Align APS Questions - and wowes

[phaselag]

Hey Guys,

After a weekend of head scratching & countless attempts at setting up the Align APS for a friend of mine, I finally got it to work as it should. I thought it would be beneficial to share my process with others who may have issues getting the APS to function correctly.

Firstly, follow the elementary steps of the manual when setting up the 3gx and APS.
The Trex 500 is running a cc esc and I'm used to running governor mode with the set RPM function enabled and therefore flat throttle curves on my DX8. I was a little annoyed that align stressed the fact that you had to run linear throttle & pitch curves for the APS in normal mode. As it turns out you only need the linear throttle curve to initially calibrate the APS/3gx after which you can set to suit yourself. My throttle curve is a flat 30 in mode 1, and 70 in mode 2. Reflecting head speeds of approximately 1600 & 1800rpm respectively. Pitch curves are linear in both modes with -12 - +12 degrees of pitch.

I believe The biggest factor that contributed to the APS on the heli initially not working properly was vibrations. After many attempts at passing the vibration tests I eventually got it to pass (without changing anything). Once it had passed the vibe test (which was perhaps a lucky run) I ruled out the fact that vibrations would cause any issues.

After many attempts of changing things based on trial and error I was unable to get the APS working properly. It would do random things such as rapid un-commanded ascents and descents. I packed it in for the day and took the heli home. Upon inspecting my mates mounting of the APS unit it turned out that he had used basic thin double sided tape (not the included tape). I got hold of some thick foamy double sided tape and remounted the unit. I carried out the vibe test in both head speeds and it passed every time. I concluded that although I had it pass the vibe test earlier, there were still intermittent vibes from the heli causing havoc with the APS unit.

The following day I took the heli out, carried out my checks lifted in to the hover at around 50 feet, switched in to APS mode and it worked flawlessly. You are probably thinking, what an idiot of course its going to be sensitive to vibrations. Yes, however I thought that the sensitive vibe test was to ensure the best accuracy of the unit and lets face it all helicopters vibrate to some degree. I didn't expect it to not work at all.

Anyway in summary, when installing the APS make sure that your heli is running as smooth as possible and your APS is mounted with appropriate cushioning. Carry out the vibe test and make sure that it can pass consistently because any vibe that will cause it to fail the test, may result in the APS making erratic manoeuvres in-flight.

I should also mention that even though I'm ruining flat throttle curves, I am still able to utilise the semi-autonomous take off and landing feature.

The APS is a great little unit and I'm excited to see what is to come from align in the future.