Trimming FBWA mode

Hi, first post and I’m sure this is a simple overlook on my part.

I am trying to get the numbers correlating to trim in rc calibration screen to read 1500. However because I have the aircraft trimmed for manual flight the numbers are not 1500. Specifically my pitch is at a higher number because the aeroplane is slightly nose heavy.



Hi Justin,

A suggestion is to use different trims for the different modes you are flying. If you can save your trim values (or at least write them down), then set them back to 0 on the TX. Then do the calibration so that you get 1500. Then for your manual mode (and training mode) set them to your previous values.

I use opentx and when I fly my manual trim and my FBWA trims are separate. I have my stabilized modes using one set of trims and my manual (and training modes) using a different set.



OK. Thanks Chris.
The only issue I have with that is say for example I am using FBWA for take off and for some reason, I need to change into manual very quickly I would be changing to a mode that I am not trimmed for. This would possibly be a situation when I am close to the ground. My transmitter requires me to use two hands to trim and it is not exactly fast.

I am actually considering purchasing a Accu Throw Control Surface Deflection guage as pictured below and using it to manually adjust my trim on the aircraft so my trim is centred on my tx and therefore the numbers read 1500. Just an idea anyway, Interested to know what you think.

Thats the point I’m making, with OpenTx (running on a taranis 9xd+) you can have a set of trims per flight mode or in my case I have two sets of trims that I use (one for stabilized and one for manual / training modes). So when you flip the switch it changes them in software.

Can I ask what Tx are you using? That would help a lot in coming up with a solution that would work for you.

The gauge you referenced there is good for aligning the surfaces to the wing, that may not be your trimmed position though. It will be dependent on your CoG to be honest. Having said that its good practice to get them as close as possible for efficiency but not the end of the world if its out by a small bit (unless your going for max endurance or speed). Then you’d need to play with your CoG to get it perfect - often close enough is good enough- dont over think it is my recommendation.


Ahh ok I see now. Not familiar with OpenTx, I have been out of the hobby for a few years now and I am gradually catching up on the newer technology. I am still using a JR10X, which limits me from getting the openTx firmware. Thank you for your info. Much appreciated.


I’d suggest you try the SERVO_AUTO_TRIM option. It will automatically adjust the servo trim values while flying so that if you switch to MANUAL it will have correct trim.

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Ok great. So the flight controller will actually hold the trim within its own settings? Is there a way to see what it has changed?

yes, look at SERVOn_TRIM. Those will be slowly changed when flying to push the integrator towards zero. It only does roll and pitch trims, not rudder