Van's Air Force
Don't miss anything! Register now for full access to the definitive RV support community.
RV-12: Dynon Trim Calibration
- Thread starter Geico266
- Start date
Jetguy
Well Known Member
Trim Calibration
Enter the EMS menu by pressing any button below an EMS main page and pressing MORE > SETUP > MORE > TRIM. The TRIM CALIBRATION menu shows AILERON, ELEVATOR, and RUDDER, followed by the GP input that each is configured as (or NONE, if no GP input is configured for a given axis). Ensure that this list corresponds to the physical connections made during the setup described in the Trim and Flaps Position Potentiometers section on page 3-16.
During the calibration process, the onscreen instructions will direct you to put the trim into various positions, pressing NEXT after each change. The calibration process allows you to set a takeoff trim position; this position is displayed as a green line on the trim scale info item. During the calibration process, ensure that the number shown in the VALUE field changes as you adjust the trim. If the number does not change, the trim sensor may be incorrectly wired to the FlightDEK-D180, or incorrectly configured in the GP input selection under the SENSOR menu. At any point in the process, you may press CANCEL to end the calibration without overwriting the previous calibration results. Once you are ready to calibrate, select the desired trim that you would like to calibrate, and press SEL► to enter its calibration menu. Press the RANGE button to begin calibrating the range of the trim. Follow the onscreen instructions, controlling trim to the required position before pressing NEXT. Repeat the process for the opposite position. The process will then prompt you to put the trim into takeoff position. If you do not require a takeoff indication on the given axis? trim display, you may press NONE. When you have completed the calibration, press the DONE button.
Press the TAKOFF button to calibrate the takeoff position indicator. When calibrated, a green line is displayed on the trim scales, indicating takeoff position. View the trim display on the EMS Main or Aux page (depending on where you configured it to display) to make sure that it works as expected. You may repeat this calibration process as many times as you wish.
Page 6-6 in Dynon instalation manual for D-180
John
RV12 N1212K
Enter the EMS menu by pressing any button below an EMS main page and pressing MORE > SETUP > MORE > TRIM. The TRIM CALIBRATION menu shows AILERON, ELEVATOR, and RUDDER, followed by the GP input that each is configured as (or NONE, if no GP input is configured for a given axis). Ensure that this list corresponds to the physical connections made during the setup described in the Trim and Flaps Position Potentiometers section on page 3-16.
During the calibration process, the onscreen instructions will direct you to put the trim into various positions, pressing NEXT after each change. The calibration process allows you to set a takeoff trim position; this position is displayed as a green line on the trim scale info item. During the calibration process, ensure that the number shown in the VALUE field changes as you adjust the trim. If the number does not change, the trim sensor may be incorrectly wired to the FlightDEK-D180, or incorrectly configured in the GP input selection under the SENSOR menu. At any point in the process, you may press CANCEL to end the calibration without overwriting the previous calibration results. Once you are ready to calibrate, select the desired trim that you would like to calibrate, and press SEL► to enter its calibration menu. Press the RANGE button to begin calibrating the range of the trim. Follow the onscreen instructions, controlling trim to the required position before pressing NEXT. Repeat the process for the opposite position. The process will then prompt you to put the trim into takeoff position. If you do not require a takeoff indication on the given axis? trim display, you may press NONE. When you have completed the calibration, press the DONE button.
Press the TAKOFF button to calibrate the takeoff position indicator. When calibrated, a green line is displayed on the trim scales, indicating takeoff position. View the trim display on the EMS Main or Aux page (depending on where you configured it to display) to make sure that it works as expected. You may repeat this calibration process as many times as you wish.
Page 6-6 in Dynon instalation manual for D-180
John
RV12 N1212K
The trim tab actually operates the stabilator, not the aircraft.
When the tab goes up, it pushes the trailing edge of the stabilator down, thereby pushing the nose of the airplane down.
When the tab goes down, it pushes the trailing edge of the stabilator up, thereby pushing the nose of the aircraft up.
When the tab goes up, it pushes the trailing edge of the stabilator down, thereby pushing the nose of the airplane down.
When the tab goes down, it pushes the trailing edge of the stabilator up, thereby pushing the nose of the aircraft up.
Mel is right. You can set the 12 up the way you have described but you don't want it that way when you're flying. It is more natural in the air to push the button the way you want the nose to go (push to top half to go down etc). As Mel said, about half of us had it hooked up backwards when he did our inspections. I can honestly say I was the first...and now I'm glad he had me change it.
