Blade 400 Flybarless Conversion with CopterX CX-3X1000 -- Success!

[jabu32]

hows the FBL working? still waiting for mine to arrive.

[Harbormaster]

Originally Posted by jabu32

hows the FBL working? still waiting for mine to arrive.

It's working well.

Did you see the short inverted segment in the video in post 14? (The embarrasingly bobbley flips got better as I got used to the setup.)

I just edited post 14 to say that I had the "I gain" (the longer term stability setting in the Advanced menu) set 1/3 lower than I thought it was that day. I was expecting sport flying stability (F3C setting) when the "I gain" was at the same level as used for "Hard 3D" (i.e., less long-term stability added) so no wonder it felt a little wobbly--that's what I had set it for.

I tried another test flight last night after work, but my tail rotor drive gear failed, so no joy. (That gear was probably the last original part in the whole heli.) If the LHS has a replacement I might be able to get out this weekend. I hope so.

[Harbormaster]

Ten flights today! She's pretty much all done 'cept for some fussing with settings just to see what they do.

• It flies just fine with the stock F3C settings at 2500 and 2700 RPM with flips, rolls, and inverted. (No loops or really fast forward flight.)
• Higher headspeed makes it more subject to oscillation with higher gains (see below).
• I actually reduced the Roll and Pitch agility from 35 to 30, which made it noticeably less sensitive to stick input (less twitchy for sport flying, but the flip radius did increase slightly).
• The heli flies fine but still doesn't feel quite as locked in as my VBar 450 (which has had a lot more tweaking).

Playing with the Roll and Pitch P gains:
No oscillations at 2500 RPM with gains of 80 to 100.
At 2700 RPM:
P gain 85 (5 over stock) I had one very minor, transient oscillation.
P gain 90 I had one stronger, more sustained oscillation.
P gain 100 developed a sustained oscillation when flying backward. The oscillation persisted even when I brought the heli into a hover. The heli still flew and was controllable, but this was the outer limit of controllable.
Conclusion: The stock setting of 80 is probably just about perfect for this bird (unless maybe some antivibration steps were taken).

So that's about it, I think. I had a nice time flying my FBL 400 on a sunny spring Sunday.

[Daddy]

Ok, thinking of doing this... Can I ask why the Copterx head 450ba-01-50 wasn't considered?

[Harbormaster]

Originally Posted by Daddy

Ok, thinking of doing this... Can I ask why the Copterx head 450ba-01-50 wasn't considered?

The one I used was a known, proven performer. Just a few swipes with a file and it fits right on the existing B400 main shaft. This is not to say that other heads won't work. The most important thing to check first is that the shaft diameter and hole size match.

BTW, I flew the B400 today in a light wind. It was flying fine.

[Luvmyhelis]

Outstanding work!

[berserkk]

halfway through this conversion....im waiting for my balls to arrive....,
did you require servo extension?

[Harbormaster]

My forward servo lead just BARELY makes back to the unit. I'll probably solder on a little more wire someday do I can route it better, but it's OK for now.

I hope your balls arrive soon.

[berserkk]

[ame]http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=320720442856&ssPageNam e=ADME:L:OC:AU:3160[/ame]

cool, i'm ordering this servo extension lead, its only like $2, kinda looks like it fits....

[Harbormaster]

That should be plenty long enough.

[LawnDartHeli]

Ive got all the stuff coming to do the conversion. But herein lies the problem...I have my 400 which already has good servos and whatnot, and I have a 450 clone with most parts swapped to Align&Tarot..It has so-so servos on it, but its full alloy with a much better tail set-up. Both are still barred at the moment, both have the same Kv motor..but which do I convert??

I love my 400, as its my first "big" heli. But my common sense is telling me the clone would be the better investment in the long haul.

What do you guys think?

[Harbormaster]

I'd say combine all of the best parts into one super Frankenstein heli.

[LawnDartHeli]

Or just go fbl on both?

I may do the clone first, and then apply what I learn to the 400..dunno.

[Harbormaster]

Originally Posted by LawnDartHeli

Or just go fbl on both?

That's what I ended up doing to my little fleet, one by one. Once you go FBL, you never go back.

[LawnDartHeli]

Im talking with Helihaven about building me a solid tail unit for my stock 12mm boom. Thats the only thing holding me back on the 400.

[LawnDartHeli]

I put some HK mg929ds's on the clone and moved forward with the fbl build. Did the setup this morning (Side note: It would have been nice if the Cx3x1000 would have came with paper instructions, as would the programming cable...had to search for the usb driver software to even use it) my head is still hurting from all the changes I had to make. I gave it a few brief hovers earlier, had the wobbles a few times but would smooth out. Still getting the tail sorted out. I'll have it out in the field tomorrow and hopefully get it lined out. Ive copied InFocus's setttings to try.

Gonna be good times ahead!

[Harbormaster]

Congratulations on getting it into the air!

(It should be stable and flyable right from the start with the default settings. I'd start with F3C, not hard 3D. )

[LawnDartHeli]

Yup, gonna load those setting first thing. Could you point me at the PID (or should I say either P, I, or D?) gains that I would need to raise/lower if it..
Drifts fore or aft..
Drift left or right..
Tail drift/wag..

Some insight on where to start would be very appreciated

[Harbormaster]

If your experience is like most people's, it's plug and play: you set it up with the stock beginner or F3C settings to get started and it flies. You can tweak the various advanced settings, but it shouldn't be necessary to do so. (I fussed with a lot of mine and came to the conclusion that I didn't need to.) If the bird won't fly right with stock settings (especially just in a hover), check your mechanical setup (especially vibration levels, gyro mounting, servo setups).

[LawnDartHeli]

I loaded the F3C settings and it still had the jitters, then I tweaked those settings with InFocus's. It smoothed out for the most part except for a slight elevator bounce..kept tweaking..it would shake every now and then. A friend of mine suggested trying his 450X blades, wow what a difference..solved the wobbles. Then it was off to the tail, it would drift..I changed settings, hovered (repeated about 10 times), adjusted mechanics on the tail..nothin' worked. Finally just gave in and added about 20clicks of L-sub trim...solid as a rock. Once that was handled I had to back the pitch way off, Id stab the collective and blow-out city. That was all me though, just had too much pitch travel. Once that was all done it would hover hands off even in the wind.
Guess Ill pick up some stock 450X blades tomorrow, I put the EXI blades back on to test my theory..wobbled its @ss off.