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Old 02-17-2016, 09:05 AM
davestapa davestapa is offline
Join Date: Apr 2007
Location: Woodstock, GA
Posts: 29
Default Dynon & Vertical Power Issue

We have a RV-10 that has Dynon SkyView and VP-X installed. We have talked to Dynon & Vertical Power about an issue with the trim indicator. We have loaded the VP-X Configurator and set limits to 1 as instructed and did the trim settings in the SkyView. The trim indicator on the screen shows up, but the arrows are either at the top or bottom of the scale and do not move with the trim changes. Dynon says it's a VP-X issue and Vertical Power says it needs to be corrected on the SkyView settings. Anyone else have this issue, or have any ideas.
David E
Woodstock, GA
RV-9A N97KE Rehomed
Kitfox 5 N97DE Grounded
RV-10 N96KE Flying
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Old 02-17-2016, 10:45 AM
rleffler's Avatar
rleffler rleffler is offline
Join Date: Jun 2006
Location: Delaware, OH (KDLZ)
Posts: 4,224

I have a different vendor's EFIS and a VP/X unit.

The trim monitoring is just reading the resistance of a potentiometer.

I would recommend taking your own reading with a VOM and both full and down trim positions.

I would then ask Dynon if there is a debug mode in which you can tell the value of the data they are receiving from the VP/X.

Chad should be able to tell you what the VP/X outputs based upon your resistance measurements. Then you should have enough data to tell where the problem may be.
Bob Leffler
N410BL - RV10 Flying
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Old 02-24-2016, 11:42 PM
BruceP BruceP is offline
Join Date: Feb 2007
Location: Bakersfield, CA
Posts: 220

Dave, I have the same problem and received the same answers from Dynon and Vertical Power. However, I didn't really pursue it any further and now I have just learned to trim by experience. The only time I wished I had it was at takeoff but I have solved that primarily by learning to count how long to hold the trim down button after a landing. Trimming up while landing is the most my trim moves on any flight and I've gotten pretty good at getting the trim right for takeoff and I don't really miss not having the indicator.

I actually have the same issue with the flap indicator but when I did my transition training with Mike Seager he taught me his technique. He only uses two flap settings, half and full. Half flaps for me on downwind is a four count, and another four count to full flaps on base. It has worked wonderfully and I have no need for the indicator.

Would it have been nice to have the elevator trim indicator show me the takeoff setting? Yeah...but I'm perfectly happy counting to three now.
Bruce Peters
Bakersfield, CA
RV-9A, Flying 11/21/15
Donation up to date 08/20
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Old 02-25-2016, 12:03 AM
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bruceh bruceh is offline
Join Date: Mar 2008
Location: Ramona, CA
Posts: 2,423

I had an issue with the VP-X +2.5V power pins on J1 not putting out any voltage. It is easy to check with a voltage meter. If the poteniometer in the trim unit doesn't get any voltage it will always report the same value (in my case 0) for any position. I ended up sending the VP-X back for repair and that fixed it.
Bruce Hill
RV-9A N5771H flown over 800 hours!
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Old 02-26-2016, 04:07 PM
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KRviator KRviator is offline
Join Date: Oct 2009
Location: Sydney, Aust.
Posts: 823

Another question for the guru's here before I start trouble-shooting after the weekend?

Yesterday I went out to condition the brake pads and do a fuel calibration before the first flight. The engine started fine, if a little slow to catch, but it hasn't been started for awhile, and the Dynon dimmed during cranking as you'd expect but recovered fully. However, being the knucklehead I am, I forgot to turn on the alternator, so all ground-ops were discharging the battery to the point it gave up the ghost during the fuel cal and the Dynon shut down.

I sourced another battery, started fine, and got back to the hangar, but the Dynon would not come back online, and I appear to have lost control of the flaps, driven through the VP-X.

Given, the P-Mags powered up and I was able to start the engine suggests the VP-X is working, as they're powered through that, but the loss of the Dynon and flap control indicates otherwise.

I can understand if the loss of flaps is related to the loss of ASI data from the Dynon, but any other ideas to consider before I head back up to the hangar on Monday?
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Old 02-26-2016, 06:41 PM
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MCA MCA is offline
Join Date: Jun 2005
Posts: 706

Regarding the incorrect trim (and flap) indication issue:
Assuming this is the initial configuration, and not a situation where "it was working once but is not working now", it is likely a wiring issue. Please try this:
- connect the VP-X configurator to the VP-X and go to the trim or flap page. There you will see several numbers, one of them indicating the current trim or flap position.
- Command movement of the trim or flaps, and you'll see the "current position" number move consistently as the motor is running.
- If the number does not move steadily between roughly 0 to 255 as the motor runs, then the wiring to the position sensor/servo is incorrect.

If the number is not moving, then the indicator on the EFIS will not move as well.

Regarding the low battery:
- connect the VP-X to the configurator on your PC.
- look to see if any of the circuits are faulted, then reset them. The low battery condition causes the amperage to rise, sometimes tripping a circuit.
- also turn on/off the circuits from the configurator (and move the flaps) to confirm they work

Hope that helps.
Marc Ausman
RV-7 980 hours, IO-390, VP-X (sold)
RV-8 (flying a friend's)
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