Large Scale Central

Servo shutting off

Electronics Power and Sound
#1

My one servo seems to randomly shut itself off. Ill be running it and then all of a sudden the servo will loose connection and turn the throttle off rather then staying in the position it was in. The other servo just stays in the position it was in. It did it with two different receivers and controllers. Does it sound like a servo problem or battery problem?

#2

Hi Shawn.

Servos are normally pretty reliable electrically.

You really need another servo to find out what it is that has gone wrong.

#3

Ill give it a try. By the way the TX-2 is awesome. Im very happy wit it. Now I have to get a steam whistle to try out the other features.

#4

Shawn,
If you need servos, let me know I have a drawer full of them from my RC cars.

#5

Shawn (napkin builder) Viggiano said:

Ill give it a try. By the way the TX-2 is awesome. Im very happy wit it. Now I have to get a steam whistle to try out the other features.

Thanks Shawn.
So far I have not had any adverse user comments.

I would be interested to hear what sort of battery life you obtain.

#6

Tony Walsham said:

Hi Shawn.

Servos are normally pretty reliable electrically.

You really need another servo to find out what it is that has gone wrong.

Tony

He has 2 servos. He could switch them to see if it is the servo.

Tom

#7

Tom my stab at a guess is the RX got too hot. They can do weird things when that happens.

#8

Shawn

Perhaps the servo is working to hard; has a bind somewhere in the travel arc or may simply be problematic. More often than not servo linkage setups require more attention than given in my experience. Travel arc volume is generally suspect, most servos rotate in a 120 degree arc, 60 degrees either side of neutral. Some transmitters allow you to decrease the pulse width signal to limit travel in both directions. That said a mechanical answer is best with proper servo and control arm lengths taking full advantage of the servos inherent finite travel steps for best resolution.

Some small servos MUST use no more than 4.8V or ???

Michael

#9

Thanks for the input guys. I had a chance to play with the servos etc… today. Its not the servo because they both do it at the same time. Im using the orange rx. It has two antennas and I had both inside the bunker. I did find that at close range the servos will work but as the train got further the throttle would shut off and the Johnson bar servo wont move at all. Once I get closer it reconnects although I found sometimes it took 10 seconds to reconnect. Im assuming I need to have the two wire antennas sticking outside the bunker? My problem is the two antennas are placed on different sides. I can hang one outside the bunker but not the other. Originally I was using the planet rx and it worked fine inside the bunker until about a few months ago and even that one started to kick off like the Orange rx. That baffals me because… Im going to switch the batter out with a li ion. I cold still be the rx getting hot although it will reconnect when I get closer.

#10

Shawn

How are the antennas orientated? They should be at 90 degree right angles from one another.

Michael

#11

I doubt changing the battery will make any difference.

I have experience of the Planet RX’s playing up when they got hot inside Live Steam locos.
Have not experienced Orange RX’s playing up when hot, but I guess they could.

#12

Thanks guys. Michael the antennas are just loose when i put the RX inside. I might have to place the RX on top of the bunker or under the cab roof that way I can position the antennas correctly and see how that works. Ill give it a test monday.

#13

I finally had a chance to play with the servo. Yesterday while running the Forney everything worked fine as long as I was very close to the RX. It was not the servo because they both would loose reception. What I found odd was that when I lost reception the servo would automatically shut the throttle off but the servo on the Johnson bar stayed in the same position. Is this normal?

I ended up putting a lith ion battery in, mainly because they last longer and they don’t loose charge as quickly. Im using a 7.4v battery and the Orange RX does not get hot with it. I also took the Orange RX and placed it inside the cab. Being in the metal bunker was part of the problem. After getting everything back together I did a test run. Everything seemed to work much better. As long as I stayed in the middle part of my layout. Once the train got to the furthest end of the layout it would shut down or when in the tunnel but if I moved a little closer it would turn back on. Im guessing that is reasonable to happen?

#14

HI

iIt sounds like you have a radio signal problem along with other things.

Something we used to do with RC airplanes was to run the recvr antenna thru a soda straw to keep it in place. That might help some - -also don’t point the xmitter antenna at the recvr vertical gives the best signal.

Bill

#15

Hi Shawn - I agree with Bill. The servo behavior when it looses signal is the fail safe. The fail safe behavior is usually programmable - you should be able to change it to “do nothing” which may just solve your problem - at least keep the loco from stopping while out of range.

Not sure how you program an Orange. I have instructions for the Spektrum Rx. I wonder if it is the same. I also have several Orange receivers and haven’t noticed any range issue in plastic models. But I usually stay close to the loco.

How are your Tx batteries?

#16

Found this with Google…

Setting failsafe on OrangeRX DSM receivers

Hi,
If one needs all channels to go to some specific positions on signal lost, one should bind the receiver in the following way:

  • TX & RX off
  • Plug the binding plug
  • Switch on the RX -> flashes
  • Remove the binding plug -> RX keeps flashing
  • Switch on the TX in binding mode with the sticks at desired positions

This worked for me with(Dx6i) with the 6ch as well as with 9ch receiver from OrangeRx. I think it is the same procedure with most genuine spektrum receivers.
If you don’t remove the plug before switching on the TX, only the throttle channel will move (to zero) in case of a signal loss (“Preset failsafe” mode, as mentioned above). Hope this helps!

#17

That procedure requires the setting of a “fail safe” position.

Is there any way of simply disabling the fail safe?

#18

Thanks guys. Im assuming the new RCS TX-2 transmitter will work for setting the fail safe? Ill give it a try and see what happens. I just dont like it shutting off. I would rather the throttle stay at one spot. Thanks Jon.

#19

Shawn,

The way I read it, if the RX has to use a binding plug and then remove it, I would think it makes no difference what the DSM2 compatible TX is.

I believe the crux of the problem lies in why the RX is losing signal. It is likely one of two reasons.

  1. The RX is overheating, shutting off and not receiving a signal.

  2. The TX-2 signal is not getting through properly.

Although the system has been tested thoroughly in metal locos with very good results, different locos may give less than perfect results.

Might I suggest that as an experiment;

  1. Place the RX away from any heat and retest.

  2. If possible locate the RX so that the RX antenna is external to the loco. Even temporarily, just to see what happens.

#20

Thanks Tony
. I dont think its overheating because it does not feel warm and as soon as I move closer it pops back on. It is most noticable when it goes into my tunnel or the far end of the layout. Since taking the receiver out of the metal bunker the reception got better and allows me to get better range. I can stand 20ft or so away now. What is the range for the TX?

The reception is good enough for me now. I just wish the throttle would not shut off when i I loose reception especially in the tunnel.