Jetguy
Well Known Member
Trim on Dynon
Mel did my inspection to. And my anti servo tab moved the correct direction but the indication on the dynon was backwards. He noticed this on the inspection. While he was there we did the trim calibration again on the Dynon. When you do the calibration on the Dynon the directions that are depicted on the screen will lead you to set it up backwards. If only Dynon would add just a few extra words on the screen when doing the procedure. Like the word "Elevator". You will understand when you read the directions on the screen.
John
RV12 N1212K
Mel did my inspection to. And my anti servo tab moved the correct direction but the indication on the dynon was backwards. He noticed this on the inspection. While he was there we did the trim calibration again on the Dynon. When you do the calibration on the Dynon the directions that are depicted on the screen will lead you to set it up backwards. If only Dynon would add just a few extra words on the screen when doing the procedure. Like the word "Elevator". You will understand when you read the directions on the screen.
John
RV12 N1212K
Dynon
No wonder you had the Dynon instructions up so quick when Larry asked for them...lol You're right, the wording is not as direct as it could be. Makes sense now!
By the way, I got so busy with my wheel pants and other stuff that I haven't even tried the AP download you sent me. Have you? Did it work?
No wonder you had the Dynon instructions up so quick when Larry asked for them...lol You're right, the wording is not as direct as it could be. Makes sense now!
By the way, I got so busy with my wheel pants and other stuff that I haven't even tried the AP download you sent me. Have you? Did it work?
Stabilator trim calibration
Doing the calibration per Dynon p6-6 the 'value' number never changes. Servo wired correctly, and output voltage varies with trim tab movement. The white arrows along side of the panel icon showing trim tab setting just keep 'bouncing' up and down...nothing that can be wiggled, shaken, tapped on, pulled or pushed, airframe rocked, etc, changes that ... the white arrows on the side of the tab position icon just keep jumping up and down..never stop. Full stop-to-stop tab takes about 25-seconds, reliably changing as panel switch commands. GP#3 used for tab input. Rechecked over and over as were servo wires...Dynon tech support not much help only suggesting a wiring error, which has been ruled out over and over.
Your guess ?
Doing the calibration per Dynon p6-6 the 'value' number never changes. Servo wired correctly, and output voltage varies with trim tab movement. The white arrows along side of the panel icon showing trim tab setting just keep 'bouncing' up and down...nothing that can be wiggled, shaken, tapped on, pulled or pushed, airframe rocked, etc, changes that ... the white arrows on the side of the tab position icon just keep jumping up and down..never stop. Full stop-to-stop tab takes about 25-seconds, reliably changing as panel switch commands. GP#3 used for tab input. Rechecked over and over as were servo wires...Dynon tech support not much help only suggesting a wiring error, which has been ruled out over and over.
Your guess ?
VERIFYING WIRING FOR PITCH TRIM POSITION INDICATOR
Shut off the master and avionics switches.
Remove Dynon D-180 from panel and unplug cables.
Take resistance measurements on the EMS 37-pin female D-Sub connector as follows:
Resistance from airframe (ground) to pin 18 (white / red wire).
Resistance from airframe to pin 23 (purple / green wire).
Resistance from pin 18 to pin 23.
The resistance from pin 18 to ground should be about 5k ohm, plus or minus 10 percent.
The other measurements will vary, depending on the trim position, but should be somewhere between 0 and 5k ohm. None of the measurements should be changing with the trim tab stationary.
John, you said that the voltage varies with the trim position. Are you measuring from the airframe to the white / green wire at the servo? If so, that indicates that two of the three wires are good. But that voltage might not be getting to the Dynon pin 23. The above resistance check will verify that the signal is getting to the Dynon. If there is not a wiring problem, then my guess is a software problem or interference from some other device.
Let us know what you find.
Joe
Shut off the master and avionics switches.
Remove Dynon D-180 from panel and unplug cables.
Take resistance measurements on the EMS 37-pin female D-Sub connector as follows:
Resistance from airframe (ground) to pin 18 (white / red wire).
Resistance from airframe to pin 23 (purple / green wire).
Resistance from pin 18 to pin 23.
The resistance from pin 18 to ground should be about 5k ohm, plus or minus 10 percent.
The other measurements will vary, depending on the trim position, but should be somewhere between 0 and 5k ohm. None of the measurements should be changing with the trim tab stationary.
