130-X Calibration and Fault Finding Manual

[cjcj1949]

I'm just putting a link to this. Most people know about it, but there is a bit about using subtrim if your gyros are creeping.

http://www.horizonhobby.com/pdf/BLH3...l_Addendum.pdf

[fred kaz]

Thanks for that link.

[kylelnsn]

Thank you! Saved for future reference!

[cjcj1949]

It can be difficult finding these things. I've had the 130-X a few months now and only just had a problem with vibration, although it's always had the high collective vibe problem. There's lots of good info in the 130-X thread but very scattered. There's a better description of how to change the sensitivity of each gyro, but it's buried. The 130-X is a good heli but it would be nice if a mechanical engineer could look at the vibration problem and get to the bottom of it. I'm electronic/software and I know a bit about second order systems, resonance and damping, but someone who deals with it a lot should be able to do a swept resonance test and find out what is going on.

A bit of software and a computer with a speaker should be able to do the job.

[whittm]

Thanks very much for this! A quick question, one of the checks is for servo drift, and the fix is sub trimming, never really thought about the drift my 130x has, especially when pirouetting, but as soon as you rotate it drifts badly, is this normal, or something to do with the problem described in the manual here? I have heared that the as3x has no piro compensation, but is this normal?

[cjcj1949]

It's not servo drift, but gyro drift. The gyro on each channel needs to pick a signal from the tx that corresponds to no rotation. On a good heading hold gyro this is picked up during the initialisation phase at switch on. It seems that the AS3X doesn't do this, or perhaps it works on a band and this band can drift off. Adjusting the subtrim would get the neutral back in the band. If this doesn't make sense I can explain more.

I don't know what piro compensation does on a proper flybarless controller as I don't have one. The 130-X does turn quite nicely and does what i expect it to do. When you hover a heli it leans to one side, normally the right to counter the tail thrust, which itself is there to counter main rotor torque. When a heli turns the main rotor will stay spinning in the same plane, that means that if you turn it through 180 degrees it will be still be tilted to the right, looking at it, but the heli will need to be tilted left, so it will move off to the right of the pilot until he/she corrects it. The heli is doing the right thing. Piro correction may sort this out, but if it does, it is going beyond replacing the flybar and should not be allowed in an A test, unless the BMFA change their minds, not that they have got that far yet. Piro correction may well be something else to do with a level of skill that is currently and probably permanently at my age beyond me.

[stephen. guest]

excellent link many thanks

[twister440]

Thanks for the link!!

[patmacca]

Very helpful thanks

[tomatwalden]

130-X Calibration and Fault Finding Manual

Thanks very much for this! A quick question, one of the checks is for servo drift, and the fix is sub trimming, never really thought about the drift my 130x has, especially when pirouetting, but as soon as you rotate it drifts badly, is this normal, or something to do with the problem described in the manual here? I have heared that the as3x has no piro compensation, but is this normal?

Yes, it's normal for a heli without piro compensation. Old flybar helis were the same. You need to control the drift with cyclic controls around the pirouette.

Piro compensation does this for you. Say for example you're in a hover and because of the wind, you're actually leaning right slightly on the cyclic to hold it steady on the spot. As you spin, piro compensation makes the constant changes to the cyclic needed to hold the heli on that spot. Without it, the swash would remain leaning in one direction relative to the body of the heli, and at one point (180 degrees) would actually be leaning WITH the wind!

That's why piros on flybar helis are difficult, and piros on FBL (with piro compensation) are much easier.

[cjcj1949]

Sounds like there's another word for piro compensation then. The 130-X seems easier to turn than a 450 flybar, the msr-x seems harder. Thanks Tom.

[tomatwalden]

Sounds like there's another word for piro compensation then. The 130-X seems easier to turn than a 450 flybar, the msr-x seems harder. Thanks Tom.

The mSRX has the rudder-swash bug in the AS3X which probably complicates things ...

[whittm]

Right guys, just want to correct myself! Very strange this, but, my +10 on the gyro gain is way out in normal flight! When hovering in my living room, there was no movement, but in the field tonight, I had big tail wag! I reset the gain to zero, and wala, no tail wag. On youtube one guy suggests -2 I'm going to try this next time I fly. I think while hovering, +10 was perfect, there was no tail wag, but in flight it was totally different.

[Mutley2]

Cheers for the link, not got any prob (yet) but good to have a read, many thanks...

[cjcj1949]

Perhaps this should be a stickey???