It's a good thing not everyone has the same kind of uneducated views about new technologies as mikhail does as we'd still be living in the stone age if they did.

A3 Pro
I moved the A3 Pro from my Hawksky to my Extreme Flight 540 Edge. I flew my Extreme Flight last fall,winter,spring till a couple weeks ago w/o a gyro and it flew great. Even in the wind, it really does not need the gyro to stay stable. But I'm using it to see how the gyro affects it and is an alternative platform for testing than my Hawksky. I previously flew the Eagle Tree Guardian in the Edge 540 so I can compare and contrast those two.

First off, as mentioned, the A3 Pro has the ability over the A3/i86AP to switch from RATE/OFF/HH mode via a switch. I have mine on a 3 position flap switch. But if you have a TX capable of setting 0% Travel adjust, you can use a 2 position switch and pick the 2 you want.
Also as mentioned above, the Heading Hold mode, wants to see 0 trim in order to know your not moving the sticks. You set this 0 trim mode, by removing the blue jumper and powering it up (as per the manual). So no matter what Tx/RX you have you can program it to not move w/ centered sticks. Here lies the problem as mentioned. It will not only see that as your center stick position, but it also sets the output signals to what it thinks is center (1500-1520uS abouts). So if you were to fly your plane w/o the gyro or were to fly the plane w/ the gyro in OFF or RATE mode, and then touch the trims, once you do the center stick function, the servos will move BACK to a non trim condition. This means that with the A3 Pro you have NO CHOICE but to trim mechanically whenever you want to use HH mode AND either OFF or RATE MODE. If you flew only in HH mode, no problem, It will just like a heli gyro, hold the plane straight. My only caveat on this is that if you were to line up for take off, you better hit the switch to OFF or RATE before taking off in HH mode or the plane may roll/pitch/yaw on you on take off. I spent some time, working on my mechanical trim to get it right. Previously, I've gotten my planes to be mechanically trimmed but usually needed to hit a click or two trim to get it nice and level and that was fine with rate mode, but with HH mode, the A3 does not like trim (note, this is not as much of a problem with the Eagle Tree Guardian, It remembers center stick but keeps the servo output to your trimmed setting when you reset the centering).
Next, I found that in HH mode, the gyro gain dials were MORE reacting different than Rate mode. For example, If I tested for an osciallation condition, the oscillation condition would occur sooner (with a lower gain) in HH mode than rate mode. And in HH mode, the oscillations (occured for me with elevator) were very violent (unlike in the Eagle Tree Guardian where it has the oscillation detection). In order for the HH mode to have any benifit in a torque roll, I had to crank up the gains. If I had the gains lower, the plane response was laggy, and I really need to put in some Dual rates to make it feel comfortable as well. When I did the torque roll, it was MUCH easier than before, but almost to the point of "that's great, but this wont' help me get better at my stick movements to be better at torque rolling". So although, the A3 Pro allowed me to torque roll easier, I dialed back the gain and then ran it in rate mode instead.
So once again, I come back to RATE mode being more "organic" and "natural" than HH mode. Rate mode is more like taking a small plane and making it fly like a big plane. I can sort of quantify this by saying that my friend's 100" wingspan Extra 300 was SOO much easier to torque roll than any of my planes, it made me realize that I was not as bad as I thought if I was comparing myself to people with bigger planes. But w/ my little Edge 540, if I simply have a RATE gyro, I'll be learning the orientation skills needed for a good torque roll w/o having to bring out a big gas planes so I'll get more stick time. (my 48" Edge hangs in my garage and fits in the back of my Yukon w/o taking it apart so I can litterally spend 30 seconds getting into the car and 2 minutes setting it up before I fly allowing me to easily fly before work or lunch break).

Oh, yea, this was asked before, YES, the A3 Pro in Rate mode as well as HH mode will fight the turn some. Less in Rate mode than in HH mode if you keep the gyro gain down.

So I know that some of you have been happy w/ the A3 Pro in HH mode, but for me, I'm gonna recommend people still start out in Rate mode. If I were to keep the A3 in the Edge 540 that is already a VERY stable plane, I'd be flying it mostly in the off postion unless it's excessively windy or I'm practicing my torque rolls.

