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Wyno · 10-25-2016, 03:00 PM

Well, I was on flight 104 today and I noticed the last couple flights that my OS105hzr was making a weird sound, it kept revving up and down really loud a couple times each flight. It sounded like you was revving up a sports car. My last flight it got really bad so I hit throttle cut and landed. I took the canopy off and the throttle servo had no power to it, all the other servos were working perfectly. I touched the servo wire and the power came back on. I played with the wire for a few minutes after and it never once lost power. So idiot me decided to fire it up again and burn the half tank of fuel out. I fired it up and started to increase throttle stick and the heli began revving up on the ground and stuttering really bad so I hit throttle hold and picked the heli up and began carrying it to the picnic table by the blade grips and it started to spin and take off by itself. Luckily I had the remote in one hand and hit throttle cut to power down. Before I rip the motor out and check the bearings, do you guys think my throttle servo is going bad and that's the problem with it revving up and trying to spin with hold engaged as well as having no power. Any help would be appreciated. I did just order a new throttle servo but I would like to hear your thoughts as well. This problem began 4 flight ago and has gotten progressively worse.

dbcaster · 10-25-2016, 03:10 PM

What FBL are you using?

dominator · 10-25-2016, 04:01 PM

Bad servo or possibly a switch going bad on transmitter. Check the servo horn on the carb. Is it loose?

Locktite · 10-25-2016, 04:03 PM

What servo are you using.. I think it is a bad servo...I do not think it has anything to do with the motor but make sure your magnets are still in the fan and your sensor is operating properly..check with the datapod.. make sure your Spartan sees the magnet

Wyno · 10-25-2016, 04:43 PM

I just powered it up on the kitchen table and everything powered up. I checked the sensor first and it is working. I then checked the servo-carb arm and everything tight there. I then put it into stunt 1 and moved the collective up and down and bingo, the servo went completely dead. I moved it by hand back and forth and it jumped back to life with power. I now know its the throttle servo and not the motor. Its the BK7002 servo. Its the 3rd BK servo to fail on this bird. Thanks guys for your input and I'm glad I got it figured out.

Locktite · 10-25-2016, 04:49 PM

I didn't want to be the one to say if it is a BK servo change it..sure enough that's it.. glad you found the issue..

Eury · 10-25-2016, 05:01 PM

Good to hear that I'm not the only one who has found BKs less than reliable.

Wyno · 10-25-2016, 05:07 PM

For sure, 3rd time on this bird. I think I learned my lesson!!!!!!!!!!!!!

Eury · 10-25-2016, 05:14 PM

Yeah, my N5C is down because one of the BKs is doing something strange. I've learned my lesson. They seem to be good in electrics, but don't last in nitros.

Wyno · 10-25-2016, 05:23 PM

I ran them in my 700 comp for 2.5 years without issue doing over 1200 flights. I'm only at 104 on my black nitro and I've been through 1 tail servo and 2 cyclic servos. I think I might switch to MKS in the near future.

Wyno · 10-25-2016, 06:19 PM

I have a brand new tail servo sitting around, can it be put on to run the throttle or should I use a cyclic servo.

Locktite · 10-25-2016, 07:53 PM

I run a torq tail servo on my throttle. Just make sure you change the frequency, should be 760, when setting up in Spartan studio or datapod

Wyno · 10-25-2016, 08:12 PM

Thanks, went ahead and did that and its ready for test fly tomorrow with tail servo for throttle.

10-25-2016, 03:00 PM	#1 (permalink)
Wyno Registered Users Join Date: Dec 2013	Black Nitro Issue!!!! Well, I was on flight 104 today and I noticed the last couple flights that my OS105hzr was making a weird sound, it kept revving up and down really loud a couple times each flight. It sounded like you was revving up a sports car. My last flight it got really bad so I hit throttle cut and landed. I took the canopy off and the throttle servo had no power to it, all the other servos were working perfectly. I touched the servo wire and the power came back on. I played with the wire for a few minutes after and it never once lost power. So idiot me decided to fire it up again and burn the half tank of fuel out. I fired it up and started to increase throttle stick and the heli began revving up on the ground and stuttering really bad so I hit throttle hold and picked the heli up and began carrying it to the picnic table by the blade grips and it started to spin and take off by itself. Luckily I had the remote in one hand and hit throttle cut to power down. Before I rip the motor out and check the bearings, do you guys think my throttle servo is going bad and that's the problem with it revving up and trying to spin with hold engaged as well as having no power. Any help would be appreciated. I did just order a new throttle servo but I would like to hear your thoughts as well. This problem began 4 flight ago and has gotten progressively worse.

