Aurora 9 with DS8717 Servos

[MTDV]

I had DS8717 servos on my heli running very well with DX7, and now I switched to Aurora 9 to take an advance of its telemetry features. However, I got an issue with the DS8717 servos. DS8717 only responsed from 0 to 70% of the travel setting. Anything above 70% (roughtly 71%) all DS8717s do not response and have no torque (you can move servo wheel by hand), and they will response again when the stick moving below 70%.

I remember of reading somewhere on HF about the DS8717 digital frame rate, but I couldn't find the thread anywhere. Is there any way that I can se the frame rate for DS8717 on the Aurora 9?

Would you guys help me to figure out? Thanks.

MT

[A.T.]

Originally Posted by MTDV

I had DS8717 servos on my heli running very well with DX7, and now I switched to Aurora 9 to take an advance of its telemetry features. However, I got an issue with the DS8717 servos. DS8717 only responsed from 0 to 70% of the travel setting. Anything above 70% (roughtly 71%) all DS8717s do not response and have no torque (you can move servo wheel by hand), and they will response again when the stick moving below 70%. I remember of reading somewhere on HF about the DS8717 digital frame rate, but I couldn't find the thread anywhere. Is there any way that I can se the frame rate for DS8717 on the Aurora 9? Would you guys help me to figure out? Thanks. MT

Perhaps EPA is to wide, beyond the capability of those servo.
This thread:
Gyro - Servo Resolution - Frame Rate & Compatibility Explained may assist.

[additional to above thread, Pulse Data =

All Hitec servos require 3-5V peak to peak square wave pulse. Pulse duration is from
0.9mS to 2.1mS with 1.5mS as center. The pulse refreshes at 50Hz (20mS).
JR do not appear to have released similar detail for the DS8717 whereas they have for some others.]

Alan T.
Alan's Hobby, Model & RC FAQ Web Links

[MTDV]

Originally Posted by A.T.

Perhaps EPA is to wide, beyond the capability of those servo.
This thread:
Gyro - Servo Resolution - Frame Rate & Compatibility Explained may assist.

[additional to above thread, Pulse Data =

All Hitec servos require 3-5V peak to peak square wave pulse. Pulse duration is from
0.9mS to 2.1mS with 1.5mS as center. The pulse refreshes at 50Hz (20mS).
JR do not appear to have released similar detail for the DS8717 whereas they have for some others.]

Alan T.
Alan's Hobby, Model & RC FAQ Web Links

You are absolutely right. It works normal at 100% travel.

[A.T.]

Originally Posted by A.T.

Perhaps EPA is to wide, beyond the capability of those servo.
This thread:
Gyro - Servo Resolution - Frame Rate & Compatibility Explained may assist.
[additional to above thread, Pulse Data =

All Hitec servos require 3-5V peak to peak square wave pulse. Pulse duration is from
0.9mS to 2.1mS with 1.5mS as center. The pulse refreshes at 50Hz (20mS).
JR do not appear to have released similar detail for the DS8717 whereas they have for some others.]

Alan T.

Alan's Hobby, Model & RC FAQ Web Links

Refresh rate for Hitec Digital Servo - Update:
"Current digital servos are 300hz (300 times per/sec) while the new brushless will be 800Khz. Yep, that's Khz so 800,000 times per second" - Mike
"What we've found with the brushless vs. coreless is that the speed of the servo does not slow down the closer it gets to the limits. While both motors stall at 486in/oz, the coreless will start laboring and slow down below that, where the brushless will not, therefor if asking 80-90% of the servo at all times the brushless will be much crisper feeling. "

Alan T.
Alan's Hobby, Model & RC FAQ Web Links