5955tg's Stopping Mid Travel...

[Pro1Foam]

Just finished installing two 5955tg's per control surface (aile's and elev's). Have each surface y'ed to one lead to each. All servos seem to be traveling the same. I start throwing the sticks around drulling over the speed and a couple of servos stop!! givem a sec and they strat working good again..... untill they stop again. happens on more than one surface. Running fresh charged 6v packs.

Any thoughts? may be signal loss... also set the deadband on each servo higher than norm in hopes of them not fighting each other as much.

Tx






0

[Pro1Foam]

the 5955's are ver 1.04

[ericb]

Did you program the servos with the programmer first? If not, I would definitely check that they are not fighting each other with using the Y.

[fastace]

if you have enough channels spare on the receiver , dont use the Y lead.

[Pro1Foam]

After sleeping on it, I think I will go back and reset all servos to factory specs and try again. Seems like it is happening on the ones i turned the deadband up on. (not sure)

[JoeAirPort]

Be careful, if they tripping out on high temperature or current you could be burning them up. The linkages need to be matched with precision. As precise as you can get. Little paper protractors on the servos and surfaces will help with this. The deadband would help in a situation where the linkages are not matched, but only when the servos are told to stop and hold positon (at center for example). The deadband is not stopping them from responding though. It's probably that they are binding and overheating. What you can do is move the surface slowly from one end to the other and listen to the squealing of the servos. If it gets too loud they are fighting. You can also hook up an in-line H9 servo current meter and do the same test. That will reveal a lot about your setup.

[Pro1Foam]

	Quote: Originally Posted by JoeAirPort
	Be careful, if they tripping out on high temperature or current you could be burning them up. The linkages need to be matched with precision. As precise as you can get. Little paper protractors on the servos and surfaces will help with this. The deadband would help in a situation where the linkages are not matched, but only when the servos are told to stop and hold positon (at center for example). The deadband is not stopping them from responding though. It's probably that they are binding and overheating.

Point well taken. I did not know they would shut down on over current/heat. I did check and all seemed to be matched up (little buzzing) except for the last couple of degrees of travel.

[Pro1Foam]

I will rig up my fluke current meter tonight also. any one know the trip current on these little buggers?

[cjcyclesrc]

7955's have overload protection. 5955's don't. 5955's usually melt the backplate off when the go out.


Your problem is interesting. Do the gears feel smooth all the way through?

[JoeAirPort]

That's true I don't think the 5955's have overload protection. Maybe you are stalling out the servos due to browning out the battery? When you back off moving the sticks, the voltage comes back and it starts to work again? Could even be reseting the receiver. I wouldn't fly that's for sure !!!!

[Pro1Foam]

Browning the batts may be possible and resetting to servo's but the rest of the servos are working when one or two stop. I know it takes a sec upon inital power up for the servos to start working. That rules the rx resetting out.
Useing two JR 2700mAh nimh, two switchs, both pluged into different channels on the Rx.

Gears are good.

I will also stick a a min/max meter on the voltage and see if it is dropping out.

[JoeAirPort]

I've made up a servo extension that has alligator clips on one side to hook up to my Fluke meter leads. You can plug the JR plug into an unused servo port to get a voltage reading on the receiver's power bus as you throw the sticks. It's pretty cool to watch the voltage as you do this. I did a simulated rolling harrier and the voltage really dropped. Or just throw all the sticks all over the place at once. That works too. I also remember it dropping as the elevators went to full 3D travel (almost 50 degrees). That made me back off the end points a few clicks. Helped a lot.

[Pro1Foam]

Wish I knew what the brownout voltage is on these things.

[JoeAirPort]

Well the easy answer is anything below 4.8V per their spec. But I'd think they operate below that at a lower torque. When they stop moving period, not sure (like when the servo processor shuts down). You could always get a regulated power supply with an adjustable voltage output and test it.

I'd just put an in-line amp meter on each servo to see if they are drawing too much current.

[Pro1Foam]

current a slow travel with two servos was not over .6 amps fast travel not over 1.5 amps. voltage at rx never dropping below 6.12 volts. Going to reset all servos to factory and go from there.