BEWARE Tarot ZYX problem in 600 tail (HOT SERVO)

[utrinque]

I am very happy with ZYX performance in 450 PRO TT FBL.

Problems started with my T-Rex 600e.

Mi Digital High Voltage Metal Gear Servo 8.40kg / 0.03 / 61g burned during the flight due to overheat.

I have changed setup from HV 7.4V (2S lipo) back to 5.8V (Align BEC) but Savox SH-1290 at 333Hz and even with 250Hz setting is geting hot too.

I have found posts regarding tail servo overheating with ZYX. One guy described heli with BeastX in which he removed BeastX and installed ZYX. With ZYX tail servo started to get hot while with BeastX it was cool.

Some guy measured real timings:
http://www.rcgroups.com/forums/showt...12179&page=251

Tail Cyclic
analog 1520uS 71Hz analog 1520uS 71Hz
digital 1520uS 214Hz analog 1520uS 71Hz
digital 1520uS 333Hz digital 1520uS 111Hz
digital 760uS 400Hz digital 1520uS 133Hz
digital 760uS 214Hz analog 1520uS 71Hz
digital 960uS 333Hz digital 1520uS 111Hz

In ZYX manual:
Yellow ,1 flash:All the tail and cyclic servos are 1520us analog. *
Yellow ,2 flashes:Tail servo is 1520us digital, cyclic servos are 1520us analog.
Yellow ,3 flashes:Tail servo is 1520us digital, cyclic servos are 1520us digital.
Yellow ,4 flashes:Tail servo is 760us digital, cyclic servos are 1520us analog.
Yellow ,5 flashes:Tail servo is 760us digital, cyclic servos are 1520us digital.
Yellow ,6 flashes:Tail servo is 960us digital, cyclic servos are 1520us digital.

In ZYX programmer manual:
“1520us 71 Hz ”:All servos are 1520us analogs
“1520us 250Hz 1520us”:Tail servo is 1520us digital, swashplate servos are are 1520us analogs.
“1520us 333Hz”:Tail servo is 1520us digital, swashplate servos are 1520us digitals.
“760us 250 Hz”:Tail servo is 760us digital, swashplate servos are 1520us analogs.
“760us 400Hz”:Tail servo is 760us digital, swashplate servos are 1520us digital analogs.
“960us 333Hz”:Tail servo is 960us digital, swashplate servos are 1520us digital analogs.

Definitely something is wrong with ZYX working with big helis tail servos.

- In BeastX us and Hz paarmeters can be set freely for tail and cyclics in ZYX there are only 6 combinations
- measured values are different than in manual
- there are many pilots reporting tail servo overheating
- "digital analogs" seems a typo in programmers manual

I will probably buy BeastX for 600e. I was enthusiastic after converting 450 to FBL but in my case I do not want to ruin 600. After crash I was blaming HK tail servo... Probably I was wrong. ZYX seems guilty in this case.

http://www.helifreak.com/showthread.php?t=431456

Finally I settled down with 250Hz setting and 5.8V from BEC and Seavox servo on tail gets warm after flight not hot. Yestrday wind was stronger and I did not hide the model in the shadow after flights... It can matter. It is around 30 deg Centigrade (86 F) here.

[Dr. M]

You know, I've been noticing the mks ds760 I run on my Protos tail get significantly warmer than the mks ds9670 I run on the 450, while doing the same type of flying with really similar setups on the gyros. I really wonder why would the ZYX overheat the tail servo on bigger birds...

[LawnDartHeli]

I killed a Hitec 5084 on my 400 the other day. I use the Cx unit on both my 450 & 400 with identical tail setups. I run analog cyclics on the 400...digital on my 450. I run option 2 in the menu (1520us dig tail/1520us anlg cyclic) I just changed the servo out today and noticed it gets warm just sitting.

sent from my phone using circus midgets

[utrinque]

So I moved back to 5.8V setup. I use Savox Savox SH-1290 (same as Align 650) on tail. It is warm but not hot after flight when I set ZYX to 250Hz. HV setvos on cyclics Power HD1209 are cold after flight in this case. I had to decrease gains on cyclics. Now it is OK.

Unfortunatelly I crashed probably due to RJX FBL head malfunction. It seems I lost head arm ball during the flight. To little Loctite I suppose. I do not blame RJX.

I lost blades, mainshaft, spindle, tail tube, tt, main gear, and front tail gears, servo case suffered a little.

Heli is almost rebuilt.

By the way RJX FBL carbon blades are much better than 3D PRO blades.

[mayday1]

I think I was the guy who complained of hot rudder servo (hsg-5084mg) after swapping in a tarot-zyxs
for a beastX.

My rudder servo went intermittent only after a couple of flights, so I sent it back to Hitec.
Hitec sent me a new servo a couple weeks ago and I finally got around to flying it this morning.

Once again, after 2mins of flying the rudder servo got really hot (almost too hot to touch), so
I packed up and didn't fly any more.

My setup is a copterx250 with analog cyclic (hitec hs65mg) and hsg5084mg in the tail, tarot-zyxs
set to soft3D. BEC is 5.5V (measured when idle with a volt meter). This is running v3.5 firmware
I loaded last night. I'll probably re-install the beastX and give up on this tarot.

Will report if the rudder servo is still hot after switch back to beastX.

My suspicion is that the tarot must be constantly wiggling the tail servo a tiny amount in flight.
I don't see how else it can heat up a servo like that, the frame rate is set to 221Hz (lower than
333Hz used when I was using a beastX).

[Dr. M]

Originally Posted by mayday1

I think I was the guy who complained of hot rudder servo (hsg-5084mg) after swapping in a tarot-zyxs
for a beastX.

My rudder servo went intermittent only after a couple of flights, so I sent it back to Hitec.
Hitec sent me a new servo a couple weeks ago and I finally got around to flying it this morning.

Once again, after 2mins of flying the rudder servo got really hot (almost too hot to touch), so
I packed up and didn't fly any more.

My setup is a copterx250 with analog cyclic (hitec hs65mg) and hsg5084mg in the tail, tarot-zyxs
set to soft3D. BEC is 5.5V (measured when idle with a volt meter). This is running v3.5 firmware
I loaded last night. I'll probably re-install the beastX and give up on this tarot.

Will report if the rudder servo is still hot after switch back to beastX.

My suspicion is that the tarot must be constantly wiggling the tail servo a tiny amount in flight.
I don't see how else it can heat up a servo like that, the frame rate is set to 221Hz (lower than
333Hz used when I was using a beastX).

I've noticed that decreasing the 'deadband gyro' seems to keep the tail servo cooler. I used to fly with this deadband at 4 on the tail and I was not comfortable with how hot the tail servo went, so I dropped it to 2 and now the tail servo is noticeably cooler.

Go figure, it's backwards from what I'd expect, but I think it's worth a try fiddling with your DB and see if changin it up or down makes a difference. It may be that you need to match the DB setting on the gyro with the actual DB of the servo for best results.

[mayday1]

Dr M,

do you mean the RC deadband or the gyro deadband? I don't know the difference, but I think I
have my gyro deadband set to 4 for the tail servo. I was thinking about increasing the number,
but if decreasing it works for you I may try that too.

thanks

[Dr. M]

gyro deadband is what I meant - this affects the communications between the gyro and servo. You could try going higher and lower to see which one works the best. If you go too high you'll know immediately, because your tail will start randomly hunting and drifting.

RC deadband affects stick behavior - the gyro will ignore small inputs around center stick, proportional to how high you've set this parameter.