A little confused on differences in pitch between setup and flight mode

[AgentZero]

I finished setting up my first BeastX and I think I have most things correct, but there's one area that's still puzzling me.

I got step J completed (after reading lots of posts around blue light, red light, etc. etc.)

So Step J is setup for 6 degrees - but when the helicopter is in regular flight mode, I'm getting about 12 degrees cyclic pitch (whether measuring aileron with the blades parallel to the boom or elevator with blades perpendicular).

(This is on a Trex 500 DFC in case that matters).

Two part question

1- Is that normal?
2- If so, do I try to fly with that much pitch, or should I adjust either with DR or endpoint travel in my radio to compensate?

I'm a very novice flyer, so I don't want this thing getting away from me because it has more pitch than my skills can handle.

Thanks in advance for any advice!

[Wsurf]

I'm a little new also but have been flying with the beast for a while. Step J is just telling the Beast that the heli is a capable FBL configuration. Once in flight mode you are flying on whatever pitch and throttle curve you have put into the Tx.

For me, I'm using about -2 to +7 degrees pitch with about 70% throttle max. It is my understanding that all mixing is done with the Beast, NOT the Tx. You adjust pitch in the Tx using the pitch curve but not DR. You would use the Parameter settings in the Beast for a DR/expo type of setting.

[aseejr]

Originally Posted by AgentZero

I finished setting up my first BeastX and I think I have most things correct, but there's one area that's still puzzling me.

I got step J completed (after reading lots of posts around blue light, red light, etc. etc.)

So Step J is setup for 6 degrees - but when the helicopter is in regular flight mode, I'm getting about 12 degrees cyclic pitch (whether measuring aileron with the blades parallel to the boom or elevator with blades perpendicular).

(This is on a Trex 500 DFC in case that matters).

Two part question

1- Is that normal?
2- If so, do I try to fly with that much pitch, or should I adjust either with DR or endpoint travel in my radio to compensate?

I'm a very novice flyer, so I don't want this thing getting away from me because it has more pitch than my skills can handle.

Thanks in advance for any advice!

12 degrees of cyclic is fairly normal. But don't forget when setting up 'Step J' - blades parallel to the tail boom - pitch should initially read '0' - move aileron stick and stop as soon as pitch gauge reads '6' degrees - light should be blue to have "optimum geometry".

Flying with 12 degrees of cyclic is normal BUT what's important is that the swash does not bind - at the collective top and bottom when you move to full cyclic will the swash touch / bottom out? Or at around mid collective and you move full cyclic will the swash hit the main shaft? If it doesn't then, I think you are good to go. If it does then reduce cyclic range.

[AgentZero]

Originally Posted by aseejr

12 degrees of cyclic is fairly normal. But don't forget when setting up 'Step J' - blades parallel to the tail boom - pitch should initially read '0' - move aileron stick and stop as soon as pitch gauge reads '6' degrees - light should be blue to have "optimum geometry".

Flying with 12 degrees of cyclic is normal BUT what's important is that the swash does not bind - at the collective top and bottom when you move to full cyclic will the swash touch / bottom out? Or at around mid collective and you move full cyclic will the swash hit the main shaft? If it doesn't then, I think you are good to go. If it does then reduce cyclic range.

I'm not binding anywhere - I spent a fair amount of time on step L running through all 360 degrees of cyclic input and high/med/low collective and eliminated any binding, so I'm good there. The main thing that threw me is after dialing in 6 degrees of cyclic in step J, I thought that meant I'd have 6 degrees of cyclic when in actual flight mode - not double that! As mentioned I'm a novice flyer, and I just built a brand new heli - so just trying to cover all my bases in the hopes that my maiden flight doesn't go boom! Thanks!

[aseejr]

The way I understand 'Step J' it is not a electronic setup. It is basically just a gauge to tell us whether we need to do mechanical mods / adjustment.

[aseejr]

In step j, at the spot when the pitch gauge reads 6 degrees and you have a blue light - then you have the optimum setup.

