ALign APS setup?

[Delarado]

Hi guys,

not sure if anyone will have seen these yet but ive been helping a friend set his up.

we got the 3gx dialled in nicely on a 700 converted from FB to FBL, although something is a bit off. The link lengths are already all shorter than the standard lengths (just the ones from swash to head and swash to bell cranks) but the pitch is still showing +2 at mid stick with the servo horns level. He is using semi symmetrical blades - is this the reason? I dont want to shorten the lengths any more as they are all already 3-4 mm shorter than the manual says.

Added to that during the APS setup it says to check swash compensation by moving the heli up and down and checking the swash moves in the opposite direction (i.e move heli up swash moves down)

The swash doesnt move when you move the heli up or down. We have checked the APS shows the correct mode when you move the gyro gain switch to select APS, GPS or 3GX mode. It just doesnt seem to compensate the pitch for up and down movement, everything else works properly.

Also, when you switch to aps or gps mode with the heli on a flat surface, the swash seems to creep forward and right elevator until it goes the whole way. Put it back into 3gx mode and it levels out again - but in APS or GPS the swash creeps gradually and we are worried to fly it.

any help appreciated!

[cjcj1949]

Have you tried adjusting the altitude gain?

[Delarado]

no... didnt even get that far! Its just set as the default at the moment...

[Delarado]

The swash didnt seem to move at all though...

[cjcj1949]

In the manual it says the swash doesn't move very much. It says you can put your finger on the swash to feel it move up and down. Thinking about it you don't need much movement to correct a small slow change in altitude. I think I'd try a new system out on a cheap 450. The creep may be ok as that is the sort of thing you sometimes see on heading hold servos and shows small errors that the system shows because the airframe is not able to respond to the control changes. You could try moving the airframe in the direction of the drift and see if the drift goes as it does with a HH servo. My cheapo Assan 250 doesn't drift at all. Probably due to Apple using units like this in their phones.

[Delarado]

Any comments on the pitch issue with semi symmetrical blades?

[cjcj1949]

I would think that semi blades would upset the controller. I'd assume that until someone else showed that it didn't. You will get different lift compared to a normal blade, just as you do with a plank. If the software is up to it it should ask for the blade type. If it is really good then it could work it out for itself. It depends how common semi blades are.