ELEV-8 unstable flight HELP!!

Samson

Hello all, this is my first post to the forum.

I am having issues with the stability of my ELEV-8. When the quad lifts of the ground it starts jerking back and forth in the air and then veers toward the ground. I am using 25a castles creations talon speed controllers and gemfan 1000kv motors. My radio is a spektrum Dx6i. I was thinking it could be an issue with my pid values but I am unsure of how to set them on my radio. I would greatly appreciate any ideas on how I could fix this problem.

Thanks so much!
Samson

Ken Gracey

Hey Samson,

Is it a Parallax original kit or a version you made from our files? I'm not familiar with the Castle Creations speed controllers, but you should check the Hoverfly ESC Compatibility spreadsheet on their website to see that this ESC is a good match.

Go to Learn.parallax.com and take a look at the radio setup for DX6. We detail it down to every possible step you might need....and you only have one radio setting - the CH5 which is gain, starting at 25%.

Ken Gracey

Kyle M.

As Ken mentioned, instructions on configuring the transmitter can be found in Step 22 of the ELEV-8 v2 Assembly Guide. While in general the ELEV-8 v2 instruction manual should not be used with other versions, this particular step is the same for the first and second versions of the ELEV-8, so you are good to use it!

Besides an incorrectly set-up transmitter (which the above should fix), other possible sources of the problem include (roughly in order of likelihood):

• unbalanced quad. the center of gravity of the quad should be directly under the center. you can test this by using your index fingers to lift opposing booms (place straightened fingers underneath the boom but inside of/above the landing gear). Carefully lift the quad up this way. If it very quickly rotates one way or another, then it's out of balance and you need to shift components around until it either doesn't rotate at all or does so slowly.
• not allowing gyroscope to calibrate. After you plug in the battery, the quadcopter needs to remain absolutely still and motionless until the light on the hoveflyOPEN is flashing green
• Improperly configured flight controller. make sure you've properly configured your flight controller (see instruction manual for details)
• speed controller setting issues (I too am not familiar with those speed controllers, so I won't be much help there)
• wiring If you have motors/ESCs mixed up. while this usually will cause the quad to crash the instant it begins to lift off the ground, but there are actually a few cases where that may not occur
• defective electronic speed controller or flight controller.

Patrick Coleman

Hello,

I have a great deal of experience with multirotors and Castle Creations ESCs.

First, the talon (im checking), but i dont think it can be used for multirotor purposes. the Thunderbird series for instance cant, its a prop plane only ESC.

Second, if a primitive version of the firmware is loaded, and its capable of being changed, then it may present itself as uncontrollable wobbles, many blame these oscillations on PID settings, but the Castle ESC's have very sophisticated math to control airplane prop motors. That makes them very good at this task, but unfit for the feedback loop a flight controller expects.

Third, can you get a Castle link? i can walk you through the changes.

You can PM me here on the RCgroups forum too : http://www.rcgroups.com/forums/member.php?u=437848 (my page)

( I confess this knowledge, as I had a Castle ICE 50 powered Bi-copter, it showed the same signs until firmware 4.01, then that solved the problem entirely. I felt like a dope. ) There are other possibilities, but lets start here.


Patrick Coleman,
EE Student, CSU Chico.