Hi all,

I'm building one Top Flite giant P47.
I have the jr R921X receiver and I thinking in to use this configuration:


throttle =(1) JR ds821
aileron = Y-Harness, Heavy-Duty using 2 JR DS8231
elevator + aux2 channnel (mixed mode) -> JR DS8411 - 1 servo for channel
rudder + aux3 channnel (mixed mode) -> JR DS8411 - 1 servo for channel
gear = JR-PS368BB
aux1 (Flap) = Y-Harness, Heavy-Duty using 2 JR DS8231
aux4 = auxiliar batt
Batt = 2X JR Receiver 4.8V Pack 2500mah NiMH (for redundancy)

Is safe to use 2 servos DS8231 at the same channel?

Is the receiver R921X Strong enough to manager (4)JR DS8231 and (4)JR DS8411 without power box?

What do you think about it?

I'm choosing (4) JR DS8231 and (4) JR DS8411 and not (8)JR DS8411 because I'm not sure I can use two JR DS8411 in the same channel (aileron for example).

I want to user 4.8V batteries because I think is not necessary use the maximun of the servos power on warbird plane.


suggestions are appreciated!


Many Thanks!

What type of transmitter ?

Originally Posted by ganobile

Hi all,

I'm building one Top Flite giant P47.
I have the jr R921X receiver and I thinking in to use this configuration:


throttle =(1) JR ds821
aileron = Y-Harness, Heavy-Duty using 2 JR DS8231
elevator + aux2 channnel (mixed mode) -> JR DS8411 - 1 servo for channel
rudder + aux3 channnel (mixed mode) -> JR DS8411 - 1 servo for channel
gear = JR-PS368BB
aux1 (Flap) = Y-Harness, Heavy-Duty using 2 JR DS8231
aux4 = auxiliar batt
Batt = 2X JR Receiver 4.8V Pack 2500mah NiMH (for redundancy)

Is safe to use 2 servos DS8231 at the same channel?

Is the receiver R921X Strong enough to manager (4)JR DS8231 and (4)JR DS8411 without power box?

What do you think about it?

I'm choosing (4) JR DS8231 and (4) JR DS8411 and not (8)JR DS8411 because I'm not sure I can use two JR DS8411 in the same channel (aileron for example).

I want to user 4.8V batteries because I think is not necessary use the maximun of the servos power on warbird plane.


suggestions are appreciated!


Many Thanks!

Do you still have the owners manual to the R921X receiver? Look at the topic about "Power Requirements". They are pretty much telling you that you should be using a power source that NEVER drops below 4.8 volts with the servos under a real load. Even tho the voltage cutoff is 3.5 volts JR wants you to stay above 4.8 as a minimum! If this was my large scale P-47 I would never even consider using 4.8 volt battery packs in a 2.4 GHz system! You are leaving yourself with practically no safety cushion. Look at all of the high torque servos you are running. Even in my smaller planes I use 6 volt battery packs for very real safety reasons. BTW, the receiver can handle the servos easily, it's the batteries that you are going to use that are the weak link.

Originally Posted by Codimasta

What type of transmitter ?

Hello, transmitter is JR11X

Originally Posted by crazy8s

Do you still have the owners manual to the R921X receiver? Look at the topic about "Power Requirements". They are pretty much telling you that you should be using a power source that NEVER drops below 4.8 volts with the servos under a real load. Even tho the voltage cutoff is 3.5 volts JR wants you to stay above 4.8 as a minimum! If this was my large scale P-47 I would never even consider using 4.8 volt battery packs in a 2.4 GHz system! You are leaving yourself with practically no safety cushion. Look at all of the high torque servos you are running. Even in my smaller planes I use 6 volt battery packs for very real safety reasons. BTW, the receiver can handle the servos easily, it's the batteries that you are going to use that are the weak link.

Thanks a lot for your considerations, so do you thinks use two LiFe 2100 mah 6.6Volts is a good option?

Originally Posted by ganobile

Hi all,

I'm building one Top Flite giant P47.
I have the jr R921X receiver and I thinking in to use this configuration:


throttle =(1) JR ds821
aileron = Y-Harness, Heavy-Duty using 2 JR DS8231
elevator + aux2 channnel (mixed mode) -> JR DS8411 - 1 servo for channel
rudder + aux3 channnel (mixed mode) -> JR DS8411 - 1 servo for channel
gear = JR-PS368BB
aux1 (Flap) = Y-Harness, Heavy-Duty using 2 JR DS8231
aux4 = auxiliar batt
Batt = 2X JR Receiver 4.8V Pack 2500mah NiMH (for redundancy)

Is safe to use 2 servos DS8231 at the same channel?

Is the receiver R921X Strong enough to manager (4)JR DS8231 and (4)JR DS8411 without power box?

What do you think about it?

