Virtuall flybar for AP applications?

[MarkWebber]

edit

[MarkWebber]

I had my workbench chair between me and the heli

:lol:

I understand the feeling, Mark. I half expected mine to be an out of control monster during the first spool up. I used my Jeep :roll:

Worked good right?

[MarkWebber]

:arggg:

[oscillator]

Worked good right?


Once I got over the nervousness of having a 30 size heli with no flybar right in front of me and in a tight space, it seemed to work fine. I only had the skids an inch off the ground, and kept it there for maybe 5 seconds at a time.

My garage is my work shop - no cars - so there is stuff every where. I had at most 2 feet in any direction before a blade strike. :shock: Needless to say prop wash was creating all kinds of proximity effects. But once I calmed down it seemed to work just fine.

I'll take it outside today for some real hovering and play with the gains. Provided there are no major problems or mishaps I'll clean up the wiring a bit tonight and take it to the field tomorrow for some real flight testing.

I must say the AP2000i had been supper easy to set up thus far, and the carbon case matches my Carbon Logo 10 perfectly! Here is hoping for a rock solid hover.

[MarkWebber]

I had at most 2 feet in any direction before a blade strike. Needless to say prop wash was creating all kinds of proximity effects

Mark, you sure take flight testing to the limits, huh? :D

[oscillator]

Took a brake from work and hovered the heli in the driveway. Aside from needing lots of aft and left trim (guess the swash wasn't level), it flew just like a normal heli. There was some wind but the heli didn't mind much. My tail was kicking out a little on pitch pumps, even with 80% gain on the tail gyro in HH, but I suspect I have too much delay dialed in.

I maneuvered the heli around and flew little circuits, keeping the tail more or less pointed toward me the entire time. If something went wrong or it got difficult to handle I wanted the simplest possible recovery. I did not notice any roll/pitch interaction and stability seemed fine.

Here is the setup:

Carbon Logo 10 w/ Mikado flybarless head
Mikado 500mm wood blades (wasn't going to risk carbons yet)
GY401 w/ 9254 on tail. stock tail and tail blades
JR DS4321 servos on swash.
Servo Linkages at 13.5mm (Mikado specs 19mm when using flybar).
approx 7% max pitch. Only generates a few deg pitch at max cyclic.
GY240's for roll and pitch stabilisation. Set at approx 25% gain (trim pot). No dealy setting available on 240's. ACVS (HH) off.
Z30A-800 w/ 19T pinon, Phoenix HV-45 ESC and Dewalt 10 cell A123
AP2000i used for eCCPM mixing only (no IR sensor). CCPM Mix set at 50% (default).
Checking for phasing adjustment, I can just barely notice a pitch change when the rotor is over the tail and full fore or aft cyclic is given. I plan to adjust this out later, but left it alone for now as it was barely perceptible.

I was very pleased with the result - esp since I haven't done any tweaking yet. Once I get it dialled and streatched out it should be a great camera platform. Can't wait to try the IR sensor.

[GGoodrum]

This sounds great. It will be interesting to see if there is an efficiency improvement that yields longer durations.

-- Gary

[MarkWebber]

Awesome results, Mark. You're going to love it with the stabilization activated!

Less daunting than it seems, isn't it? :D

[oscillator]

Less daunting than it seems, isn't it?


Mark,

Trivial is the word that comes to mind now that it is in the air :D. Honestly didn't expect it to be this easy.

Couldn't resist the good weather this afternoon and took the heli out to a large vacant parking lot. I only have 1 functional A123 pack at this point (2nd pack had a spot welded tab brake off and thus far I haven't been able to solder it back), so testing was limited.

I found that everything is smooth and solid up until about ~60% gain on the 240's. After that it starts to get the shakes. I have the gain at about 50% now for pitch and roll. I attribute my higher gain setting to two factors:

1. GY240 vs GY401
2. significantly shortend servo linkages (13.5 vs 19mm)

I'm hoping to fly tomorrow with a buddy who has a Logo 10 (with flybar). If so, I'll let him fly my flybar-less Logo and tell me how it feels in comparison.

