Virtuall flybar for AP applications?

[GGoodrum]

I was about to say the same thing. :)

-- Gary

[oscillator]

Well, grounded again!

Fortunately it was raining outside so I was just hovering in my garage. I kept hearing a strange noise, but assumed it was the rotor wash blowing stuff in the garage. Out side and up high I doubt I would have heard anything.

I should note that I purchased this heli from a fellow Helifreak who had not completed the assembly. I took apart and re-assembled 90% of what he did. Since I was planning on stretching the tail and installing the CF tail upgrade I had left the tail alone - as assembled by the prior owner.

If you haven't guessed by now - one of the tail blade grips let go (yep, there was no thread lock :shock: ). As the heli was only inches of the ground it was easy to set down without further incident. However the damage was impressive.

The blade grip that let go was destroyed, no trace of the fastener or bearings. Tail shaft bent, pitch slider broken, tail servo rod bizarrely deformed, and tail boom dented.

Had I been up high it would have been worse I'm sure. I still can't believe I neglected to inspect the pre-assembled tail. :oops:

[GGoodrum]

I just got a Mikado V-Bar system. They recently dropped the price on these a bit and I got a great deal on it so I pulled the trigger. Not sure what I'm going to put it on yet, either my Logo 10 or on a Logo 500 when I get one in April.

-- Gary

[MarkWebber]

Gary

Why wouldn't you just use your AP2000i? If you just wanted to spend money, I'd gladly have sold you another one :D

Must be the close proximity to all those electrons causing confusion...you know...that low nitro diet :wink:

[GGoodrum]

Actually, I had told Sean, at Aero-Model, that I would take one when they were first announced. When they finally came in, and I found out the price, even at my dealer cost, I told his people to hold off sending it to me. I told Sean that Ralf was pricing these things too high by twice, and he more or less agreed. I'm guessing Mikado hasn't moved all that many because just this week they had a fairly significant price drop. The retail price is now under $1000, but it is still too high, I think, even if it does include the 3rd axis tail gyro, and the airspeed sensor to control pitchups doing forward and backward flight.

In any case, I wanted to make sure I was at the "front-of-the-line" for the new Logo 500s and 600s, when they show up in April, and so I agreed to take delivery of the V-Bar, at a "special" price, and give it a whirl, so to speak. As I said, I'm not even sure what I will put it on yet. Maybe my Raptor that is setup for 3D. I'm also considering putting it on my Logo 10 Carbon, but I'm not even sure how to use it with the AP-2000i, which is not coming off. However, I'd like to get the extra 15%, or so, in efficiency improvements these things seem to be able to deliver, as that would add to the durations for my a123-based setup, so I'll probably try and make it work with the AP-2000i. I still think our ultimate solution is going to be a AP-2000i variant that uses Angleos' new gyro, and that combines inertial-based stabilization with the digital flybar functionality.

As for your neurological concerns, it is no coincidence that our own brain and nervous system use those same electrons. :D I think you've been standing a little too close to your Raptor's tail pipe... :D:D

You are my new project. :D Once you try it, you'll never go back, just ask DJ... ;)

-- Gary

[MarkWebber]

:lolol
As for your neurological concerns, it is no coincidence that our own brain and nervous system use those same electrons. I think you've been standing a little too close to your Raptor's tail pipe...

Ah, yes...but it is not electrons which start this process...it is carbon based fuel :wink:


You are my new project. Once you try it, you'll never go back, just ask DJ...

I agree...and once Greg let's me try out his converted Magnum, I'm sure I'll be hooked

[MarkWebber]

Reguarding the v-bar, I don't get the airspeed sensor. Unless they're not using HH gyros. I've noticed that pitchup is gone as soon as I've switched to HH.

I almost wish I had an electric right now. I'd love to convert it to find out how close to that 15% improvement ditching the flybar actually yields.

[oscillator]

Hey Gary - welcome to the flybar-less club. Interested to see how the Mikado V-bar compares to just using gyros and a mixer.

Mark - did you change your gains when you went to HH? I'll have to give it a try.

Thanks to FX Aero I was back in the air in less than 24 hours. Since I was rebuilding the tail I went ahead and installed the longer boom. Still using stock blades all around. Installed the carbon tail, hardened tail shaft, and thrust bearing tail hub. Probably won't make a bit of difference, but what the heck.

Just got back from 2 flights at the local park. I haven't made any head speed adjustments yet, but one flight was 11+ min, the other 12+ min, on 10s1p A123 Dewalt pack. Flight consisted of basic circuits, hovering, climb outs and hovers at 100-200 ft AGL, piros, etc.

Once again it was windy as all get out. I had to use almost full forward trim to hover at alt into the wind. The heli was quite stable even without the AP2000i turned on, but turning it on was of course better.

