Hoverfly AH. To foam or not to foam?

[Webheadfred]

AH. To foam or not to foam? -- SOLVED!

Hey Gang,
Been reading a few posts and my Y6 is so dang stable, I never really noticed. But I engaged AH and noticed the Y trying to hold altitude, which it did within 3 feet or so. This morning it was dead calm and with the throttle curves, it held altitude and position naturally. Flipped AH and it moved up and down pretty good. Seemed to get a little better with a couple of AH gain adjustments but not as good as without. I think I read where some aren't using the piece of foam if their barometer is shielded from the sun. Would this help? I'm charging now and wanted some thoughts before i went out and dumped her.

 

[Stacky]

Yeah the sun will affect the AH if it hits the barometer. My frame plates cover my board so I dont need the foam but others have used the foam and its helped.

 

[JZSlenker]

Yup, use foam and a blackened enclosure and you will get good results once your gain is setup.

 

[Webheadfred]

Yeah... Had a fly before work and it was just ok. On the radio the endpoint for the gain was up to 130 on the futaba. I took the foam off for this one. Gonna put the foam back on and have a little better shield for next hop.

 

[Webheadfred]

I'm beginning to have an issue with AH. I've completely gone through the ESC calibration with the transmitter on each ESC individually, radio throttle endpoint adjustment using the HFP setup utility, and the HFP built-in ESC calibration all at once. I can find a point with everything turned off(AH,AL,PH) and in dead calm wind, it'll hold altitude. Once I switch AH, it'll surge up and down 4-8 feet. I've adjusted gains up and down. Seems to get a little better higher up but I've reached the max on the Futaba 8FG super and the setup client said a gain of 135 or so. I'm thinking my battery may be going bad and I may try a new one, trying to eliminate things. A question for y'all. When you do the temperature calibration, do you remove the foam from the pressure sensor? I've flown with and without foam and it's shielded from the sun. Any thoughts? I'll try to get a video up showing it.

 

[Webheadfred]

Just had another hop. Had it holding nicely in manual. Perfectly level about 20m in the air. Still air. Then it just started descending and I tried to see if it would correct itself but I had to intervene. My battery is only 6 months old. Could the internal resistance be causing issues this soon? I'm thinking a drop in voltage is causing the descent. It's so smooth and level and then it'll just drop or even climb. AH has the motors surging and struggling to hold.

 

[Webheadfred]

Well after about 15 flights and wanting to completely rebuild, I was was beginning to think I had a battery issue. Then something dawned on me last night watching the Mars landing mission. It didn't have anything to do with my thought, but it's what I was thinking and couldn't wait for daylight to test.

In all my multi-rotor experience, I thought, hmmmm... set the altitude hold gain to the same for the main gain. Good starting point I thought. Well it held 'OK' and surged up and down a little...and then a lot.

So, I think, the gain must be too low! So I keep adjusting it up, and up, and up and down, and down. And the I thought I'd be clever and put a mix on the gain channel to a knob so I could adjust it on the fly. Still, i got unsatisfactory results. It was so smooth in manual mode, I hadn't really noticed or cared earlier.

So last night, it dawned on me that my starting point was way too high. I kept adjusting it higher and higher looking for the 'shuddering' indicative of too high gain. It didn't happen. I was expecting the Y6 to get jittery, and not noticing that the motors were getting jittery bu surging up and down. This actually made it very difficult to fly. Imagine that.

So I started really low, just like the manual says, and took to flight. I got it level manually in dead calm air, flipped the switch, held my breath, and hmmmm..it was a 'what the heck' moment to say the least. I landed and adjusted it a few times and settled on a nice spot on the gain. It holds beautifly!

So note to self, just when you think you've got it figured out, keep figuring. You probably will!

 

[JZSlenker]

Glad you got it working!

 

[PaNt]

ANd whats your Gain now??!

 

[JZSlenker]

PaNt,
gain is irrelevant to compare from one bird to another. The only way you could do so is if you were comparing two identical ships. I'm talking totally identical. Shape, esc, motors, props, batteries, weight. A high or low gain value (or medium) is not bad or good. It's just a number for you to see and adjust for your personal ship. Just start low (as fred discovered) and increase slowly.

 

[Webheadfred]

Before....gain in setup was 95.. I had it at 130 on the futaba.... It's now down to 44 on the radio and I haven't checked it on the setup client but I suspect it's around 50 or so....