10-25-2016, 04:03 PM	#4 (permalink)
Locktite Registered Users Join Date: Jun 2006	What servo are you using.. I think it is a bad servo...I do not think it has anything to do with the motor but make sure your magnets are still in the fan and your sensor is operating properly..check with the datapod.. make sure your Spartan sees the magnet __________________ Tron 7.0 Tron 5.5 Tron Nitron Tron 5.8 VTouch/Neo

10-25-2016, 04:49 PM	#6 (permalink)
Locktite Registered Users Join Date: Jun 2006	I didn't want to be the one to say if it is a BK servo change it..sure enough that's it.. glad you found the issue.. __________________ Tron 7.0 Tron 5.5 Tron Nitron Tron 5.8 VTouch/Neo

10-25-2016, 07:53 PM	#12 (permalink)
Locktite Registered Users Join Date: Jun 2006	I run a torq tail servo on my throttle. Just make sure you change the frequency, should be 760, when setting up in Spartan studio or datapod __________________ Tron 7.0 Tron 5.5 Tron Nitron Tron 5.8 VTouch/Neo

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10-25-2016, 03:10 PM	#2 (permalink)
dbcaster Registered Users Join Date: Jul 2005	What FBL are you using?

10-25-2016, 04:01 PM	#3 (permalink)
dominator Registered Users Join Date: Dec 2013	Bad servo or possibly a switch going bad on transmitter. Check the servo horn on the carb. Is it loose?

10-25-2016, 04:43 PM	#5 (permalink)
Wyno Registered Users Thread Starter Join Date: Dec 2013	I just powered it up on the kitchen table and everything powered up. I checked the sensor first and it is working. I then checked the servo-carb arm and everything tight there. I then put it into stunt 1 and moved the collective up and down and bingo, the servo went completely dead. I moved it by hand back and forth and it jumped back to life with power. I now know its the throttle servo and not the motor. Its the BK7002 servo. Its the 3rd BK servo to fail on this bird. Thanks guys for your input and I'm glad I got it figured out.

10-25-2016, 05:01 PM	#7 (permalink)
Eury Registered Users My HF Map location Join Date: Apr 2005 Location: Dover NH USA	Good to hear that I'm not the only one who has found BKs less than reliable.

10-25-2016, 05:07 PM	#8 (permalink)
Wyno Registered Users Thread Starter Join Date: Dec 2013	For sure, 3rd time on this bird. I think I learned my lesson!!!!!!!!!!!!!

10-25-2016, 05:14 PM	#9 (permalink)
Eury Registered Users My HF Map location Join Date: Apr 2005 Location: Dover NH USA	Yeah, my N5C is down because one of the BKs is doing something strange. I've learned my lesson. They seem to be good in electrics, but don't last in nitros.

10-25-2016, 05:23 PM	#10 (permalink)
Wyno Registered Users Thread Starter Join Date: Dec 2013	I ran them in my 700 comp for 2.5 years without issue doing over 1200 flights. I'm only at 104 on my black nitro and I've been through 1 tail servo and 2 cyclic servos. I think I might switch to MKS in the near future.

10-25-2016, 06:19 PM	#11 (permalink)
Wyno Registered Users Thread Starter Join Date: Dec 2013	I have a brand new tail servo sitting around, can it be put on to run the throttle or should I use a cyclic servo.

10-25-2016, 08:12 PM	#13 (permalink)
Wyno Registered Users Thread Starter Join Date: Dec 2013	Thanks, went ahead and did that and its ready for test fly tomorrow with tail servo for throttle.

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