guide to set up the TRIM

Every time I run into a mess when create a new model and down to the part of setting up the TRIM. It is just a hit and miss and never understand the logic behind the Trim Menu.

Can any one explain what "Input" refers to? and the "TRIMLH+" series means?

I sit down and think why on earth that makes the TRIM function so complicated?

What is TRIM? It is just a simple temperory and convenient means (ONLY to be used during a flight) to compensate any residual mis-centering wherever it is due to the stick, servo, push rod alignment or any other mechanical setting up etc. during a flight. That sort of compensation SHOULD be corrected in a proper way after landing and so the usual park of the TRIM should be ZERO.

In this regard, Trim is very simply. Moving a trim should in effect moves the corresponding stick position by a tiny amount in the same stick direction. Nothing more, nothing less and disregarding how many complicated mixers in behind the cyclic stick. The only thing that a Trim needs to be set up is the Step.

Sorry for my ignorance. Should there be any clever use of the Trim that I have missed, please point it out to me...

I'll chime in as well.

First, I'm sure you are a heli flyer. Helis, with the exception of fixed pitch do not use trims so much. Fixed pitch helis though usually cannot be setup 100% mechanically. Especially cheaper ones.

Planes on the other hand use trims actively during flight. A plane has different flight envelopes depending on the amount of throttle used and need to be actively trimmed throughout the flight.

This happens with full scale planes too, because of the wing angle of attack a plane usually climbs after a certain amount of throttle is applied, so you need to trim down elevator to keep the plane flying horizontally.

More to this, a plane is much harder to setup mechanically than a helicopter. Helis have metal and carbon fiber and hard plastic as materials. Planes not so much. Lots of foam and wood. Sometimes flexible materials like tape hinges and thin push rods.

I hope I cleared things up for you, just remember things aren't as simple as you think

FDR wrote: I will try to explain:

The trim buttons, just like the other controls (like switches and sticks) can be assigned to do more then one thing.
By default they are assigned to work as trims for the sticks, but they could be assigned to be independent "analogue" inputs on their own too.
The assignment is done the following way: you choose to which input (stick, channel, etc) the value will be added, choose the buttons: where "TRIMLV-" means left vertical down button, while "TRIMRH+" means right horizontal up button.
The trim step is trivial, I think...

You usually don't even have to touch this config, because they are configured as trim buttons according to the tx's stick mode by default...

Thanks for your explaination. Now that I am able to tackle how it works.. However:

1. The default is in the following order (using Mode 1, right hand Thottle): ELE, THR, RUD, AIL. It seems that the order must be stictly followed. That is if I reorder the sequence, everything will be a mess.

2. With the default, all the displayed trimming are ok in the Main page.. BUT not the output. I have to change the defaulted "INPUT" to CH2, CH3, CH4 and CH1 for the ACTUAL output to take effect. SO should they be called "Output" instead of "Input" ?

3. I have not try out yet, but even so, will the Trim add or subtracts the Channel outputs directly and bypassing all the mixing that have delibrately set on the stick?

4. Any means I can do one of the most simple thing to my transmitter, that is "trim the stick"?

5. As a side note, being a R/C pilot for over ten years, I still can't see why, the Trim being one of the most indispensable function in R/C can be scarcified in any way for other functions.. to the least, the default should work AND a warning be poped out should a user really tries to make change to it...

thanks again for your patience...

cmpang wrote:
5. As a side note, being a R/C pilot for over ten years, I still can't see why, the Trim being one of the most indispensable function in R/C can be scarcified in any way for other functions.. to the least, the default should work AND a warning be poped out should a user really tries to make change to it...

Can you reformulate this part? I have a hard time understanding what you are trying to say.

What's complicated about this part? Looks simple and straightforward to me...

ha ha..

the default works as in its default form.. mine doesn't work after I have carefully follow the settings in the dafault page and key into my model.

So it is even more confusing.. why with the same setting and it doesn't work for me? May be I have to put more time in the programming ...

I am a Heli as well as a Plane pilot.. a R/C boat captain, a R/C battle tank commander and a R/C submarine as well. None of my R/C can the trim be dispensable..













i,setting to key in my model. So it is now even more confusing..

cmpang wrote: ha ha..

the default works as in its default form.. mine doesn't work after I have carefully follow the settings in the dafault page and key into my model.

So it is even more confusing.. why with the same setting and it doesn't work for me? May be I have to put more time in the programming ...

I am a Heli as well as a Plane pilot.. a R/C boat captain, a R/C battle tank commander and a R/C submarine as well. None of my R/C can the trim be dispensable..

i,setting to key in my model. So it is now even more confusing..

Try increasing the step. Default can be very small with some servos.