Trex 450 K Bar/v Bar Setup

Discussion in 'Align' started by beenflying, Jun 8, 2014.

By beenflying on Jun 8, 2014 at 10:57 AM
  1. beenflying

    beenflying Member

    Joined:
    May 23, 2014
    Messages:
    85
    Likes Received:
    29
    I've just put a yellow K Bar on an Align Trex 450 Sport that I've had for some time. It's been using a ZYX v4, which flew pretty well, but now I'm moving most of my fleet over to the K Bar. The tail servo is a KST DS115MG micro servo, that is quite fast at 6 volts (which I'm using).

    The yellow K Bar uses a digital 3 axis MEMS and a second MPU to emulate the older analog sensors, one of which is now end of life. So the gyro is a bit of an unknown, and this is the first time I've tried it on a 450.

    The heli flew well on the default settings, but the tail wasn't as good as it used to be. Changing the gain just took it from wag to mushy, but it still felt odd, with strange kicks and the odd flutter, especially with puffs of wind.

    The Accel setting had no effect from 55 to 75 and the P gain didn't help. I tried the I gain from 50 to 90, and that didn't help, but when I set it to 40 it was better. I then had to increase the precomp (currently 44, but I'll play with that some more).

    William has offered to show some settings for his 450's that look to fly very well, especially with his excellent flying skills. I know he spends quite a bit of time getting his helis right and he has a lot of experience with the V Bar. This K Bar may however require different settings, due to the different sensor setup.

    If anyone has a good working setup for a 450 then please share it here.

    I've attached my current tail settings, but I'll play some more to see what's best.

    DSC02978.JPG

    450 Sport Tail 1.jpg
     
    Last edited: Jun 11, 2014

Comments

Discussion in 'Align' started by beenflying, Jun 8, 2014.

    1. beenflying

      beenflying Member

      Joined:
      May 23, 2014
      Messages:
      85
      Likes Received:
      29
      This seems pretty good:

      450 Sport Tail 2.jpg

      I'm surprised the I gain needs to be so low, but it sits nicely side on to the wind and holds well. The overall gain is able to go quite high now for a 450. It has no wag at 76%.
       
    2. beenflying

      beenflying Member

      Joined:
      May 23, 2014
      Messages:
      85
      Likes Received:
      29
      Here are the rest of my settings, so far:

      450 Sport Both 1.jpg
       
    3. feral

      feral Well-Known Member

      Joined:
      Mar 14, 2014
      Messages:
      2,299
      Likes Received:
      1,461
      Speak to @jockstrap he is the undisputed clone king of the world
       
    4. William

      William Active Member

      Joined:
      May 14, 2014
      Messages:
      278
      Likes Received:
      241
      Sorry guys fell asleep before doing heli projects last nighto_O

      Tail settings L.JPG
       
    5. beenflying

      beenflying Member

      Joined:
      May 23, 2014
      Messages:
      85
      Likes Received:
      29
      Interesting. Those are the default settings. Even my 450 Pro stretched, with the GV8000 (vbar), didn't like those settings.

      Do all of your 450's with vbar use those settings?

      Thanks for posting them.
       
    6. William

      William Active Member

      Joined:
      May 14, 2014
      Messages:
      278
      Likes Received:
      241
      I can check, I know I had to tinker with the X3 a little on the stop gains... But default has worked good on most... I was wondering why you took out all the Expo?
       
    7. beenflying

      beenflying Member

      Joined:
      May 23, 2014
      Messages:
      85
      Likes Received:
      29
      Thanks. I prefer to set the expo in the TX. That way the expo is consistent, when I use different flybarless units.
       
    8. beenflying

      beenflying Member

      Joined:
      May 23, 2014
      Messages:
      85
      Likes Received:
      29
      William, what mounting foam do you use?
       
    9. William

      William Active Member

      Joined:
      May 14, 2014
      Messages:
      278
      Likes Received:
      241
      Last edited: Jun 9, 2014
    10. beenflying

      beenflying Member

      Joined:
      May 23, 2014
      Messages:
      85
      Likes Received:
      29
      I'm starting to think the foam is my problem. Rodo1268, on rcg, says he's experienced the same problem on his 450's (he calls it "tail turrets syndrome" :D ). He uses the Horizon BeastX foam to overcome the problem.
       
      Last edited: Jun 9, 2014
    11. The Dude

      The Dude Well-Known Member

      Joined:
      Mar 4, 2014
      Messages:
      1,070
      Likes Received:
      650
      + 1 on the foam...
       