Despite all this great electronics, I could not piro without getting blown all over and it looking ugly. I guess this was largely due to the wind. At least that's my excuse.

I also noticed the piro rate was very slow - probably due to my head speed and a stretched boom with stock length tail blades. Not that I want fast piros on an AP ship...

The other surprise was noticing 18 glitches on the AP2000i after my 2nd flight. I'm guessing this was due to static off the new tail belt. Anyone know a fix for this? I saw one post on the Mikado forum that claimed lubing the belt led to belt rot and failure.

[dreslism]

Wow, sounds good Mark.

Runtimes sound good too!

About the static, many have been grounding the tailboom, and that seems to take care of it.

I am pretty sure it was Mark L. that said if he spooled up in the garage with the lights off, he could see the static sparks.

[MarkWebber]

did you change your gains when you went to HH? I'll have to give it a try

I'm at 14% on both sides. IR on the rate mode only, though. HH does a good job of keeping it where you last directed the heli.

[AZ ChopperCam]

Once you try it, you'll never go back, just ask DJ...


yup! I went from having about 7 nitro powered planes and 3 nitro helis to zero nitro helis and only 2 nitro planes left... all else have been converted or retired.

Electric from here on out.... forever!

which BTW.... I still have an OS50SXH with new TT muffler that I need to get rid of. First $70 gets it. :lol:

[oscillator]

Tried the HH mode on the roll and pitch gyros today. Wow! :glasses2: Talk about stable. It basically stays where you put it. Hovering is comparable to my blade CX - you can take you hands off the sticks for 5 seconds or more! I bet my 8 year old could fly this one! It will still drift off position, and the gyros won't turn the heli upright if you get sideways, so it doesn't eliminate the need for the IR sensor - but it sure is sweet to fly.

Once I got the feel of flying in HH I had a blast just doing stall turns, eights, and basic patterns. Looks like I may need a 2nd Logo 10 for a 3D ship. Not to mention I'm loving the 12 min flights on a single A123.

The only problem remaining is the A123's are too heavy for the battery tray on the Carbon Logo 10. I tried a quick fix with some string, but it really needs proper bracing. I've noticed that the battery tray flex can actually cause the heli to bob in pitch. At first I thought this the result of too much gyro gain, but it did not diminish with reduced gain, and I see no similar motion in roll, so I've concluded it is the battery movement.

Once I get the bracing solved it will be time to put the camera on and start seeing what this platform can do.

Oh, I re-routed some wires away from the tail and haven't seen any more glitches. The glitch counter on the AP2000i is a great feature - even for us DX7 users!

[MarkWebber]

HH is awesome, ain't it! :D Can't wait to get a better gyro on the cyclic. :wink:

[davethomaspilot]

Oscillator,

In one of your posts you mentioned just getting the Vbar parts. Are you using the Mikado Vbar mixer, or just AP2000i with the gyros? Were you referring to the flybarless head, and not the Vblade mixer?

Also, can you post a picture on how you mounted the gyros?

Thanks,

Dave Thomas

[oscillator]

Dave,

you are correct - My Tx is set up for no mixing, the Aileron and elevator signals come out of the RX and into separate gyros to correct for roll and pitch, and then into the AP2000i for eCCPM mixing. I am using the Mikado flybarless head parts, but not their electronics.

Gota run now, but I will try to posts some pics later showing the gyro mounting.

Cheers,

[GGoodrum]

Okay, I'm sitting here trying to figure out how to make the V-Bar and the AP-2000i work together. I've decided to go ahead and install this on my Logo 10 Carbon setup, but I can't figure out whether the V-Bar should go ahead of, or after the AP-2000i unit. Like the AP-2000i, the V-Bar expects basic non-CCPM inputs. The V-Bar can output in this mode as well, as can the AP-2000i, which means either one could go before or after the other one. So which should come first, the chicken or the egg? :)

-- Gary

[MarkWebber]

Gary

The Chicken...I mean the AP2000i :wink: Otherwise, the V-bar stability would want to fight the IR stabilization of the AP2000i. Obviously, use caution in this untested venture.

[GGoodrum]

Yes, of course, that makes perfect sense Use the AP-2000i to adjust the "commanded" stick movements, and the V-Bar to do the flybar stabilization.

Thanks Mark. :)

Life would be so MUCH better if Angelos would hurry up and get his gyro done so that he could do a new AP-2000i variant that can do inertial-based hover stabilization AND flybar elimination. :mrgreen:

-- Gary

[GGoodrum]

BTW, if you guys are using the gyros ahead of the AP-2000i, what will happen if you turn on the IR stabilization? Won't you have the same problem you just described?

[dreslism]

BTW, if you guys are using the gyros ahead of the AP-2000i, what will happen if you turn on the IR stabilization? Won't you have the same problem you just described?