Here's my 800mm FMS T-28 with the i86ap from HK.

FMS/Airfield 800mm T-28 Trojan w/ Stability System (6 min 48 sec)

Melnic,
Thank you for the excellent review and comparison to the Guardian. I finally really understand. I flew my A3 Pro today for the first time and HH mode was a terrible mess. Now I understand why. I'm going to edit my end points so I never inadvertently turn it on.
Rate mode worked very well. I will need to reprogram my RTH on my DOSD because it no longer has the control authority to turn the plane around.

I had one major problem with my A3Pro. Twice it forgot my gyro reverse settings, and switched back to default directions. The second time I didn't catch it on preflight, and it made for a very scary and confusing flight. When I got it on the ground, and checked the settings, I only saw blue flashes, my red flashes had gone away on their own.
Has this happened to anyone else?

Originally Posted by Herman Munster

It's a good thing not everyone has the same kind of uneducated views about new technologies as mikhail does as we'd still be living in the stone age if they did.

He's also over in the Battery forum extolling the virtues of old-school "Tamiya" battery connectors over the myriad of high-quality, low resistance hobby-grade connectors. I know this is a topic that approaches religion in terms of discord, but I've never met ANYONE that thought the Tamiya connectors were anything but toy-grade crap.

He's either trolling all over the forums, or just has a very particular & esoteric set of firmly-held beliefs, and is unwilling to change them based on empiric data & evidence reported by others. Either way, not a particularly useful source of knowledge on a community forum.

Personally, I'm waiting for the OrangeRX 3-axis to come off backorder. For $15, I'll try them in a couple of my planes at least. Wind doesn't scale properly with the small size of our models, if these do nothing else but help to dampen the effects of wind on lightweight electric models, they're already worth it IMO.

I just recently got my Guardian 3 axis gyro, can't wait to try it out. The plane I'm installing it in is going to the field tomorrow and I'm going to get everything trimmed up mechanically, then the gyros going in. Should be fun.

Originally Posted by Herman Munster

I just recently got my Guardian 3 axis gyro, can't wait to try it out. The plane I'm installing it in is going to the field tomorrow and I'm going to get everything trimmed up mechanically, then the gyros going in. Should be fun.

I really want one of those for my Dynam Peaks Bi-pipe... looks like an awesome product.

Diesel6401: I use the Detrum GY48V gyros on my Dynam Peaks....one for the ailerons and one for the rudder. I see no need for an elevator gyro; which negates a 3 axis gyro. The Rudder is on my DX7 gear switch and the ailerons on the flap switch. Switch them off unless in very windy conditions; sure make the bipe fly like dead calm when all other flyers are grounded. Like cruise control on a car, for those winers. These Detrum gyros are cheap and faultless and I followed the Melnic website instructional videos...what a great value to us mortals! Love that Peak bipe...the best plane I ever owned.

Melnic,

Check it out and only $50

http://www.bluelight-tech.com/index.htm

Hey Prof good find.

That one is a geek's delight. You can adjust just about every possible variable that influences the outputs. Wow!

Originally Posted by jj604

Hey Prof good find.

That one is a geek's delight. You can adjust just about every possible variable that influences the outputs. Wow!

There is even a developer's model for twice the price. May the geek's have a party.

Originally Posted by Diesel6401

Here's my 800mm FMS T-28 with the i86ap from HK.

https://www.youtube.com/watch?v=X6JM...e_gdata_player

Got a pair of those i86 on order to play with. Pretty easy setup?

Originally Posted by RustySpork

Got a pair of those i86 on order to play with. Pretty easy setup?

Yea not to bad. Go on HK website and find the product and click the "files" tab towards the bottom and find the instructions and the amendment. Read the amendment first because theirs a mistake in the instructions regarding output leads and the amendment calls out that mistake.

Originally Posted by Prof100

Melnic,

Check it out and only $50

http://www.bluelight-tech.com/index.htm

Got one on the way to me. i'll report when I get it in.

Originally Posted by Melnic

Got one on the way to me. i'll report when I get it in.

I look forward to your analysis and report.