Anyone using a BD3SX?

[helihammer]

Are any of you Pantera nuts using a Bavarian Demon 3SX FBL controller? I have had one installed for a while now and can't seem to get rid of an elevator lurching.

I've tried using the default settings for this size machine recommended in the BD forum but I still can't get rid of the behavior.

The aileron movements are fine, but the slightest touch of forward elevator causes lots of forward movement. I've played with the gain and other parameters but I just can't seem to get it right.

This frustration was at one point enough to make me say screw it and put the flybar back on, (which flew beautifully as always) but I spent enough money converting over to FBL and on the controller so I might as well try to make it work. I have tried both the RNFBL and the later type conversion that uses metal arms and the transfer collar from the Quattro head design and both of these have the same behavior so it's gotta be the FBL controller.

Also, if anyone has had success with another controller on a Pantera, I'm all ears!

[jiminator]

Have you read thru this post? I don't have a Pantera yet but am running a Hc3sx on another heli.

https://www.helifreak.com/showthread...levator+bounce

[helihammer]

I had read through that post awhile back, yes.

This "bounce" however is nothing like that.

See this post:

https://www.helifreak.com/showthread.php?t=735179

As you know, the gain settings are interactive with the overall head gain.

Since I needed more elevator gain than I could obtain with a head gain of 55, I turned the head gain up to 70 and then turned the aileron gain down a bit to keep it the same as it was with a 55 head gain.

With the head gain at 70 and an elevator gain of 12, the sharp rocking motion is greatly reduced, but still present. The tail also bounces a bit when a sharp elevator command is given. Giving sharp aileron commands causes the heli to shake side to side a bit, so I may need to lower that even further.

I think I can fix it by raising the elevator gain and playing with the elevator filter.

Also, I think the overall gain may be too high because the machine tends to rock around a bit when given lots of collective after dropping it from some height (sort of like a pitch pump).

It's just frustrating because there's so many options to play with. With the flybar, it flew great and I just accepted it for what it was because I couldn't change it.

I'll try to take a video soon to show you what I mean.

[helihammer]

I tried another flight just now. I loaded the default settings and set the TX up so I could vary the head gain on a 3 position switch with values of 55, 65, and 75.

The heli felt fine at each gain setting, but there was noticeable bouncing at 75, so I think somewhere around 60 would work OK.

The highest of 75 reduced the rocking motion somewhat, but was obviously too high as there was bounce present in the aileron axis too.

I guess what I'm trying to explain is that the FBL controller just feels different than the flybar and that the elevator movement is a little more aggressive than I would expect. Maybe trying to tune it out is futile because that's just that way it is?

It's not all that bad if the elevator stick is moved forward slowly, so maybe I should just learn to live with it.

[jbeech]

As yes, the new hobby of dealing with an FBL gyro. You've been fooling with this a long time. I wish I had a 3SX because I'd loan it to you to see if the problem is the 3SX (obviously the problem but it pays to be certain). Anyone?

[helihammer]

Well one thing I could always do is revert back to the flybar and use the 3SX as a tail gyro only and for rescue if needed. I had been doing that and it worked fine, I just wanted to use the thing to its full potential. That, and the FBL conversion looked great! I'll fool around with it some more but if I can't get it, it will be time to take the flybar out of storage!

[jiminator]

After trying three different fbl units, Hc3sx, Ikon2 and Vbar, I'd have to say Vbar is my favorite. Pretty much been set and forget with few exceptions. As John said tuning a fbl is a hobby in and of itself. Do wish I had a spare unit to send you but the "spare 3sx" box is empty at the moment. I'd say as long as you're on the tuning path keep with it until every option is exhausted. If the ship is still not responding as you expect it too then try something else. With a fbl you shouldn't have to live with weird tendencies that don't exist on flybar equipped models. A good fbl unit will seem to iron out all the little corrections you as a pilot will be making to keep your flybar heli flying thru manuvers smoothly. It will lessen your workload. Hope you're able to dial it in

[helihammer]

I tried going back to the default settings (posted in a sticky at the BD forum) and added 20% expo in the radio. With a head gain of 60, the sharp elevator rocking upon small stick input is mostly gone. I'll try some more stuff to get it ironed out. At my skill level, I don't know what an FBL "should" feel like, I just know that it wasn't doing what I wanted.

I did, however, fly a friend's Trex-450 with the Align 3GX on it and I didn't like the feel of that thing at all. The tail was so squirrely and couldn't be dialed in.

[helihammer]

Well, I did it. I got the flybar back out last nite and looked it over. With the addition of two linkage rods I had to make up, it took about 10 minutes to put it back on. John has said it in the past, the flybar is bulletproof.

"Q. Why does this model have a flybar?
A. It's because the flybar allows you a more simple and economical entry into flying. Models with a flybar perform very, very well without the complexity of dealing with flybarless gyros, which can get very difficult to fine tune (or even turn into a separate hobby). We know because we see a lot of pilots who begin taking a computer with them to the flying field and are constantly fiddling with parameters. Us? We prefer to fly and a flybar makes it easy. This despite have significantly more parts (by the way, this is the one exception to my rule about fewer parts being better)."

From now on and for the foreseeable future, I am going to use the flybar and just use the 3SX for rescue and self level if I need it.

John, if I start talking about an FBL setup again soon, please don't hesitate to shoot me in the foot! I'll return to FBL once I have flown it till the flybar flies off!

[Yooper42]

I 2nd your opinion....my p6 has a FB still. No real plans to change anytime soon. I have a Vbar in the box that I may install fir next year but yes, i agree fbl controllers are another hobby in themselves. I fly my 60cc Bergen gasser with no controller, but that being a single servo setup I think makes it possible compared to ccpm.

[jiminator]

Maybe the demon inside the BD3sx simply didn't want to cooperate