View Full Version : JR 770 3d / futaba 9257 servo output speed?
lowflyer101
01-20-2008, 09:58 AM
just about install new jr770 3d on my trex500 with futaba s9257 digital servo
what is servo outpust speed select for futaba 9257 digital? high or low ?
thank forward,
DavidH
01-20-2008, 11:44 AM
Are you talking about the pulse rate?
Don't know about the Futaba digital servos with JR gyros. But the JR digital servos and Futaba GY gyros are not compatible with each other. The JR servos will go full travel one direction on initialization of the Futaba gyro.
David
Pinecone
01-20-2008, 05:40 PM
Huh, I run a GY gyro with a JR digital servo (401 w/ 3400G)
Only the 601/611 require special servos and will not work with standard digital servos (JR or Futaba).
DavidH
01-20-2008, 06:46 PM
Huh, I run a GY gyro with a JR digital servo (401 w/ 3400G)
Only the 601/611 require special servos and will not work with standard digital servos (JR or Futaba).
OK do some research back a few years ago with the GY 401 and 502. I have seen many reports with owners of those gyros trying to use JR 8700G servos with the above gyros. All the reports that when the gyro intialized that the servo would go full travel one direction. I have even seen it happen myself.
Maybe JR has changed the pulse rates on there servos. I am positive Futaba has not changed the gyros.
Yes I know the GY 601/611 can only use the Futaba servos that can handle the pulse rate from the gyros. At this time it is the 9251 or 9256.
David
lowflyer101
01-20-2008, 10:26 PM
Are you talking about the pulse rate?
Don't know about the Futaba digital servos with JR gyros. But the JR digital servos and Futaba GY gyros are not compatible with each other. The JR servos will go full travel one direction on initialization of the Futaba gyro.
David
yes, fulse rate.
That was using the 8700 series on Futaba gyros,
the 8900 works fine with Futaba gyros
The S9257 should work fine with the JR770
You can and should use the high speed (frame rate) option
j bomb
01-21-2008, 10:27 AM
I think the 8700 has a faster frame rate than a standard analog servo, but it's not a true digital. The 3400 and 8900 are true digital servos. I use a 3400G w/ a GY401 in DS mode on my 450 and it works just fine.
The Spartan manual says to use the 8700 at 250hz - standard digital frame rate
the 8900 can be used in high speed/frame rate - 333hz