I'm choosing (4) JR DS8231 and (4) JR DS8411 and not (8)JR DS8411 because I'm not sure I can use two JR DS8411 in the same channel (aileron for example).

I want to user 4.8V batteries because I think is not necessary use the maximun of the servos power on warbird plane.


suggestions are appreciated!


Many Thanks!

I have the Hangar 9 P47-150 with a Fuji 32ei gas engine. I was using he JR921 DSM2 Rx, but now I am using the Spektrum AR9010 DSMX Rx. I have a JR XP9303 with Spektrum DSM2 module. I switched Rx's because I had to send the 921 in for service.

I have two Aileron servos, two Elevator servos, two Flap servos, two Retract servos, one Rudder servo, and one Throttle servo. I use a 2500mah 2cell LiFe Rx battery and a 2500mah 2cell LiFe Ignition battery (with 5v regulator).

I have a JR Matchbox on the Elevators and another on the Flaps. I have used Y Harnesses in the past and encountered enough anomalies that I will never use them again when I can use Channel Mixing or a Matchbox, instead.

Never use 4.8v Rx batteries with 2.4 Rx's. It is well documented that servo load can cause the Rx battery voltage to drop below critical and cause a Brownout on any manufacturer's 2.4 Rx. I have never had a Brownout on any of my aircraft and I have been using JR/Spektrum Rx's since 2007.

With your 11X, you could connect every servo to a separate channel and avoid using a Y Harness. I am limited with 9 channels.

Originally Posted by Buschbarber

I have the Hangar 9 P47-150 with a Fuji 32ei gas engine. I was using he JR921 DSM2 Rx, but now I am using the Spektrum AR9010 DSMX Rx. I have a JR XP9303 with Spektrum DSM2 module. I switched Rx's because I had to send the 921 in for service.

I have two Aileron servos, two Elevator servos, two Flap servos, two Retract servos, one Rudder servo, and one Throttle servo. I use a 2500mah 2cell LiFe Rx battery and a 2500mah 2cell LiFe Ignition battery (with 5v regulator).

I have a JR Matchbox on the Elevators and another on the Flaps. I have used Y Harnesses in the past and encountered enough anomalies that I will never use them again when I can use Channel Mixing or a Matchbox, instead.

Never use 4.8v Rx batteries with 2.4 Rx's. It is well documented that servo load can cause the Rx battery voltage to drop below critical and cause a Brownout on any manufacturer's 2.4 Rx. I have never had a Brownout on any of my aircraft and I have been using JR/Spektrum Rx's since 2007.

With your 11X, you could connect every servo to a separate channel and avoid using a Y Harness. I am limited with 9 channels.

Hi, thanks for your comments. I limited with 9 channels to. I think I will use a Matchbox (for flaps and ailerons).

Can you please tell me what servos you are using on your plane?


Regards.

I was reading the R921X manual. There are a data/binding port. Can I connect a Aux Batt on this port? If yes I can free the channel aux4 and I can mix the aileron with this channel.

Originally Posted by ganobile

I was reading the R921X manual. There are a data/binding port. Can I connect a Aux Batt on this port? If yes I can free the channel aux4 and I can mix the aileron with this channel.

You can connect a battery to any of the ports on that receiver. They all share the same Buss. You can connect a Y Harness to any servo port and connect a battery to one side and the servo to the other.

I don't have the R921 in front of me, but I believe it has a separate Bind/Bat port and a separate Data Port. You can connect a Y Harness to the Bind/Bat port so you can connect a battery to one side and Bind through the other side. You can connect a Y Harness to the Data Port and connect a battery to one side and a Flight Logger or Telemetry Module to the other side.

I had a situation where I needed to use a Voltage Regulator for the Rx battery. It was connected between the Switch Harness and the Rx. I could no longer Bind through the Switch Harness Charge Jack so I needed to connect a Y Harness to the Bat/Bind port.

These are the only situations where I use a Y Harness in larger aircraft.

Originally Posted by Buschbarber

You can connect a battery to any of the ports on that receiver. They all share the same Buss. You can connect a Y Harness to any servo port and connect a battery to one side and the servo to the other.

I don't have the R921 in front of me, but I believe it has a separate Bind/Bat port and a separate Data Port. You can connect a Y Harness to the Bind/Bat port so you can connect a battery to one side and Bind through the other side. You can connect a Y Harness to the Data Port and connect a battery to one side and a Flight Logger or Telemetry Module to the other side.

I had a situation where I needed to use a Voltage Regulator for the Rx battery. It was connected between the Switch Harness and the Rx. I could no longer Bind through the Switch Harness Charge Jack so I needed to connect a Y Harness to the Bat/Bind port.

These are the only situations where I use a Y Harness in larger aircraft.

Nice. Thanks! You gave good Ideas