[sutty]

Step J has nothing to do with telling the MB how much cyclic you have, it is designed to show the MB how much 6 degrees is, so that it knows how much throw to initially apply for any given requested rotation rate or correction that is required. Thereafter the contol loops itterate this until the requested rotation rate is delivered. During this step the MB also knows if the position to which you have had to move the stick, in order to achieve the 6 degrees, is acceptable, or not, for flybarless operation. Too little stick movement to get there, and there will be insufficent resolution for accurate control by the MB. Too much movement to get there and there will be inadequate servo speed, or overall throw available for use at step L. In the first case this will be displayed as either no light at all, (bad), purple, (not very good), red, (good), and finally blue, (excellent). However, if you go blue very early, although the resolution and accuracy of control required for the MB to operate correctly will be very good, hence why it remains blue, you may have inadequate overall throw at step L, giving you insufficient total cyclic, for if you want an agile helicopter.

Step L is what determines the overall cyclic, but it still has very little to do with how the helicopter will behave, as long as you have enough. The MB is in total control of how much throw it delivers to the blades, and even if you had 18 degrees here, the MB will only deliver the appropriate amount of throw to ensure that the helicopter performs in the way that you have it set-up in the MB. 18 is probably too much for good accurate control, as you would likely have got a purple light at step J, but I mention it just to make the point.

If you choose flight behaviour normal, then the MB will make the helicopter feel tame, and even with 18 overall it would only behave like a helicopter with 6. If you had it set to sport, or higher, then it might behave like a helicopter with 8, or more, with extreme probably being like a helicopter with 10 or 11 degrees. These numbers are not real, I use them just for illustrative purposes.

Having more throw at step L, or when you push the stick over in flight mode on the ground, is not indicative of what it will do in flight, as in flight it will control the amount delivered. What having more than you need here does is allow the MB to deliver the requested rate of rotation, even if conditions are trying to prevent this. Say you request full roll, and in the MB this is set at 300 degrees per second, for the type of flight behaviour you have set, flight behaviour pro for arguments sake, if it doesn't see 300 degrees per second when you give full stick, it will apply more and more and more throw until it does, no matter what the wind is doing.

This is why on the ground, since the helicopter cannot move, the MB goes to full throw, as it is trying to achieve the rate of rotation requested, but it cannot, so it gives more and more and more throw, until it reaches the limits you have set at step L.

As I mentioned my numbers are not accurate here, but should give an idea of what is going on. 12 will not be too agile for you if you set it to flight behaviour normal, or if you set it to say flight behaviour Tx mode, and set your travel adjusts or dual rates down to say 80%. This will behave like a nice gentle helicopter with 6 or 7 degrees of cyclic, but will mean that should the MB need it, for its own correction purposes, it will still have up to 12 degrees to deliver to the heli.

Additonally, having 12 available, means that you can keep tuning the MB up by either going up through the control behaviours, or by adjusting your travel adjust, if you are in Tx mode, so that you will eventually end up with a very agile helicopter when you are ready for it.

More than 12 might not be wise, even though it says you should max it out in the manual, but this is a point that is open to discussion or interpretation. Certainly much higher than 12 at step L will mean that the cyclic is moving too far too quickly, so that when you try and set 6 degrees at step J you will likely only get red or purple anyway. So setting up step J to give 6 at blue, almost directly relates to what you will get at step L anyway, and helps keep it well within acceptable limits.

Not sure if that helps, but I hope so.

Cheers

Sutty

[AgentZero]

Wow - thank you for that fantastic explanation!!! That makes perfect sense and not only answered my question, but helped me understand the overall workings much better as well.

So I guess if crash now, I can't blame it on the 12 degrees of pitch - I'll just have to admit I'm still a newbie pilot

Seriously - thanks again - I really appreciate your very detailed response - it really helped!

[DaveHolland]

12 is good, like Sutty said its just total available to the FBL controller. You wont use all the pitch until you tell it to. I was only able to pull 10 degrees out of the new 700 v3 without binding and its still very agile.

[SilverRex]

Thanks Sutty, really good stuff.....getting ready to set up my Beast and been reading a ton of posts on the subject and to hopefully help me through the "unknowns"...
Thanks for your posts and your time....