Auto trim in simplified mode
- Thread starter DonFromTX
- Start date
Raymo
I love aviation!
This came up in another thread where Dynon responded with:
"have you gone through the Auto-trim configuration under SETUP > HARDWARE CALIBRATION > TRIM MOTOR CONFIGURATION?"
"have you gone through the Auto-trim configuration under SETUP > HARDWARE CALIBRATION > TRIM MOTOR CONFIGURATION?"
Carl_Froehlich
Active Member
- Joined
- Aug 22, 2007
- Messages
- 323
No.
The AP panel has no function other than being a trim servo relay is you are in the simplified mode. I sent a note in to Dynon on this that while the installation manual clearly states you must be in the expert mode for any of the AP panel function to work, this point was missing from their product advertising. They have since added this caveat.
I'm not fan of the expert mode and on my last plane I have the Safety Trim instead of the AP panel (done before the AP panel came out). I installed a dual SkyView in a new RV-14 and this is when I discovered the issue. The next plane will have the AP panel so either Dynon does a software upgrade to make it work in the Simplied mode, or I'll learn to like the Expert mode.
Carl
Actually, the autopilot auto-trim feature DOES work in simplified mode. None of the on-device buttons function in simplified mode, though.
Really?...So if you are saying that Autotrim works in 'Simplified' mode what about speed scheduling? I thought that speed scheduling only works in Expert mode with Autotrim. Are you also saying that speed scheduling also works in both modes 'Simplified' and 'Expert'? What about trim speed scheduling when when autopilot is not engaged at all?
I need some clarification please, the manual is not clear enough I think on this.
- Joined
- Mar 23, 2005
- Messages
- 13,226
Page 18-9 of the install manual says:
So that seems pretty clear that the auto trim functions work with any AP mode.
As for trim control and speed scheduling, the install manual doesn't mention AP modes at all in that section. That's because manual trim control and speed scheduling works even if you didn't have autopilot servos at all. It's completely independent of the autopilot, and manual trim works even if SkyView fails. We can see how that omission could be confusing, so we'll clean that up in a future revision, but rest assured that trim control and speed scheduling work if you have the AP control panel installed no matter what the configuration of the rest of the system is.
As a clarification as well, speed scheduling has nothing to do with autotrim. The whole point of speed scheduling is so you get about the same amount of trim force change per second of manual button operation at all airspeeds. When the system auto trims, it follows its own rules about moving the trim tabs and doesn't follow the speed schedule since it can command the trim for very short periods of time and doesn't need to worry about human reaction speeds.
So that seems pretty clear that the auto trim functions work with any AP mode.
As for trim control and speed scheduling, the install manual doesn't mention AP modes at all in that section. That's because manual trim control and speed scheduling works even if you didn't have autopilot servos at all. It's completely independent of the autopilot, and manual trim works even if SkyView fails. We can see how that omission could be confusing, so we'll clean that up in a future revision, but rest assured that trim control and speed scheduling work if you have the AP control panel installed no matter what the configuration of the rest of the system is.
As a clarification as well, speed scheduling has nothing to do with autotrim. The whole point of speed scheduling is so you get about the same amount of trim force change per second of manual button operation at all airspeeds. When the system auto trims, it follows its own rules about moving the trim tabs and doesn't follow the speed schedule since it can command the trim for very short periods of time and doesn't need to worry about human reaction speeds.
Speed scheduling is the real glory of the knob panels even if you stay in simplified mode.
In the case of the RV-12, the Vans trim controller is a one-setting gadget. Using the Vans default setting makes for trim so fast, it's impossible to trim hands off in pitch no matter how short you jab the trim switch. On mine, I slowed down the controller to less than half the Vans start point, with only partial success. And then, the trim speed on the ground or in the pattern was glacially slow.
The Dynon variable pitch trim controller allows you to vary the trim speed, slow to fast, to match the airplane's speed, slow to fast. On the ground and in the pattern, I get zippy trims. In cruise, I get nice slow trims. Much better - but not perfect.
If you set the high speed trim too low (below about 25%), on my airplane, it will stall the (Ray Allen) trim motor. So the trim controller will do it, but the trim motor won't. I'm assuming it varies the voltage to the trim motor.
Cruise trim is now much better manually, but still no cigar - the RV-12 is very sensitive in pitch.
Carl: You should try and learn the Expert mode. It's not hard and a joy to use. I couldn't live without it. Even without the AP engaged, you have control of all your settings and bugs.
Bob Bogash
RV-12
N737G
In the case of the RV-12, the Vans trim controller is a one-setting gadget. Using the Vans default setting makes for trim so fast, it's impossible to trim hands off in pitch no matter how short you jab the trim switch. On mine, I slowed down the controller to less than half the Vans start point, with only partial success. And then, the trim speed on the ground or in the pattern was glacially slow.
The Dynon variable pitch trim controller allows you to vary the trim speed, slow to fast, to match the airplane's speed, slow to fast. On the ground and in the pattern, I get zippy trims. In cruise, I get nice slow trims. Much better - but not perfect.
If you set the high speed trim too low (below about 25%), on my airplane, it will stall the (Ray Allen) trim motor. So the trim controller will do it, but the trim motor won't. I'm assuming it varies the voltage to the trim motor.
Cruise trim is now much better manually, but still no cigar - the RV-12 is very sensitive in pitch.
Carl: You should try and learn the Expert mode. It's not hard and a joy to use. I couldn't live without it. Even without the AP engaged, you have control of all your settings and bugs.
Bob Bogash
RV-12
N737G