    12. jockstrap

      jockstrap Active Member

      Joined:
      Apr 3, 2014
      Messages:
      347
      Likes Received:
      212
      @feral - Beenflying knows way more than me dude - I think he's more addicted to testing new stuff than me and is quite a well known tester on rcgroups :)

      @ Beenflying - Will be interesting to see what you come up with re the "Yellow" kbar.
      Seeing they epoxied the gyro chips and as you say we don't know what they are - so they could be inferior to the blue kbar - which performs well.

      Infact - I was getting tail blowouts on my 450 with heavy rainbows with beastx and simply put a blue kbar on - no other changes - default settings and no more tail blowouts..
      So I know the blue kbar performs really well.

      The yellow, I've only tried so far on my Gaui X4 and have tail hold issues on default settings. However the heli is new to me and I am running larger blades and maybe too much pitch. I lowered pitch today and seems better but still had tail artefacts.

      So i'm beginning to think the gyro chips in the yellow may be inferior and hence why they are cheaper and epoxied over...
      What I need to do is to swap one of my blue kbars from one of my 450's to the X4 and see how it goes... but i'm lazy... lol

      Targethobby have the blue ones really cheap atm and that's where I got my others from - so ordered 2 more :)... when they come I will try one on the X4 and see what the difference is between the blue and yellow on default settings... I'm suspecting there WILL be a difference.. but hope not as I've got 2 yellow ones already - lol

      The interesting thing is I have a GauiNX4 (which is basically the nitro version of the X4) running a fubar - it has even larger 473mm blades than my X4 (465mm) and both run stock tail blades - the NX4 has no tail issues at all on stock settings - the X4 with yellow kbar does..
       
      Last edited: Jun 9, 2014
    13. beenflying

      beenflying Member

      Joined:
      May 23, 2014
      Messages:
      85
      Likes Received:
      29
      The yellow K Bar uses a very high quality 3 axis digital MEMS. It's much better than the old single and dual analog MEMS. That's why in the ginglish they say it inherited the advantages of silver, and why it's called the gold K Bar (because it's better due to the side mounting feature). A second MPU looks at the button, stores the mounting setting, and sets up and translates the digital MEMS, so the main MPU sees what appears to be 3 single MEMS. Temperature compensation is also far superior to the old MEMS.

      The one in my 550E flies incredibly well, and that one is mounted on the side of the frame, with thin tape. I'm confident the foam will sort out the issue on the 450. The cyclic is already super smooth, and stable, even in the high winds we had in the weekend. I'll let you know how I get on.
       
    14. beenflying

      beenflying Member

      Joined:
      May 23, 2014
      Messages:
      85
      Likes Received:
      29
      What about head speed? How does that compare?
       
    15. jockstrap

      jockstrap Active Member

      Joined:
      Apr 3, 2014
      Messages:
      347
      Likes Received:
      212
      Well - My NX4 cranks but the X4 is also high on idle-2 maybe not as high.. but not by much..
      Next test i'll have to crank the X4 a little if I can and compare..

      Unfortunately don't have a tach to measure them both..
       
    16. jockstrap

      jockstrap Active Member

      Joined:
      Apr 3, 2014
      Messages:
      347
      Likes Received:
      212
      Oh that's interesting... and good news :)

      My cyclic is also very good - just the tail issues... which could easily be my setup..
       
    17. beenflying

      beenflying Member

      Joined:
      May 23, 2014
      Messages:
      85
      Likes Received:
      29
      I've heard that the tail setting P = 75 and I = 75, works well, with the right tail servo and arm length. I'm using this on my older 550E. Do you have the same tail servo in both helis?
       
    18. jockstrap

      jockstrap Active Member

      Joined:
      Apr 3, 2014
      Messages:
      347
      Likes Received:
      212
      I'm fairly sure both tail servos are the same as they are both the gaui 518's I think...
      Interesting comment thou - when I get a chance (at work atm) i'll check the arm length on both - as the boom and tailboxes are also identical.

      I'll double check what settings are in the fubar for nx4 tail and see if they are the same in the X4 - basically, tail backwards the two helis should be identical.
       
    19. beenflying

      beenflying Member

      Joined:
      May 23, 2014
      Messages:
      85
      Likes Received:
      29
      Good news on the 450 tail front. After changing to a softer foam, I'm now able to run the default tail settings of P=80 and I=60. I have a slight stop bounce, so I'll try playing with the accel/stop settings and I'll also try a strap, like @William uses.
       

Share This Page

test

    About Us

    Just like you, Heligods staff are regular everyday fliers. Join our forum and participate in what will become the worlds greatest rc helicopter forum..

    Credits:

    A big thank you to the following people who helped us put together this site:

    Pope Francis

    Deli Lama

    George Bush

    Gene Simmons (aka Crash)