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|03-05-2021, 07:04 PM||#1 (permalink)|
Join Date: Jan 2006
JR "Game Changer-2K" Servos
Prior to this, JR's new servo synchronization feature was only available for XBus use. As the outputs of the current three-axis gyros on the market are PWM, the feature was not available to RC helicopter fliers.
This has now changed.
Servo Synchronization is now available for PWM applications (Tomohisa Konishi has posted several videos of this in the last couple of weeks). New servos with new firmware allow helicopter fliers to take advantage of this.
I was given the privilege of being the first person in the U.S. to test the new “Game Changer”/synchronized servos in a helicopter for JR PROPO/Dee Force Aviation.
For servo synchronization, a special sliding swashplate leveler with ball studs is used (neither the head, nor the swashplate are installed on the machine during the synchronization process). The servos are set up as normal on the helicopter, but the links from the servo arms are connected to the ball studs on the leveler instead of the swashplate.. The servos must be mounted as rigidly as possible in order to achieve good synchronization.
The servos are disconnected from the FBL unit during the synchronization process.
Using the latest version of the JR XBus Servo Programmer, one servo is programmed as the “Master” servo, the other two as “Follower” servos. The maximum and minimum (full travel in each direction of rotation) are set manually, based on prompts in the Programmer’s display.
Once this is done, the Synchronization Program is initiated. The positions of the Follower Servo arms are compared to that of the Master Servo at each of 120 points in its rotation. First one of the Follower servos is matched to the Master servo, then the other (you can see the entire process happening twice). The total time required for synching is around 20 minutes, give or take a few minutes.
Once the process is complete and the servos fully synchronized, all threes servos will all be at the exact same position in their rotation at each of 120 points in their rotation, given the same pulse width from the FBL unit.
After synchronization, it is necessary to perform a full setup on again on the FBL unit.
I didn’t know what to expect with this-I didn’t really expect anything profound. I had been instructed by JR PROPO to turn the gyro gains down before test flying, which I did.
I also turned down the overall throws on the cyclic, as a precaution.
I should point out that I have been flying a Forza 700 for years now (with JR Servos), and am very familiar with its flight characteristics.
The first thing I noticed when lifting it off the pad, was that it was far more precise.
The second thing was that it still had more gyro gain on the cyclic than it needed.
After making some more adjustments, I put it in Idle Up 1 and flew it around, flipping and rolling it to get the feel of it, landing it and tuning a bit, then taking it up again.
The improvement with the Servo Synchronization is, IMHO, profound. The helicopter’s response was more direct, more precise, and more proportional than anything I have ever flown (in the last 45 years).
JR’s Servo Synchronization for PWM servos for helicopter use is, IMHO, literally a “Game Changer.”
Set up video (preparation for synchronizing):
KBDD-Team Captain, JR DFA Team Pilot. Forza 450, Forza 600N, Forza 700,
Compass 6HV-U, Warp, 7HV,Knight Pro,Knight 3D, Atom, Odin II, 6HV, 3D Plus, Knight 50, Chronos, Velos, Steam 550 and 600, OMP M2 (and anything else I can get my hands on...).