Mikrokopter ACC Calibration & what do you level

[Macsgrafs]

Hi everyone,

I was just sat here thinking about my last octo flight & was wondering if my slight drift could be caused by the ACC calibration being off????
I hope someone can answer this one for me

When you do the acc calibration do you:-

A)Have your MR aircraft completely level?
B)Have your FC board level & dont worry too much about the MR aicraft being level?

If its the FC that needs to be 100% levell as I suspect, do you have it plugged into a notebook/computer & level it so that it looks at 0,0,0 in MK tools?

Ross

 

[alexoki]

From my understanding it is the motor/prop plane that has to be completely level so the position of the FC during ACC calibration does not really matter as long as your props are all level with each other.

 

[RTRyder]

Hi everyone,

I was just sat here thinking about my last octo flight & was wondering if my slight drift could be caused by the ACC calibration being off????
I hope someone can answer this one for me

When you do the acc calibration do you:-

A)Have your MR aircraft completely level?
B)Have your FC board level & dont worry too much about the MR aicraft being level?

If its the FC that needs to be 100% levell as I suspect, do you have it plugged into a notebook/computer & level it so that it looks at 0,0,0 in MK tools?

Ross

In a perfect world the F/C would be parallel to the frame so it wouldn't matter which way you do it, the reality is that it doesn't always work out that way. I try to get the F/C as close to level in regards to the frame as possible, usually just shimming the standoffs a bit is all it takes and I have a small piece of bare G10 I use in place of the F/C to measure for level. After that I get the frame perfectly leveled on the bench and then do the calibration and in theory it should hover nice and level. If after all that it's still off a bit then I start looking at the motors to see if one or more are off vertical, usually I'll set all of them to as close to straight up as I can and if there are yaw issues then maybe tilt them a degree or two to help with the yaw authority.

If you level to the F/C and it's not square to the frame the multi will drift as the F/C gets itself to level the frame will be tilted a bit. If that's he case it will always want to drift in the same direction. If I see that on one of my non APV craft sometimes I get lazy and just use a bit of trim to fix it until the next time I have reason to be doing maintenance on it, the APV stuff gets fixed correctly.

Ken

 

[Macsgrafs]

Thanks Alex & Ken.

I'm quite sure the FC board is level, so I'll level the frame correctly & re-calibrate again to see if I can stop the drift, which as you said Ken seems to be one way only

Regards
Ross

 

[Muunk]

Can someone tell how to level the wookong m?

 

[RTRyder]

Can someone tell how to level the wookong m?

You don't, make sure the IMU is level on the frame and do a compass calibration. That's all you can do with the WKM, it's not like the MK where you have to calibrate the accelerometers with frame perfectly level.

Ken

 

[Bartman]

Ross,
Before I add the Navi and GPS I mount a small square plywood plate on the studs that hold the FC in place and keep it tightly on the studs with nuts. On the plate I place a bubble level and this is about as close as I think I can get the FC secure and in the same plane as the top of my top frame plate. I use business or playing cards under the gear to center the bubble level and then I do the calibration (left stick up and to the right). I don't make any attempt to figure out if the arms and frame plates are all perfectly level or not, I just assume if everything is fastened securely then I'll have it all as close as it's going to get without a government budget supporting me.
After I do the thing with the bubble level I go for a flight or two and watch to see if there is any drift. My latest build flew the best ever so I got lucky. When I do have any drift I use small squares (maybe 1/4" square with a 3mm hole punched in the middle) of playing cards to shim the FC. If the kopter is drifting to its right, I raise the left side of the FC by a shim or two. If I put two on one side I also put one in the middle, front and back to keep the FC from being flexed by my shims. After a few flights I end up with a kopter that flies level and with zero drift. This is without any use of the radio trims, subtrims, etc.
Have a go at it, I think it'll work great for you.
Bart

 

[Macsgrafs]

Now thats a great idea Bart, so if I take all the electronic boards off including the FC board, then replace the FC board with a sheet of plywood & place the bubble level on that. Once level, rempve wood & replace with FC board...correct so far? Sorry I'm a bit...errrr....slowwwwwwwwwwwww tonight

Ross

 

[Bartman]

take off the GPS and then the Navi but leave the plastic studs that the Navi was sitting on. Cut a square from light plywood (1/8" +/-) and drill to match the FC hole spacing. Sit in where the Navi was and secure it with nuts. put the bubble on that and it will get the FC as close as possible.
After you do the calibration, fly it and note which way it wants to go. shim the FC in the direction it's trying to go......if it's trying to drift right it's because it thinks it needs to lift the left side to be level.....to fix it, remove the FC and stick two shims under the left side, one in front, one in back and reattach the FC. fly it again and see if it's better. it may take a few tries to really get it perfect.
good luck,
bart

 

[Macsgrafs]

I'm with you now Bart, I think that should work nicely for me. Going to give that a try the minute we get soem half decent weather
Thanks for your tip by the way, that seems a quick & easy route...wicked

Ross

 

[Bartman]

Good luck with it Ross. Just remember to remove the shims if you should decide to do a new calibration.....IOW, don't recalibrate it with the shims in there as the previous calibration is what is being corrected with the shims.
Bart

 

[Macsgrafs]

I got it now I think Bart, I'm sure I could just shim it as it stands to get it right...I really must check the CofG as well while I'm at it

Ross