John, you said that the voltage varies with the trim position. Are you measuring from the airframe to the white / green wire at the servo? If so, that indicates that two of the three wires are good. But that voltage might not be getting to the Dynon pin 23. The above resistance check will verify that the signal is getting to the Dynon. If there is not a wiring problem, then my guess is a software problem or interference from some other device.
Let us know what you find.
Joe
Trim Calibration
Joe, here is what I found:
Power off to D180
Looking into the plug on the end of the cable that goes into the D180:
Pin 18 reads 585-ohms to ground
Pin 23 shows an open..no continuity to ground, no voltage present
Pin 18-to-pin 23 reads an open, no voltage.
Calibration attempts never moves the "value" number from 500
The white arrow heads at the side of the trim icon showing where the trim tab is set, keeps jumping up and down. No matter if on internal D180 battery or with charger connecte to plane's buss, no difference if anything else is on or off, or if any combination of things on the instrument panel are on or off.
Output from Ray Allen servo varies from zero to 5 v when tab moved full up to down; it varies, as an example, from a setting of, say, 3.05 volts and moves from 3.05 to 3.06 but not in synchronism with the 'arrow heads' on the tab setting icon. I even tried turning off all the lights in the hangar, no difference.I removed the large slip-on connectors at the servo and temporarily tack soldered the wires together that go forward from the servo..no difference. Those wires are correctly connected; right color to same color.
The only thing I can think of that I have not yet tried is to pull the D180 and examine the potentiometer that sets the trim movement...it sits rather awkwardly at the hole through which you can adjust the trim movement, and maybe, maybe, that's somehow involved.
I can't recall if I pulled the 37-pin connector from the D-180 to see if the trim tab position indicators 'bounce' without that plug installed or not. Will do that in a few hours.
Other than that I am out of ideas.
Joe, here is what I found:
Power off to D180
Looking into the plug on the end of the cable that goes into the D180:
Pin 18 reads 585-ohms to ground
Pin 23 shows an open..no continuity to ground, no voltage present
Pin 18-to-pin 23 reads an open, no voltage.
Calibration attempts never moves the "value" number from 500
The white arrow heads at the side of the trim icon showing where the trim tab is set, keeps jumping up and down. No matter if on internal D180 battery or with charger connecte to plane's buss, no difference if anything else is on or off, or if any combination of things on the instrument panel are on or off.
Output from Ray Allen servo varies from zero to 5 v when tab moved full up to down; it varies, as an example, from a setting of, say, 3.05 volts and moves from 3.05 to 3.06 but not in synchronism with the 'arrow heads' on the tab setting icon. I even tried turning off all the lights in the hangar, no difference.I removed the large slip-on connectors at the servo and temporarily tack soldered the wires together that go forward from the servo..no difference. Those wires are correctly connected; right color to same color.
The only thing I can think of that I have not yet tried is to pull the D180 and examine the potentiometer that sets the trim movement...it sits rather awkwardly at the hole through which you can adjust the trim movement, and maybe, maybe, that's somehow involved.
I can't recall if I pulled the 37-pin connector from the D-180 to see if the trim tab position indicators 'bounce' without that plug installed or not. Will do that in a few hours.
Other than that I am out of ideas.
Brantel
Well Known Member
The reason your indicator is bouncing around is because the input is floating or not connected to anything or the input circuitry is fried inside your D180. This would be normal in the case where an input is configured for an indicator but there is nothing connected to that input. A wire connected to the actual pin but left floating on the other end will cause the indicator to flop around....
Here is a horrible quality video I made with a cell phone to show Dynon a issue I had with my system. On this video starting at 1:14 you can see my indicators doing what you describe. The reason mine were doing this at the time was because my harness was not connected to the servo or the flap position indicator at the time, just hanging in space.
http://www.youtube.com/watch?v=pzFy9Ru4wrI
Here is a horrible quality video I made with a cell phone to show Dynon a issue I had with my system. On this video starting at 1:14 you can see my indicators doing what you describe. The reason mine were doing this at the time was because my harness was not connected to the servo or the flap position indicator at the time, just hanging in space.
http://www.youtube.com/watch?v=pzFy9Ru4wrI
Last edited:
open circuit
John F,
From the resistance readings, I am 100% sure that there is no continuity from Dynon pin 23 to the center of the trim pot. The pot itself is ok because you measure a voltage from the center of the trim pot to ground, right?