You're right Gary, things would be much easier if Angelos would just give us a new black box that was not $1000.

You're making my head hurt thinking about this. :D

[MarkWebber]

Gary

Not in rate mode. I've flown it with the IR and it works just as well as you'd expect.

Scott

Take a couple asprin and I'll show you at Toledo :D

[oscillator]

Gary,

I've tried the IR in HH mode as well, and it works as expected there too. Only "problem" is the heli is so dang stable in HH mode it is hard to notice the IR is doing anything - but it is.

Put the heli in HH mode in a stable hover and it basically sits there. Give it some cyclic and the rotor tilts, then stays tilted until you tell it otherwise. With the IR, as you would expect, the AP2000i will "tilt" the rotor back level.

Once you get the V-bar figured out we will have to hook up and do some comparison flying. I'm quite curious what advantages the V-bar delivers over gyros. And yes, we need Angelos to deliver an inertial module that incorporates all 3 gyros, simplifies the wiring, and brings the cost down. Even the 3D guys would want an AP2000i then. Hmmmm...scratch that. These things are hard enough to get as it is.

[GGoodrum]

The V-Bar is basically just a computer widget, like the AP-2000i and a 3-gyro sensor. The latter is about the size of a 401 or a 240, and it contains all three gyros. There is also an airspeed sensor that senses forward and backward airspeed. The computer uses this to control pitching up during basic forward and backward flight. For 3D-style flight, the airspeed sensor does nothing and can be left off. So, this is really just an AP-2000i with inertial sensors and a different software load.

It comes with a PC application that you can use to program pretty much everything. Right out of the box it is setup to basically just mimic the stabilization that a flybar would provide mechanically for a 500-600 - bladed model. Basically it would be just like what you guys are doing with your gain-tweaked 401s in rate mode. The difference is that with the 401s you have two computers, each co-resident with each sensor. There is also a pre-programmed advanced/expert setup which I gather is what the likes of Andy Rummer, et all, are using to do their insane 3D routines.

Like I said, you can adjust just about every aspect of controlled flight with this program, so I'm sure there's a way to do a Heading Hold sort of function for the cyclic movements. Oh, and it has the tail gyro function embedded as well and supposedly you can have as much control as a 611 and/or a CSM720. Finally, you can have two completely different setups programmed into the widget and select between them using an aux channel on the radio.

What we really have here are two inter-related stabilization "problems". The first is getting rid of the flybar, and digitally providing the same sort of basic stabilization that the flybar provides mechanically. The second is to try and help keep the helicopter "parked" in one spot, like the Carvec system can do. Using 401s to do the flybar replacement function just requires the rate mode to be used. The AP-2000i is then just used to do the eCCPM conversion. The V-Bar system does pretty much exactly the same thing, from a purely functional point-of-view. It just splits off the gyro rate function from the sensor and does it in the same widget that does the eCCPM conversion. The AP-2000i also has the IR sensor, and the sensing software that attemps to keep the "wings level", so-to-speak. We've been waiting for inertial sensors for the AP-2000i to replace the IR unit to sense attitude changes. Wouldn' that just end up being the same sort of Heading Hold-type of functionality, applied in each axis? I mean, what more will an inertially stabilized AP-2000i variant do for us?

Before my head explodes ( :bomb: ), I have one more question. if all you did was replace the IR unit with inertial/gyro sensors, would/could the Cal function work the same way? In terms of the 401 solution, with both of them in the HH mode, what is needed, I think, is a "Cal" function that would autmatically adjust the gain maybe, to keep the heli in one spot?

Okay, that's it... There's gooy grey matter everywhere! :shock:

-- Gary

[oscillator]

Gary,

I'll let Angelos tackle that one. Seems like you would need some way of "storing" where level was so you could move the heli back there once the user let go of the sticks. A HH gyro just stays where it is once you let go of the sticks.

But hey, time for some pictures. First up is the RX and the traditional tail gyro..
http://www.helifreak.com/album_mod/upload/48d266f4988ee786ff08fd2e593b8763.jpg

Next we have the elevator or pitch gyro, along with the AP2000i and the BEC:
http://www.helifreak.com/album_mod/upload/2cec91199cdc3b534c9ffafb2fcc8815.jpg

Notice that head kids. No flybars here, no sir. :mrgreen:

And finally here is the Aileron or roll gyro:
http://www.helifreak.com/album_mod/upload/d9ba701ba4140aff8f7cd2c61f19fc11.jpg

The elevator (pitch) gyro is a concern. Strapping down a gyro with a tie wrap is a bad idea as vibrations can confuse the gyro. But having the foam tape fail in flight would most likely be unrecoverable. Therefore checking the integrity of the adhesive mount is a critical preflight item.

[GGoodrum]

Looks great. :) Is there much of a difference between using a 240, vs a 401?

-- Gary