically, after you have turned the model on with the transmitter throttle stick at full power, the ESC will give a series of beeps before settling down into a pattern of single beeps, then 2 beeps, 3 beeps, etc. which relate to a setup step in the table shown.
It is during these beeps that the transmitter stick is moved to a position which corresponds to a setup parameter required from the settings table.

Let us know how you get on, but worst case scenario is you have a duff servo.
.

[coolice]

agreed, loads of em hav burnt out

Hey.

Yes, mine was working but I swapped it out pretty quickly for a better servo. In the end I fitted an Align DS520 to my 250, which while a little big worked very well.
A friend had one go down in flight which was a shame as till that point it was working well.
.

[chris jones2.4]

hey ian, ive fitted the jr 3500g, works brilliantly, bit big nd a little bit overkill though.

[millerman]

i think all have miss read he said the ESC got hot not the servo !!!!! then the tail servo stop working and when unpluged the ESC cools down

answers on a postcard

[chris jones2.4]

my mate had the exact same problem, it was the servo, taking to much current and overheating his esc

[coolice]

hey ian, ive fitted the jr 3500g, works brilliantly, bit big nd a little bit overkill though.

Hi Chris.

Yeah going by size of servo to model it is kind of overkill, but this size of servo works well doesn't it on the 250 as the tail rotor is quite powerful for such a small model. Hence it needs a torque'y yet quick servo to work it.

I started out with a JR 380G on mine before reaching it's limits and fitting the DS520 which worked very well for me. I was using the stock Align GP750 gyro.
.

[coolice]

i think all have miss read he said the ESC got hot not the servo !!!!! then the tail servo stop working and when unpluged the ESC cools down

answers on a postcard

Hey.

No, not misread in the slightest mate.
Chris is spot on with his answer there have been many with the same issue of while the tail servo is connected the ESC, which we know to be the BEC part of it, is heating up. Remove the tail servo from the gyro, which has been done here and the ESC runs cool again.
There s something wrong internal with the tail servo which is shorting the BEC's power supply to the model, hence why it's getting hot and if not fixed will kill the ESC.

Do a google search and/or pop over to HF as from memory there is a lot on this topic there.

[millerman]

Hey.

No, not misread in the slightest mate.
Chris is spot on with his answer there have been many with the same issue of while the tail servo is connected the ESC, which we know to be the BEC part of it, is heating up. Remove the tail servo from the gyro, which has been done here and the ESC runs cool again.
There s something wrong internal with the tail servo which is shorting the BEC's power supply to the model, hence why it's getting hot and if not fixed will kill the ESC.

Do a google search and/or pop over to HF as from memory there is a lot on this topic there.

Stand corrected ;(




Sent from my iPhone using Tapatalk