Tonight I'm going to level the swash and clean up the wiring. Maybe I'll play with the phase adjustment. Who knows, might even get the stabilizer on.

Gary,

Yes, I'm curious to see the durations as well. Today there was too much start and stop to get a good run time. I also need to check the head speed - throttle curve is still just 0-100% linear. Probably way too fast.

Wound up taking 2350mAh out of my pack today. Recharged in 31min on the TP1010C/210 at 5A. Too bad it won't charge at 10A.

[MarkWebber]

1. GY240 vs GY401
2. significantly shortend servo linkages (13.5 vs 19mm)

I'd be curious to know what difference is allowing the higher gain, too. Not that it would affect my flight characteristics. My servo linkage went from 18mm to 8mm.

I did find settings in G3 for the ION-x that feels alot like my R50 so I can play with the handling on the sim. I did put my R50 in and broke a blade on an outside loop. I just think it was me with poor cyclic/collective management at the bottom of the loop and just ran 'er out of headspeed. :roll: Maybe I need a 90 :D

[oscillator]

Testing didn't go so well today......

Got the wires cleaned up (well, most of them) last night, leveled the swash, installed the IR sensor and got it set up and verified. Did my little hover in the garage again - at 2:30AM. :shock:

Took it to the field this AM, plugged in the battery, did a quick control check, put the canopy on, and spooled up. It kept trying to tip over to the left. Upon inspection I realized one of the servo leads had pulled out due to a poor crimp job. Back home and on the bench - inspect and carefully re crimp and test the servo leads.

Back out to a local park for a quick flight. As I carry the heli out I'm on the phone with Spork discussing what time to fly tomorrow AM. Radio on, correct model, normal flight mode, throttle low, throttle hold on, plug in the battery - and the servos valiantly try to do their job, but the blade holder wins. :oops: :arggg:

Note to self - multi tasking makes you stupid!

Unfortunately non of the local shops stock gear sets for JR DS4321's. Looks like Horizon has the nylon in stock, but I'll have to wait until March for the metal ones.

So much for flight testing this weekend.

[kgfly]

Are you flying Spektrum, if so this could be the first documented case of a cellphone preventing a Spektrum equipped system from flying :lol: :lol:

I say blame Spork and make him pay :twisted:

[MarkWebber]

I say blame Spork and make him pay

Interesting conclusion. :)

[oscillator]

:lolol
Now that you mention it, I can't think of any incidents I've had when Spork wasn't there.

[oscillator]

Back in the air!

Wind is blowing good today - fairly gusty, prob 15-20kts. No time to go to a park, so I did some tests in my front yard.

Flew my Trex for a benchmark. I could hold position, but not altitude as the gusts caused it to jump up and down by as much as 2 ft. Flew out and back a few times, nose in, tail in, some turns, piros, etc. There isn't much room and with the wind I wasn't going to try more.

Spooled up the Flybarless Logo 10 (still stock 500mm woodies) and hovered it into the wind. No problems, very steady. I wasn't trimmed out perfectly, but it was pretty stationary and very solid. Maneuvered around a bit - the wind was noticeable, but no big deal. Flew great.

Then I turned on the stabilization. Since I don't have a slider I can only set my gain using endpoints. I had preset the gain to 80%. Wow. Hands off stable. My CAL wasn't perfect so I had some slight drift - but wow! I can't wait to take it out and really fly it.

Don't know if I will get a real flight in before this weekend or not. And I don't have a flybar Logo 10 for comparison, but so far I am impressed.

Next step is to dial in the head speed. Can someone point me to an optical tach that can be used in flight? I have a cheap Hanger9 unit that requires you stand right over the rotor - not exactly safe.

[dreslism]

Next step is to dial in the head speed. Can someone point me to an optical tach that can be used in flight? I have a cheap Hanger9 unit that requires you stand right over the rotor - not exactly safe.

