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[Nordlys]

I'm looking at a futaba s3003 servo. Specification says 60 degree rotation. Is this measured while under power?
Mine is rotating full 180 but not under power. Is this correct anyone?
N.
Edit.  Only asking as I'm not able to power it up at the moment, waiting for receiver.

[HMS Invisible]

60^o is an error in the servodatabase website. The S148 says 180^o which is the mechanical limit you get with the moulded end stop. The servo feedback pot would be damaged beyond 3/4 turn.
  Under power, span of rotation will be +/-45^o for a typical 1-2millisecond RC pulse span from the transmitter. You can change the rotation span from the transmitter or surgery on the servo.

Note S148 and S3003 counterclockwise (CCW) direction for longer pulses and nonlinearity in span of movement with larger pwm span.

[Nordlys]

Thanks, so what you are saying is you do get less rotation under power.?


I have boats with rudder movements about 90 deg when powered up.


I'm trying to set up a rudder not under power and its just not working out.
N.

[Martin (Admin)]

Doesn't matter is under 'power' or under load, servo will always try to reach the desired angle, called on by the transmitter / receiver.

Remove the link / connection to the rudder, do you get about 180^o?

Does your transmitter have rates?

[HMS Invisible]

Thanks, so what you are saying is you do get less rotation under power.?


I have boats with rudder movements about 90 deg when powered up.


I'm trying to set up a rudder not under power and its just not working out.
N.

I'm saying you will get exactly the same 90^o (+/- 45^o) as before.
The servos in your other boats will also have end stops limiting movement to 180^o.
Until you get full rc powered up you can only assume 90^o at 100% transmitter rate (or span) but later use the removable servo arm and transmitter to trim at the centre.
The receiver makes no difference so you can use any that works with the transmitter.

[Nordlys]

I'm getting the full 180 swing of the servo arm, but by hand only, not 90.
I'll have to wait till I connect up to power so that the transmitter can have some controlling effect.
I've connected up many rudder assemblies before but this one is giving me trouble, I think because I'm trying to set it up without power.


Thank you both.
N

[JimG]

A icrogyros is saying you will get more movement when moving by hand not under power. the electronics are setup to stay well away from the mechanical endstop under power, this is only to protect the servo mechanics if there is a glitch in the signal trying to drive it too far.
Jim

[Nordlys]

Ah! Thank you Jim. I follow your explanation,  moving the arm by hand gives me much more swing, more than I want.


It's just that I'm working on this boat without receiver or transmitter at the moment.


N

[Martin (Admin)]

Mine is rotating full 180 but not under power. Is this correct anyone?

Basically - Yes!   

[Nordlys]

I spent too long in the workshop today messing with this.
Thank goodness for Mayhem  members and Martin.
N.

[malcolmfrary]

The servo will turn to the point indicated by the transmitter stick when connected to a powered receiver.  It will swing as far as it is designed to bearing in mind that not all transmitters offer exactly the same output signals for the same stick movement. 
Hooking any servo to a servo tester will give useful test results, but these almost certainly will not match what the transmitter will give. 
The signal variation that you get from twiddling the tester knob is usually greater than that via the radio - the radio is intended to give a normal swing of 90 degrees which uses the middle 1/3 of the servo pot, leaving an adequate amount of "spare" at each end to allow the same servo to survive different radio systems.
When not powered, the servo can be manually swung as far as its mechanical stops allow.  Powering it from one of these extremes and giving it a signal, (radio or tester) it will drive to whatever position the signal indicates it should be at.

[Nordlys]

A very full explanation, thank you.
I would normally set up the rudder with power connected all round but this time I didn't have the radio nor receiver to hand.
It's been an interesting few posts for me.


N.

[Circlip]

And don't forget, swinging the servo by hand puts a reverse strain on the gear train. Good for b****ring the teeth.

   Regards  Ian.

[derekwarner]

Do you put Colgate on prior to b****ing your teeth?     ...[sorry  rrrrrrrrrrrrrrrr]

[Circlip]

Sorry Dereck, missed an extra * 


  Regards Ian.