Here is the circuit:
Dynon pin 23, purple/green wire to EFIS pin 5 on control board, to FUSELAGE pin 4 on control board, white/green wire to center of servo potentiometer. Somewhere along that path the circuit is open. Although it is possible that a wire is broken, more likely is a bad connection at an end. Or a wire could be plugged into the wrong hole on a D-Sub. If you are sure that all connections at the servo are secure, then the next step is to check the connectors on the back of the control board.
Unplug the FUSELAGE D-Sub connector.
Make sure the white/green wire is in hole number 4.
Check continuity from pin 4 back to the tail. If open, check wire connection to pin.
If that is OK, then remove the cable that goes from the Dynon D-180 EMS to the control board and check both ends of the purple/green wire for security and to be sure that they are plugged into the right holes. Measure continuity from pin 23 to pin 5.
If that is OK, then measure continuity on the control board from EFIS pin 5 to FUSELAGE pin 4. If that is bad, then the easiest repair is to bypass the control board by plugging the white/green wire directly into the Dynon D-180 EMS D-Sub 23 hole. But it is highly unlikely that the control board is at fault.
Sometimes wire connections look good, but the wire can be broken inside of the insulation. Tug gently on the ends wires to see if the wire comes lose or stretches.
Let us know what you find. I predict there is a broken wire in a D-Sub connector.
Good luck,
Joe
John F,
From the resistance readings, I am 100% sure that there is no continuity from Dynon pin 23 to the center of the trim pot. The pot itself is ok because you measure a voltage from the center of the trim pot to ground, right?
Here is the circuit:
Dynon pin 23, purple/green wire to EFIS pin 5 on control board, to FUSELAGE pin 4 on control board, white/green wire to center of servo potentiometer. Somewhere along that path the circuit is open. Although it is possible that a wire is broken, more likely is a bad connection at an end. Or a wire could be plugged into the wrong hole on a D-Sub. If you are sure that all connections at the servo are secure, then the next step is to check the connectors on the back of the control board.
Unplug the FUSELAGE D-Sub connector.
Make sure the white/green wire is in hole number 4.
Check continuity from pin 4 back to the tail. If open, check wire connection to pin.
If that is OK, then remove the cable that goes from the Dynon D-180 EMS to the control board and check both ends of the purple/green wire for security and to be sure that they are plugged into the right holes. Measure continuity from pin 23 to pin 5.
If that is OK, then measure continuity on the control board from EFIS pin 5 to FUSELAGE pin 4. If that is bad, then the easiest repair is to bypass the control board by plugging the white/green wire directly into the Dynon D-180 EMS D-Sub 23 hole. But it is highly unlikely that the control board is at fault.
Sometimes wire connections look good, but the wire can be broken inside of the insulation. Tug gently on the ends wires to see if the wire comes lose or stretches.
Let us know what you find. I predict there is a broken wire in a D-Sub connector.
Good luck,
Joe
Trim Calibration Problem
Joe and Brantel, you were correct. I did not find any loose wires or pins pushed out of place, so I finally took Joe's suggestion and just bypassed the control board. That got everything working correctly. I calibrated the trim per the Dynon install. manual
One area of uncertainty though: The calibration has you set the trim for take off, but I guess you are supposed to know where that is. I have the heavy green horizontal line in the middle (vertically) of the trim display icon, and the tab indicators at 2/3rds up from the bottom half as another poster suggested.
I appreciate the help. I doubt I'd have solved this without help. Thanks again.
JohnF
Joe and Brantel, you were correct. I did not find any loose wires or pins pushed out of place, so I finally took Joe's suggestion and just bypassed the control board. That got everything working correctly. I calibrated the trim per the Dynon install. manual
One area of uncertainty though: The calibration has you set the trim for take off, but I guess you are supposed to know where that is. I have the heavy green horizontal line in the middle (vertically) of the trim display icon, and the tab indicators at 2/3rds up from the bottom half as another poster suggested.
I appreciate the help. I doubt I'd have solved this without help. Thanks again.
JohnF
Good going John
Good going John fixing the trim display. Glad I could help. Having a control board makes it easy for builders to plug and play the electrical system. The disadvantages are more cost, slightly more weight, and more connections that introduce more failure points into the system (as you discovered).
Joe
Good going John fixing the trim display. Glad I could help. Having a control board makes it easy for builders to plug and play the electrical system. The disadvantages are more cost, slightly more weight, and more connections that introduce more failure points into the system (as you discovered).
Joe