Cool you're back in the air. I take it you did not talk to spork today? :wink:


Well, I don't have anyone to help me try one for in flight, but I take a roll of duct tape or packing tape, lay it on it's side under the blades, then stick my hobbico optical tack in the center of the big ole roll of tape pointing up.

Then spool up. I can stand quite a ways off to the side and read the tach.

Just make sure you slide the roll of tape holding the tach so it is under the blades, but not too far under that it also reads the flybar or it will throw your reading off.

Oh wait, that's right, you don't have a flybar anymore.... :mrgreen:

[MarkWebber]

Glad to hear you're Spork-free...I mean back in the air :D

Flew mine again today, also. Not as windy and warmer, finally! First time I really got to try out the HH side. Almost like having the IR stabilization active. Tracks a bit better than rate mode and ballooning was almost nil. Hands off stable also but not for as long as with the IR.

Oh wait, that's right, you don't have a flybar anymore

And yet another benifit is revealed :D

[MarkWebber]

Oh, and this is the tach I prefer. Wish I had bought one of these instead of the model avionics unit. Even unexperienced helpers are able to use it easily. I can't say the same of the one I bought. It is pricey but worth it.

[rerazor]

I just use vice grips or a small C-clamp to hold/balance the tach on the ground.

Put away the duct tape Scott. :mrgreen: :twisted:

[dreslism]

I just use vice grips or a small C-clamp to hold/balance the tach on the ground.

Put away the duct tape Scott. :mrgreen: :twisted:

Hey, it's always in the car, or the packing tape is always in the toolbox from my airplane days.

[GGoodrum]

I have a small mini-tach and it fits in a blade holder. :)

Interesting Mark, so you are now using the HH mode on these? I guess in this case HH can meen "Hover Hold". :)

Angelos, how is your testing going with your new gyro? I would love to see an integrated AP-2000i with these new gyros. Flybarless AND inertial-based stabilization. Is this in the cards? :)

-- Gary

[oscillator]

Hi Mark,

could you post the model name/number or a link to the tach above? The pic is only a small thumb and doesn't expand, so I can't read anything off the image.

Scott, rerazor,

A very wise man once told me "if it can't be done with duct tape and c-clamps, it can't be done." I guess he has proven right once again.

[MarkWebber]

Sorry for the bad pic...didn't check my post. It's the Miniature Aircraft brand. I'm not sure of the model number. Heliproz has them.

Gary,

I tried out HH on a few of my previous flights but the combination of wind and shaking from the cold didn't allow me to realize any benifit vs. rate mode. I am pleased with the results.

Reguarding flybarless with the ds760...I feel just certian that Angelos will hurry some on the way to me when they are ready. :wink: And if you'd like to have a peek at the new gyro...check it out here.. http://www.spartan-rc.com/
Can't wait to ditch the 401's in favor of the ds760's

I did discover the cause of the oscillations I have been experiencing at the end of every flight. I thought it was pilot input due to the cold. It was not that cold yesterday, yet the oscillations were present as I was coming in to land. Turns out it's settling with power that is to blame. I was able to duplicate at will and avoid by not settling with power. I'm not sure if that can be tuned out with the gyro's. Maybe with a better quality gyro and/or servos.

[oscillator]

Just ran a quick test over lunch. My cheapo tach indicates about 2300 RPM, but my calculations show about 2000 RPM. Hard to say as the reading was jumping all over.

The wind was quite gusty again - worse than yesterday. I hovered for a solid 12 min on a 10 cell A123 pack before detecting a power reduction. There was no camera or mount on the heli.

I suspect my head speed needs to come down to about 1800 RPM. The 19T pinon may be too large as I'm already at 80% throttle curve.

With the head speed dialed in I'm hoping to get about 10min w/ reserve carrying the camera and associated gear.

[rerazor]

12 min on a single 10s1p 2300 a123 is pretty impressive.