HELP...Pitch /Throttle Curves

[phil]

Hi im new to helis and need a little help...
Learned to fly on a sim and now i just built a Raptor 30 v2 and am using a FF6 heli set.
managed to get it hovering ok but not sure about the pitch/throttle curves???
I only set it up using the gauge printed on the side of the heli frame..and mechanically setting throttle to idle/hover /full.
Something not quite right though.. My trany has too many functions i dont understand and even if i did ii dont know what values to enter???????
there are 3 functions i think are linked to my problem..(Hovering Pitch / Hovering Throttle / and Pitch Rate (normal, Idle up, Hovering.) IM LOST.
Any help would be appppppreciated.
Cheers.
P.S. Tried downloading the P/T Curves 5 point but dont have spreadsheet so couldnt open it............

[Stuart]

Hi Phil

Welcome to the site....

Okay the reasoning behind the pitch & throttle curves is to try and find a balance between the two that gives you a constant headspeed circa 1550 if my memory serves me right 6 degrees pitch is hover for the raptor 30.

The Futaba FF6 has a 3 point curve settings for throttle and pitch, the hover rotory switch allows you to adjust slightly the point two within the pitch curve to help find that sweet spot.

In my pinion I would set your Raptor 30 mechanically up based on the 3D setup thus giving you a -10 and +10 pitch range. Making sure that all ATV's are at 100% for pitch and throttle and the arms are positioned to give a true arc from the servo's through to the bellcranks and onto the swash plate.

Once you set up your heli perfectly, then do the following if you using the card board pitch gauge, it did come with the V1 version I'm not sure if it come with the V2 version.

Put you throttle at the very centre and make sure that you get 0 degrees on the blades this should = 50% on the pitch curve setting, if so good... if not adjust the link to get it spot on.

Now drop the stick and now adjust the pitch curve % till you reach about -3 pitch or as close and you can make it with your pitch gauge.

Now you'll have set both the bottom and mid stick positions, not put the stick to 3/4 position, this is your hover position and your looking to get a 6% degrees pitch here, if its not then the only option you'll have is to move the top % to achieve this, once reached move the stick to the top and see what the top pitch range is....you should find that its between 8-10 which is fine.

Thats you pitch set.

Now onto the throttle curve.

Again with the ATV's set to 100% bottom = closed with trim right down. Move the trim to the half way. Now move the throttle to the top sand make sure that it opens all the way, without any binding.

At half throttle the carb wants to be half open and the pitch should sit on zero, if not adjust the mid point curve to give you 50% at 3/4 throttle stick position it should be about 3/4 open and the pitch at 6 degrees.

You should now be ready to start your first flight, its all fine tuning after here.

There is a train of thought that you should setup your heli pitch to be -3 to +8 for beginning and then re-configure your heli later to open up the parameters.....In my opinion I'd rather use the technology to open the flight envelope than have to sit down and re-setup the whole pitch and throttle curves.

I'm sure Raptorite will have some great tips for the Raptor 30.....

What engine have you got in it ?

You'll also find some good tips here on the Raptor 30

http://www.raptortechnique.com/

[G-DAVE]

3D setup's for beginners ???
A beginners low pitch should be know more than -1 for that occasion when panic sets in and the instinct is to bottom the stick .
Dave D

[Raptorite]

Hi Phil,

I think Stuart has this one fairly well covered, there are a few more tips I would like to add though;

When you install the collective pitch servo, mount it in the opposite way to it says in the manual, in other words, such that the horn or splined output from the servo is closest to the front of the heli with the arm pointing towards the back. Also screw the ball on the inner lug on the collective lever, closest to the main shaft, this is the 3d position so with the servo position reversed you will find that the rod remains nice and virtical through its movement.

Once you have done this set the length of the rod such that the pointer on the collective lever is pointing to the 0 degree mark on the little gauge on the frame. Then make sure that all the levers on the rotor head are parallel and symetrical and the washout arms (just above the swash plate) are level. Now set the long rods from the swash plate to the mixing levers right at the top of the rotor head so the blades are at 0 degrees. You will then be able to get equal pitch movement either side of 0 degrees.

The only other thing to add is that having set the pitch range mechanically to -10, 0, +10 using the ATV's, set point 1 on the pitch curve to represent no more than -4 degrees on the blades, start with 35% and go from there. Also set the top stick pitch to be no more than 8 degrees on the blades, so set the top point in the pitch curve to be about 80% and work from there.

For your first hops and hovering you shouldnt have any more than -4 at the bottom and +8 on the top at most, as you get more proficient at hovering you can open up the pitch range simply by increasing the pitch curve rather than having to make anymore mechanical adjustments.

The only other building tips are to make sure you use plenty of locktite on all the metal to metal fastenings like engine mounting bolts, clutch mounting bolts and particularly the nut on the top of the crank shaft on the engine and those long set screws that hold the tail blade grips to the hub.

The other thing to look out for is the white gear that drives the tail belt, it should spin freely so with it all assembled you can hold the top main gear with one hand and spin the rotor head with the other, if it seems tight and most are when they are new, take the white gear off and run some sand paper round inside it until it stops binding against the outer sleeve of the one way bearing underneath.

