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Arming an ESC

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Ron:
Well, you would think there was a vague standard of some sort for servo movement.
Or is that wishful thinking?
If that is the case then the servo specs should say what it is.
Even if it's just a 'recommended maximum' type of thing.
But really it should be relative to the Rx output at 'standard' signal conditions.

How any or all of that might apply to ESCs is another subject entirely.

And there are boat ESCs that have, presumably, off in the centre, and reverse the other way.
Sorry, astern...

Ron

Happy Days:
Just been comparing the spec of a number of different servos. In all cases, when quoting the speed of the servo the specification refers to the amount of time for the servo to move 60 degrees.

I therefore believe that what I read before probably was correct. That the “Standard”, amount of movement of a servo arm is 60degrees. :wink:

Although this is only my speculation, it seems to me that this amount of movement equals the “100%” quoted on Tx’s

Well, it seems rational at least! All interesting stuff you know :?:

K.

Ron:
That's interesting.
So the next project is: Measure some servo angles with the Tx set to 100%.
Across a range of servos and Txs of course.

Ron

Aidan:
There is a standard but it's based on the signal frequency not the movement of the servo. There's a standard centre position which I think all radio brands use (including Multiplex in UNI mode. In MPX mode there's a 9% difference) Different servos may have different max deflections bu the signal range that produces them should be pretty much standard. So full travel on one servo will happen with the same signal input as produces full travel on any another servo. The % thing is just a convention. As far as I'm concerned 100% servo travel is the full range of motion available. However JR, Futaba and probably most radio brands don't treat it that way. They take, say, +/-80% of the actual available servo travel and call that +/-"100%" on their tranmitters. This means if you set up your plane using "100%" throws and then decide you need more you can have another 25% because you weren't really using 100% to start with. As I mentioned earlier , I believe multiplex mean it when they say 100%. If I remember correctly anything over 100% on a Multiplex radio only has an effect if it's feeding into a mixer or is the result of a trim adjustment and it's shifting the relationship to the stick position but not increasing the available throw.....I might be wrong about that last bit!
I recently got a JETIbox and have started using it to set servo centres and check available deflections - very convenient when setting up a model. It allows you control the actual signal value throughout the full range. I can take a look tomorrow evening and see what the actual range is and where the centrepoint lies. I think the standard is 1500ms with a range of +/-500ms but I'm not sure. It might be 1600ms.

Happy Days:
Yea’ I’ve just been reading through my Futaba manual. (All 119 pages of it! :!: )

When referring to the amounts of servo movements available with this Tx (10CG) it says;

• Ranges from 0% (no servo movement at all) to 140%. At a 100% setting, the
throw of the servo is approximately 40° for channels 1-4 and approximately
55° for channels 5-8.
• Reducing the percentage settings reduces the total servo throw in that direction.

That would seem to concur with what you’re saying Aidan. I can’t for the life of me understand why 100% isn’t 100% movement.
And as for why “100%” movement should be different for some channels and not others completely baffles’ me!

It’s never really bothered me. I’ve just set the movements up to the amount I wanted. But looking at the matter from a broader perspective it does seem a somewhat ridiculous way to run a hobby.


Keith

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