Weight?

[mapes12]

Can some one give me some more detail about Weight? The manual says:-

"Weight
This value multiplies the value from the input. It can range from -125% to +125%. Default is 100%."

The reason I'm asking is that I've just fitted out a new model with digital servo's (new ones). With the Weight at 100 (default) the servo's stop moving with about 2mm of stick input to go i.e. they do not move any further with the last 2mm of stick travel. If I drop the Weight to 80 the sticks move to their full deflection and the servo's move with them i.e. I do not get an additional 2mm of stick travel without servo movement, but the servo's do not move any further than when the weight is at 100.

I've unhooked the control surfaces to eliminate physical binding.

Is this a limitation of the servo's perhaps? I don't know.

Mark

[kalle123]

Sorry see, it er9X

[KAL]

Hi Mark,

besides weight there are the limits (which are processed after the mixes).
No matter what (input * weight) is, the output does not exceed the limits (normally 100%).
If you want more than 100% of output you have to enable "extended limits",
only then you can set limits beyond 100%.
But keep in mind that with er9x 100% output equals to 125% compared to Futaba, Jr, etc.

Klaus

By the way: you know this manual?

[mapes12]

Thanks for the reply.

But keep in mind that with er9x 100% output equals to 125% compared to Futaba, Jr, etc.

Why?

[KAL]

When going over 100% of output with some receivers or servos you can get into some trouble
(some channels may interfere / some servos may bind) because of exceeding design parameters
(of TX module, RX, Servo,...).

So when you do this, please check whether everything works OK ...

Klaus

[MikeB]

But keep in mind that with er9x 100% output equals to 125% compared to Futaba, Jr, etc.
Why?

Because Futaba/JR/Spektrum only use 80% of the possible servo throw for normal stick operation and leave the remaining 20% for use by the trims.

Mike.

[mapes12]

But keep in mind that with er9x 100% output equals to 125% compared to Futaba, Jr, etc.
Why?

Because Futaba/JR/Spektrum only use 80% of the possible servo throw for normal stick operation and leave the remaining 20% for use by the trims

That makes sense but does it not conclude that with ER9X we have no "room" for trim? Or should we be setting our Weight settings to 80 where we anticipate trim will be required?

[Kilrah]

The latter if no clipping is important in your application.

[MikeB]

Sort of!
1. If you use some trim, then you will reach the endpoint when moving the stick before the stick gets to the end.
2. If you then copy the trim into the sub-trim (e.g. use instant trim), the trim goes to centre, then the servo movement is then scaled so the whole stick movement is used between the sub-trim point and the end point (limit).
3. If you set a value in "AutoLimits", then the endpoints are adjusted by the sub-trim amount (up to the value of AutoLimits).

If you think you are likely to need some trim amount (e.g. a maiden flight), I recommend setting a switch for "Instant Trim". Then you just need to hold the model straight and level, flick the "Instant Trim" switch, and the S & L position is put directly into the sub-trims.

It is generally recommended that if you have something in the sub-trims, the mechanical linkage should be adjusted so the sub-trims become 0.

Mike.

[mapes12]

Sort of!
If you think you are likely to need some trim amount (e.g. a maiden flight), I recommend setting a switch for "Instant Trim". Then you just need to hold the model straight and level, flick the "Instant Trim" switch, and the S & L position is put directly into the sub-trims.

Thanks Mike. How do you assign a switch to achieve this please? Previously, I have trimmed the model and when landed put the trims to sub trims using the Limits menu. But I don't know how to assign a switch to achieve this?

[MikeB]

In ModelEdit|General it is called "Trim Sw". When this switch is activated, both the stick positions and trims settings are used to set the sub-trims, so really useful if you are needing to hold both aileron and elevator to keep straight and level, flick a single switch and you model is trimmed.

Mike.

[mapes12]

Sort of!
1. If you use some trim, then you will reach the endpoint when moving the stick before the stick gets to the end.
2. If you then copy the trim into the sub-trim (e.g. use instant trim), the trim goes to centre, then the servo movement is then scaled so the whole stick movement is used between the sub-trim point and the end point (limit).
3. If you set a value in "AutoLimits", then the endpoints are adjusted by the sub-trim amount (up to the value of AutoLimits).

Been thinking about this a bit more.

So, are we saying that if the servo's receive an input that goes beyond their movement specification that they go to there max and don't attempt to go any further i.e. don't burn up battery amps trying to get somewhere they were never designed to get to?

As for trims and notwithstanding the 125% v Futaba etc. piece, then let's say max travel in one direction is +100 and in the other -100, my understanding of trim was that if the trim was for example +5, then the servo movement would then default to +95 and the other way -105. I'm sure I've got this wrong but trying to understand it?

[jhsa]

If you are seeing a deadband at the end of the stick movement, I think you need to calibrate the sticks.

João

[mapes12]

If you are seeing a deadband at the end of the stick movement, I think you need to calibrate the sticks.

João

I did that just before I started testing the new model. But I understand the logic. Thank you.

[MikeB]

[As for trims and notwithstanding the 125% v Futaba etc. piece, then let's say max travel in one direction is +100 and in the other -100, my understanding of trim was that if the trim was for example +5, then the servo movement would then default to +95 and the other way -105. I'm sure I've got this wrong but trying to understand it?

That is correct for the sub-trim, but not for the trim.

Mike.