Finally, make sure the thrust washer is installed on the bottom of the starter shaft inside the clutch, it sits just above the c clip that sits in the groove on the bottom of the start shaft, it is easily missed out and if it is will cause all kinds of binding problems with the clutch as it hits the top of the clutch bell.

Best of luck with the build and setup

Cheers,

Pete.

[phil]

Hi lads thanks for the help managed to sort it, main problem was my ff6 trany does not have pitch curve settings ( i couldnt find them......) this got me confused.
Anyway managed to set it all up and am up and away.
Cheers.
phil.

[Dedcalm]

The FF6 does indeed have both pitch and throttle curves (3 point). These are fine for a basic config. I used to fly a FF6 with my Nexus. I will look up how to get to the settings when I get home for you...

Rob

[Dedcalm]

I guess I am slightly mistaken, what you can change is the throttle for Normal, Idle up and Hovering to give you the V curves in Idle up thus enabling 3D



there is a copy of the manual available here,

http://www.futaba-rc.com/manuals/6xas-hs-manual.pdf

check out page 51 onwards for an explanation of the PI- options.

If I get time to tinker with the Nexus tomorrow I will let you knwo if I remember anything else usefull...

Rob

[jimbob]

Its interesting to see advice to a beginner about pitch curves etc without knowing what kind of flying they will eventually be doing.

I have trawled through loads of topics trying to find more about pitch and throttle curves - I am a relative newbie to helis, and I want to set up my R50 better.

I however do not want to do 3D - I have no intention of inverted hovering or anything else like that - and I suspect that no beginner would want to either.

Now I know a little more about helis, I can understand most of the advice given, and I would like to make this point.

Most of the people actively involved in these forums are real heli enthusiasts - which is great, but also, they are often 3D enthusiasts too - which is a little scary.

If a chap came on with a R60 he'd just fitted a scale fuz to and wanted to fly his scale crop duster sedately around the field, but just asked for info about pitch and throttle curves - he would have a right old mess if he gave himself -10' of pitch.

So I think it is valid to recommend setting the pitch up to say +8/-2 intially, and then have to change it later, because that way a person will learn a) what it all actually does, and b) not have some potential monster on their hands whilst trying to learn to hover.

Just my thoughts - no offence to anyone intended.

Now, what should my R50 curves be set to for sport flying?

[Ade_Law]

there is more to negative pitch than inverted. You have to think about autos (emergency or purposeful).

The major advantage of having a symetrical pitch curve centred around zero is that you can do fast (for fun or emergency) without the motor cutting back to idle and if you do come back behind the 1/4 point you arent going to be loosing much headspeed.

some will say to just use an idle up but personally I dont like people using idleups unless they really need them. or they have a governor and need to get into the habbit.

Also there is the important thing about recovering to inverted. If you dumb thumb it through a loop/roll and end up inverted at low level there is nothing worse than hitting the end stop on the stick and it still sinking gently to the ground.

For absolute noobs on training skids then i set them up for 0 degs at full back stick it limits the potential for those times when they chop the throttle. But once they get off the skids i try to move them on to the full range through a couple of steps.

Ade

[jimbob]

Dont get me wrong - I'm not saying that negative pitch is a bad thing per-se - but to give a novice (and that includes me) a 3D setup from the word go to my mind is not useful.

1) a 3d pitch curve might be totally inapropriate for the heli or the flyer, wether beginner or not.

2) they never explore what pitch curves are all about cos someones already told them this is how it should be.

I want more -ve pitch now cos i can fly circuits and I want to option, but i dont think I'll ever need a symetrical pitch curve - thats just not how I'll fly.

Incidentally, how much pitch do I need for an auto? Thats a real question, I;m not trying to make a point

[Ade_Law]

+/- 10degs isnt a "3d setup" its a pitch range that lets you put the model exactly where you want it when you want it. That applies to general flying around just as much as it does to 3d.

-10 degs doesn't make the model shoot into the floor at mach 5 it does make it come down quickly which... trust me... *IS* useful!

even for stall turns a full idle up throttle curve and -10degs is needed in windy conditions to keep the model in the right place when doing it "up wind"

so just because people use the setup for 3d doesn't mean a flier that is doing circuits, loops and stall turns wont benefit from it.

Once one of my customers has mastered the hover I move them onto the full pitch range. Not all in one go, takes a couple of steps but it doesn't take long. I do this because it is easy to get locked into how a model feels and once locked in it can be hard to break the habit. So to save relearning how to fly a full pitch range after habits have been formed i have found it better to do it early.

If your doing circuits you will greatly benefit from a full pitch range.

Ade

[jimbob]

Understood, and agreed.

[wazzer]

I also think that the general idea of setting up the heli mechanicaly to give the full pitch range is to then then limit this range in the TX programming with the endpoint settings

This way a beginner can set a -4 +8 range from the TX

when he then progresses all he needs to do is to adjust the End points in the TX and he has a greater pitch curve to play with

Please correct me if i am wrong as this is how i intend to set my heli up

cheers

[mackem54]

hi wazzer,

my rappy 50v2 is set up to +10 and -10 in the tx but i have limited it in normal and idle up1 to +10 and -4 using the pitch curves,i was under the impression that this was the way to go so as you improve instead of having to reset the pitch you just dial it in on the tx,

[wazzer]

That sounds the most obvious way to me