Adjusting pitch trim rate.

Just started the Production Acceptance Package. Had to reverse the the wires for the trim tab-- thanks for the good explanation, Mel. With a trickle charger hooked to the battery it takes 23 seconds for full trim tab travel. "Nominal" is 25-30 seconds. I KNOW there's a section in the instructions on adjusting the pots for all the functions but I'll be darned if I can find it! Anyone working thereabout who can refresh my memory? And can the panel be slid out far enough to work on it or do I need to pull the panel cover off.

After a couple of trim cycles the battery starts to drop off. Joe (Van's) thinks that a trickle charger isn't doing the jpb on the Odessey Battery. Comments??

THANKS!

So close and YET so far.

Wayne 120241

I don't think you could get to the pot without removing the cover over the panel. Having said that, per Ken at Vans you can adjust the trim rate pot with the left inst panel in place after removing the top cover. I found it easier to pull the left panel so I could see what I was doing. I have found that the numbers in the manual have a "fudge factor". Mine is set at 23-24 seconds with Vans approval. Any slower and it really strained. I can't remember who I spoke to on that issue, but it wasn't the first time they said the numbers were subject to a little variation.

Pot

Wayne,

The pot is down at the bottom of the circuit board and impossible to get to unless you take out the circuit board and turn it on its end. 23 seconds may sound a tad quick but if you've flown it and are comfortable with quickly punching the switch to do your adj you will be fine and I'm sure Van's will agree with it.

Adjusting the trim pot

I'm also trying to adjust this. Mine is currently working VERY slowly, even with an external 13.4 volt supply. Can anyone advise which way to turn the pot screw to increase the rate - clowckwise/anti-clockwise?

Thanks...Keith

gblwy said:

I'm also trying to adjust this. Mine is currently working VERY slowly, even with an external 13.4 volt supply. Can anyone advise which way to turn the pot screw to increase the rate - clowckwise/anti-clockwise?

Thanks...Keith

Click to expand...

I found that because the adjustment screw is so difficult to get to they made the adjustment somewhat backward to further frustrate. To make the motor run faster you have to adjust the screw counterclockwise. On my first try I thought it would be like most adjustments and turned it clockwise which made it even slower. Be careful not to turn it too far, there is a warning in the instructions that it is possible to turn it too far, and have to turn it back to get operation.

Tony

How much?

So far, I have not succeeded in getting the time from stop-to-stop below 50 seconds. Any idea how many turns there are on the pot to go from its stop-to-stop? I cannot see if the screwdriver is just slipping or whether it is really turning the pot. I feel as if I have gone a long way anticlockwise...

Cheers...Keith

gblwy said:

So far, I have not succeeded in getting the time from stop-to-stop below 50 seconds. Any idea how many turns there are on the pot to go from its stop-to-stop? I cannot see if the screwdriver is just slipping or whether it is really turning the pot. I feel as if I have gone a long way anticlockwise...

Cheers...Keith

Click to expand...

Hi Keith,
I had to take out the screws holding the circuit board so that I could raise it slightly. Then using an inspection mirror I was able to see the screwdriver slot in the pot and insert a small screwdriver. I think the pot movement is less than 1 turn stop to stop. Be careful.

Tony

Trim speed adjustment & EFIS trim position display

Shut off the master switch while adjusting the pot so that the screwdriver does not short out the circuit board. The pot is turned C-CW to increase the speed. There is about 3/4 of a turn from stop to stop. You can practice by adjusting the transponder pot at the top of the circuit board and getting a feel for how far it turns and the force required, which is very little with only two fingers on the screwdriver. I was able to adjust my trim pot by removing the screws holding the left panel, then raising the whole left panel. Doing that allows room to get your hand under the EFIS and also allows the screwdriver to be at a 90 degree angle to the circuit board. It is almost impossible to adjust the pot without loosening the panel because the handle end of the screwdriver hits the panel base and causes the other end to miss the slot in the pot. If the trim tab does not move at all, it is probably because the pot is adjusted for too slow of a speed. In that case, a helper can hear a faint whine at the motor. The speed will not change due to varying voltage that is above 12vdc because there is a voltage regulator in the trim circuit. So the trim circuit only sees 12 volts even if a battery charger is putting out 14 volts or whatever.
There are 3 settings that need to be made in the Dynon setup in order to see the trim position on the D-180.
1. INFO ITEM CONFIG, ITEM 7 = TRIM POS
2. EMS GP INPUT 3 = FUNCT: TRIM ELEV
3. Calibrate as described in the FlightDEK-D180 Installation Guide page 6-6.
Joe

I also had to remove the screws and lift and tilt the panel. Another good suggestion is to use an insulated/non-conducting screwdriver or put some tape on the shaft. It slips off the pot easily and you then could short a board trace to ground.

Thanks

Thanks guys for useful feedback on adjusting the pot. I'll have another go. I found out the hard way to switch off the master or use an insulated screwdriver. I now have a pile of dead fuses ;-)

Cheers...Keith