Problem-Dynon trim display

[woodmanrog]

Well, here's a tough one. The trim readouts on our Dynon D1000 displays are not able to be set up correctly. We have contacted both Ray Allen and Dynon and they seem to be stumped. The indicators read the green take-off positions to the far right of the indicators. We have done the calibration procedures as instructed but nothing changes. As we move the (elevator) from full up to full down, the voltage only goes as far a 5V while the elevator keeps moving to it's final stop. Is there a way of upping the voltage reading or changing the green line to a center take-off position that we are missing? Perhaps someone else has had this same problem and knows the cure. Both elevator and aileron are acting the same way so we doubt very much that the problem lies with the servos. Thanks in advance.
Roger

[Ron B.]

Roger, can you tell me the physical location looking at the elevator trim tab , for the takeoff position? I seem to recall the indicator on the factory demonstrator's Skyview fairly low on the scale for the takeoff position. I will have to go out and check mine to see if it reads travel thru it's full motion, I certainly thought it did (Skyview also).

[Ron B.]

Just went out and checked mine and the last (about) 1/2 inch of nose down travel does not appear to show on the screen indicator. Is this what you are experiencing also? I will have to investigate this tonight.

[woodmanrog]

Thanks for the quick reply Ron. The trim indicator is not moving at all. The green line stays in the far right position through the whole travel of the elevator trim and the ailerons. The trim motor works fine and there is complete up and down. It's just the indicator that isn't moving. Perhaps you could check in SETUP MENU-HARDWARE CALIBRATION-EMS CALIBRATION and then relate back to me what the voltage range is on your (or anybody's)Dynon system. Ours tops out at 5 volts.

[lr172]

Have you confirmed your wiring is correct twice? I believe the Ray Allen trim motor uses a simple linear pot. 5 volts (from D100) in on one end, ground on the other and the output to the D100 (GP #) on the center output. Improper wiring could cause this.

You can also disconnect the ray allen and test it to isolate your issue. You measure resistance across the wires. I believe it is a 10K ohm pot. There are three sense wires (I don't remember the colors, but there in the manual). Resistance across two should always be 10K. The resistance value across the other two combinations will be an equal split of 10K. example:

A - C = 10K
A - B = 2K
B - C = 8K

the two variable readings should go from 0K / 10K all the way to 10K / 0K across the range of travel.

If you put 5V on one end and the output on the other end instead of the center, you would the behavior your seeing. The calibration tool should also be showing you different numbers at different travel points if wired correctl.

Larry

[Ron B.]

When back out on my lunch break and on the elevator I have 4.99 V full down and 0.00 V full up. The reading stops at 4.99 V (I would expect it to) but the actual elevator trim is only flush with the elevator trailing edge. It still travels up perhaps almost 1/2" more with no voltage change.
The aileron Voltage reads 4.85 V rt wing up and 0.00V rt wing down.
Hope this helps , let me know what you find out as mine appears to be working better than yours but is not working as I would expect or like.
Thanks Ron

[woodmanrog]

Again, thanks Ron and Larry. Our system was wired by Steinair so I am not familiar with how it was done. When I bring the plane back up to Sebastion to do the next oil change and fuse panel update, we'll check out all options and suggestions the Vansairforce network come up with. I know we'll get it right.

[n82rb]

the actuator uses a simple voltage divider. you should see about 0 volts at one end of extension and 4.99V at the other somewhere around 2.5V the tabs should be about centered in its arc.
if you are not getting any movement, the voltage is staying constant. there is a wiring problem.

the indicator lines should be driven by the 5v output from skyview NOT 12V from the battery. if you are using ships power, you will see 0 to 12V on the output but skyview will clamp it at 5V so you will see max voltage at half range not full range.

one end of the pot should be tied to pin 18 red/white of the skyview and the other end tied to one of the ground lines. the center tap should be tied the input of skyview the manual suggests pin4 blue/purple for the elevator.

run the motor through its travel and find the center of it movement. a ruler will easily tell you the mid point of the travel. you should see about 2.5V on the line at this point. that can be read from the skyview sensor screen. rig your trim tab to be neutral at the point. you should have pretty close to even throws then. after that run the calibration again.

bob

[lr172]

Originally Posted by n82rb

run the motor through its travel and find the center of it movement. a ruler will easily tell you the mid point of the travel. you should see about 2.5V on the line at this point. that can be read from the skyview sensor screen. rig your trim tab to be neutral at the point. you should have pretty close to even throws then. after that run the calibration again.

bob

Do a bit of research before installing the servo centered at neutral trim. Each airplane is different, but I use a LOT of nose up trim and very little down trim. Mine is set up for about 2/3 travel for up trim and 1/3 for down trim.

Larry