FlyMentor Throttle Unstable

[boowho]

Yes..... Since installing FlyMentor on my Trex 450, the motor control seems "spastic".

Some times with a tiny change in stick position, the bird will jump upward several feet. On the other end, it will (again, with very small THR stick position change), "bounce" off the ground (if at low altitude).

Anyone else seen this?? Maybe my FM gain is set to high???

Boowho??

[Ivor Hill]

Originally Posted by boowho

Yes..... Since installing FlyMentor on my Trex 450, the motor control seems "spastic".

Some times with a tiny change in stick position, the bird will jump upward several feet. On the other end, it will (again, with very small THR stick position change), "bounce" off the ground (if at low altitude).

Anyone else seen this?? Maybe my FM gain is set to high???

Boowho??

If the gain is to high it will cause the heli to rock side to side and front and back it will not cause changes in altitude.
FM is not connected to throttle in any way, it is completely separate so cannot cause changes in throttle. It sounds like it is to sensitive around mid stick.
It may be a problem with the ESC but imo it is more likely to be a TX setting problem.
Try changing the throttle and pitch curves. For normal flying try 0-75-75-75-100 throttle and 45- 67-75-87-100. Also if you are using expo make sure it is set in the correct direction.

[boowho]

Originally Posted by Ivor Hill

If the gain is to high it will cause the heli to rock side to side and front and back it will not cause changes in altitude.
FM is not connected to throttle in any way, it is completely separate so cannot cause changes in throttle. It sounds like it is to sensitive around mid stick.
It may be a problem with the ESC but imo it is more likely to be a TX setting problem.
Try changing the throttle and pitch curves. For normal flying try 0-75-75-75-100 throttle and 45- 67-75-87-100. Also if you are using expo make sure it is set in the correct direction.

Thanks mate....... I'll give it a try

Boowho??

[boowho]

IVOR:


Here are my current curves. The pitch curve is completely linear as specified in your tutorial.

Thanks

Boowho??

[Ivor Hill]

Originally Posted by boowho

IVOR:


Here are my current curves. The pitch curve is completely linear as specified in your tutorial.

Thanks

Boowho??

The linier pitch curves specified in the tutorial is for setting up FM, when set up is complete you can change it to whatever you want.
The pitch curves I recommended above are for normal flying, no inverted flight.
The pitch curve 45-62-75-87-100 would give you about -2 to +11 degrees and the throttle curve 0-75-75-75-100 would give you constant speed around mid stick so the heli would be less sensitive around mid stick because only pitch is being changed not pitch and throttle speed.
Those would be my normal curves but if I felt I needed a bit more power I would change the throttle curve to maybe 0-85-85-85-100 or maybe less power 0-65-65-65-100. You can also use some expo to reduce the curve around mid stick to reduce sensitivity, I normally do because I like a lot of control when hovering.
Bare in mind that I am a scale flyer, no stunts and is the way I would set up a heli for a new flyer. Hope this helps.

[boowho]

Originally Posted by Ivor Hill

The linier pitch curves specified in the tutorial is for setting up FM, when set up is complete you can change it to whatever you want.
The pitch curves I recommended above are for normal flying, no inverted flight.
The pitch curve 45-62-75-87-100 would give you about -2 to +11 degrees and the throttle curve 0-75-75-75-100 would give you constant speed around mid stick so the heli would be less sensitive around mid stick because only pitch is being changed not pitch and throttle speed.
Those would be my normal curves but if I felt I needed a bit more power I would change the throttle curve to maybe 0-85-85-85-100 or maybe less power 0-65-65-65-100. You can also use some expo to reduce the curve around mid stick to reduce sensitivity, I normally do because I like a lot of control when hovering.
Bare in mind that I am a scale flyer, no stunts and is the way I would set up a heli for a new flyer. Hope this helps.

Thanks for the additional info. For the first time today I flew the bird other than in a hover. The dern thing "got away" from me and flew almost out of site before I got it under control; it was also climbing like a bat outta hell. So I got it turned toward me and pushed heavy forward stick as it was coming back and it came down just as fast. Then heavy back stick to bring it out of the "dive". Rotors made a neato noise at that point!!!

Anyhow, I got it back using my fixed wing skills from almost 40 years ago. Even managed a high bank turn onto final approach. Unfortunately, the landing was a controlled crash, but with minimal damage.

Boowho??

[pril250]

I am almost certain the BEC within your ESC, if that is the combo, can't take the load, A 2 or 3 amp BEC is not enough to run FM, you need at least 5A in my experience. You may need to use an external BEC.

[boowho]

Originally Posted by Ivor Hill

The linier pitch curves specified in the tutorial is for setting up FM, when set up is complete you can change it to whatever you want.
The pitch curves I recommended above are for normal flying, no inverted flight.
The pitch curve 45-62-75-87-100 would give you about -2 to +11 degrees and the throttle curve 0-75-75-75-100 would give you constant speed around mid stick so the heli would be less sensitive around mid stick because only pitch is being changed not pitch and throttle speed.
Those would be my normal curves but if I felt I needed a bit more power I would change the throttle curve to maybe 0-85-85-85-100 or maybe less power 0-65-65-65-100. You can also use some expo to reduce the curve around mid stick to reduce sensitivity, I normally do because I like a lot of control when hovering.
Bare in mind that I am a scale flyer, no stunts and is the way I would set up a heli for a new flyer. Hope this helps.

I tried modifying pitch curve from totally linear to -30 -15 0 50 100

After I did this it make my left/right and fore/aft cyclic unsymmetrical; in other words moving stick left did not give as aggressive servo movement as moving stick right. It's "lopsided" so to speak.

Perhaps Ii don't know how to set up my mixes for flymentor. I'm attaching a png of ONLY my CH 1, 2 and 6 mixes. Obviously I have others, but I wanted to be as simple as possible. I use the standard Futaba channel assignments.

My pitch curve is referenced as C4 and defined as in my message a few messages back in this thread. Turnigy 9X using er9x firmware.

I'm unsure if linking the same pitch curve to each of the three swash channel is the correct way to do it.

Boowho??

EDIT: I think I just figured it out.

In er9X, you need to define an unused channel as collective (on heli setup tab).

I just did this now; it was previously undefined.

I used channel 11.

Then in channel 11 mix I set +100%THR Curve C4, and removed the C4 reference on Channel 1 2 and 6.

[Ivor Hill]

Sorry, not familiar with your TX I use Futaba but non of this makes any sense to me. Mixing should be switched off in the TX, all mixing is done in Flymentor. Setting mixes in both TX and FM will just cause conflict. The throttle ( channel 3) should be connected as it was before fitting FM, it is a direct connection and does not go through FM.