HobbyKing ™ BL-89601 Digital Brushless Servo HV / MG 6.0kg / 0.06sec / 56g

• Overall
• Quality
• Value

Customer Rated

May 07, 2013

ATENCION ! NO USEN ESTE SERVO EL LA COLA DE UN HELICOPTERO . el servo no es malo, pero produce oscilaciones en la cola del heli ,como lo explica en el comentario el usuario SMPRC.
ATTENTION! DO NOT USE THIS SERVO THE TAIL OF A HELICOPTER. the servo is not bad, but produces oscillations in the tail of the heli, as user SMPRC explains in the comments.
I put it on a G4 Raptor and I had to change it, tail ranged almost permanently due to the servo.

• Overall
• Quality
• Value

Customer Rated

Jul 24, 2012

When I received BL 89601 servo I really have a good feeling about it. Smooth movement no slope aluminum middle part. I want to check it, so I open it. Gear part is connected to the main part with 3 wires, and after a couple of moves, one of the contact fell of. Oh boy, that couldnt last long. I was able to re solder that wire and I checked the other soldering spots, but seem that there was a better work.

Im using that servo on the 600 size helicopter for the tail. It works on 6V and it works very well. This is my first servo for the tail, on that size of the helicopter, which works absolutely cool.

I tried also the MI digital HK 47902 TM-HV on the same helicopter and I have to say that this servo works even better, but after the flight it is a little warm.

• Overall
• Quality
• Value

Customer Rated

May 06, 2012

This is an update to the long-winded review I made for the BL-89601 servo yesterday. With only a few minutes of bench testing (on 2S LiPo power, Spektrum AR600 receiver), this servo has developed a very serious hesitation issue. Sometimes it will "stick" and not move (under a command to move) unless I push on the output arm. Its actions perfectly mimic a brushed-motor servo with worn/dirty brushes/commutator. Sometimes when 'stuck', the quiescent current would spike up to .50A from a normal resting current of .07A, allowing heat to be noticed in the case. Nudging the arm would "unstick" the motor and the current would drop back to the idle state. If I could guess, I'd say there's a bad Hall-effect sensor in the motor circuit and correct rotor motion can't be determined. There's forty one dollars down the drain :-( I've derated the score for this servo. 1 Crown for overall rating, 1 Crown for value but must admit the quality is still worthy of a four.

• Overall
• Quality
• Value

Customer Rated

May 05, 2012

Received one of these servos today (May 4, '12) and performed a little bench testing on 2S LiPo, fully charged. Overall the BL-89601 works OK but there are four things that I'm going to mention here.

First, if this servo is going to be installed in a heli as a tail servo, the deadband is greater than optimum, @3uS vs 1uS or less.

Second, with no load, just working the servo moderately fast with the transmitter stick, it doesn't take more than a few seconds before heat is noticed in the metal case center section. It's good that the motor's heat is brought outside to be dissipated efficiently but why, with the claim of "...low drain brushless motors..." is so much heat being generated? How much hotter will it get when doing real work?

Third, if the servo is moved at a 'moderate' speed, there's a chattering sound created from the combination of the solid, all-metal gear train and some characteristic of the brushless motor controller working together. I wouldn't say this is any indication of a problem but the coarse sound is impossible to ignore.

Fourth, with no input to change position commanded, the servo like to hunt or chatter a little. This is something within the servo, not from it responding to unsteady input signals. Clearly if the deadband was tighter this chattering would be far worse.

I opened the servo case to see the internal build quality and was very please