Align APS on AP Heli

[HedgeHeli]

I've been building a 700e camera ship. The flight control is with the Align APS unit. Before adding the gimbal I flight tested the APS and it does exactly what I wanted. Yesterday I flew for the first time with the gimbal and a dummy camera I guess the all up weight to be around 7-8kg. When I swithched into APS the heli did not have enough lift and so just descended.

I tried a few things like raised ATT gain which helped slow the descent but still did not give enough authority to maintain position. I also moved the GPS unit but at seemed to have no effect.

My base set up is

700e
400kv motor
690 3G blades

Today I will try 2 things, first is to raise the pitch at mid stick. I will go up in 1 degree increments until I hit 3 or 4 degrees. My belief is that the pitch control in the APS unit is limited such that at 0 degrees pitch at mid stick the unit can only go to say +-3 degrees and with all the weight of an AP rig there is simply not enough range for the unit to maintain a steady hover. The next thing I will try are my 710 semi symetricals and see how they work - they have more natural lift than the 3G blades.

[mpnchar]

hi,

how's your experience with Align APS.. ?

Thanks..

[HedgeHeli]

Hi, on a standard heli it flew great and did exactly what it should. Now though I have it on an AP heli and I am having issues as stated above.

I have had some success using semi symetrical blades and upping the mid stick pitch to 1 degree but I think that I have some other issues.

I have the GPS unit sat between two batteries and so can't rule out interference. I have a slightly warped autorotation gear and as I lower the head speed this is more pronounced -- although it still passes the vibe test.

I am sure we will get there :-)

[HedgeHeli]

Got it sorted, the pitch range is very very small to get this Unit working. I've switched back to the 3G blades, this time 1 turn on the main blade link rods was not enough, whereas 2 turns made the heli just go skywards, so I did 1 turn then ran through the DIR set up and raised the 3 cyclics using sub trim. This nailed it. Heli still needs tweaking but both attitude hold and GPS return to home now works. This is with boom mounted batteries and a heli weighing around 7-8kgs.

I expect the semis will be ok but have yet to test them.

Cheers all

[Titusx]

Thanks for posting your progress, I am really interested on how Align APS performs.

[jhamlinjr]

Does your swash move upwards when you switch from 3gx to APS? Trying to find this out before my first test of the GPS. Flies great in 3gx mode but nervous about going into APS.

[R_Lefebvre]

Why does the APS have such limited range of collective pitch? That seems a bit non-nonsensical. How does it retain altitude when leaned over? What happens when the battery level drops and headspeed goes down, requiring more collective? What happens when wind comes and goes, affecting translational lift causing it to rise or fall?

I can't believe you have to adjust your mechanical setup.

[HedgeHeli]

Originally Posted by R_Lefebvre

Why does the APS have such limited range of collective pitch? That seems a bit non-nonsensical. How does it retain altitude when leaned over? What happens when the battery level drops and headspeed goes down, requiring more collective? What happens when wind comes and goes, affecting translational lift causing it to rise or fall?

I can't believe you have to adjust your mechanical setup.

Aileron and Elevator seem to have full authority but pitch is a very small range. If you check the instruction manual during pre-flight they suggest you lightly rest your finger on the swash while moving the heli up and down and that you will be able to "feel" the counter movement this is because unlike ail or elev you can't see it.

[daruq7]

That doesn't sound very good...

[R_Lefebvre]

That's rediculous.

[yeehaanow]

Seems like something that could easily be fixed with a firmware update??
If it's meant to be used on heavier AP birds then you would think they might've tested it???

[R_Lefebvre]

Yes, sure. I just have to wonder what on earth they were thinking? Forget AP, how is the heli supposed to deal with translational lift changes from wind?

I guess it's just another example of a flight control system posting a video which only shows the best performances and isn't realistic at all.

[HedgeHeli]

I've tweaked it a bit more (mechanical) and it's holding well. I was testing in gusts of 25-30mph (measured on site) and it was able to hold position albeit with some oscillation with the big gusts. Return to home worked flawlessly. I took a risk with this unit but have to say right now I feel OK with it. When the wind calms down I will get to see how stable it can hold.

[alexsmith]

Hi!

We have an APS fully set-up (3GX version 3.0 and APS version 1.2). Already did some flight testing and the results are getting good (no crashes up to now), but not excellent.

Heli doesn't really holds position. It starts fine, but then start wagging the tail a little bit and changes direction, drifting away, but not really fast, so I was able to go back to 3GX and assume control.

Another interesting thing is that the response to transmitter commands is very slow while in APS mode. Something related to the APS screws, I believe... We need to fine-tune it.

We're still testing, without the gimbal for now.

How's your experience going?

[alexsmith]

Hi, guys!

After the last fly test, I can say I got APS working and stabilizing as expected.

Still some further tests to do, but I believe we're on the right path.

If you're interested in knowing more about the configurations I used, just keep in touch, preferably through the forum, so that everybody can make use of the replies.

My current setup is:

Align T-Rex 800 with 3GX
Align APS module
Spektrum DX8 TX/RX