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Dynon slip/skid ball

gblwy

gblwy

Well Known Member
Hi,

The only trim adjustment my plane required was the addition of a small 3" x 1" rudder trim - bent left, so right trim.

I believe the plane now flies in trim at 100 knots. However the slip ball is maybe half-a-ball off to the right. The Dynon support forum doesn't indicate any way to adjust this to match the (perceived) actual performance.

Any thoughts on what to do, if anything?

Cheers...Keith
 
Half-ball-out

Hi Keith, wondering how you were able to perceive that the aircraft is in trim. I know you have some round gauges in your panel, including a turn/slip indicator?

I think if the ball on the Dynon is centered with the aircraft at rest on a level surface, then if it is half-a-ball off in flight the aircraft is slipping. But I could be wrong ;).

Tony
 
Has anyone asked Dynon if the ball can be adjusted a bit? With my RV-12 perfectly level side to side, the ball is not centered, the right edge of the ball hits the right side line.
 
MartySantic said:
Has anyone asked Dynon if the ball can be adjusted a bit? With my RV-12 perfectly level side to side, the ball is not centered, the right edge of the ball hits the right side line.
Click to expand...

Marty,
I searched the Dynon forum on this question out of curiosity. The Dynon support moderator states in this thread that the ball cannot be adjusted except to reposition the unit level in the panel. If the ball is between the lines like yours, I wouldn't bother, except to make a mental note, fly and enjoy :p.

There might be enough clearance in the mounting tray to shim one side of the unit up a bit. It would not take much. If so it could be an easy fix.

Tony
 
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more trouble than it is worth

Marty,
Below is a quote from Dynon that I found someplace on the web a long time ago. I think that the ball being slightly off center is something that we have to live with unless we want to re-level the Dynon mounting bracket, more trouble than it is worth.
Joe
Before you go and re-cut a panel, grab a level (digital or liquid) and put it on the bezel of the D100 and see if it reads level. If it doesn't, then you probably have a hangar or gear that aren't perfectly level. If it does read level, then we might want to take a look at it.

The reason we don't have a "zero" on the ball is that the math folds into all the other AHRS math and isn't easy to implement. Overall, we haven't had many issues with this so it hasn't rated as worth it.

Roughly speaking, a half ball deflection is about 2 degrees, while a full ball is close to 4. It takes about 3/4 degree to get the ball start crossing one of the lines, and just tenths to get it to be non-centered.

The sensors that are reflected as the inclinometer are inside the EFIS itself. We calibrate each unit here, so there are two possibilities: either the unit is installed slightly tilted, or the unit is out of calibration. We're happy to take a look at the unit under warranty to help you figure out which it is. Historically, though, just about every unit that has come back for this problem has checked out OK here.
Click to expand...
 
Try the yarn trick

One thing I've done for flight testing is to tape a piece of yarn on the canopy. Good indication of slip/skid, AND it's a bit more responsive than the Dynon indication (there's a bit of latency in the presentation)
 
Thread drift:

Mike can you PM me details of your 7 that's for sale? I know someone looking.

End drift.
 
To check the indication of the "ball", hang a weighted string in the cockpit. If it remains in the original hanging position when maneuvering the "ball" should be centered.
 
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