N5 Pitch set up

[Spanner]

So, after a bit of umming and arring, I took the plunge and bought the N5 Combo from Midland helis Midland Helicopters Ltd HeliKits_Synergy .

I'm impressed, although there are a couple of things that I thought could be improved, if only minor things, but thats for another thread!


So its all builts and threadlocked, and after figuring out the CCPM gubbins in my Tx, I need to set up my collective throws. Right now its +15 -10 degrees and +4 degrees at midstick. How do I adjust this to get +/- 10. My guess is set it at mid stick and adjust the pitch rods coming off the swash so I get 0 degrees at midstick??

Cheers chaps and chapesses

[ROSSCO]

Hi,

The linkage measurements in the manual are quite accurate and should give a very linear pitch setup with 0 degree's at center/mid stick.

Go through the linkages and check they are all set to the manual and that all your pitch curves in the Tx are neutral. It sounds as though the 3 linkages from the bellcranks up to the swashplate are very slightly too long, check these first.

For the 3 linkage rods from the bellcranks to the swashplate you need to be looking at a measurement of 24mm between the ball links.

hope this helps, just give us a shout if you need any further help.

[Spanner]

I thought I'd been pretty accurate with the ball links, vernier calipers no less!! I'll have a butchers tonight at work and go through them all again.

[Planehazza]

A trick I use is not to set it at mid stick (because if you do, you have to put the stick precisely on the line by eye), but instead I set a flat line cruve at 50% so every position on the throttle is exactly 50%/mid stick. Then once the servos are set up and geometry is correct, I set the curves as normal and then do my +- pitch.

[Spanner]

Good call Harry, never thought to do that!

[robgt]

As Harry suggests, setting a 50% pitch curve (or just the middle 3 points) means you don't need to ensure the stick is dead central to set it up.

If you don't want to mess with the curves, you can always use the precise method by flicking through the screens on the Tx to your pitch curves, and using one that is set to 0% to 100%, sewt the stick position to an output value of 50%. On my Dx7 and my DX7SE, that has always been just a fraction above the mid stick marker around the stick

Go for zero in the middle, then dial down the swashmix value until your total pitch is where you want it to be.

Cheers,
Rob

[Tripler]

Spanner.
Interested to se what things you would do to improve the Heli or build.
I know there was a few things I did'nt like with the build and I did'nt like having to
buy 600 skids to make it stick to the ground while spooling up/down.
Also had to put some decent paddles and rear blades on as I just have the standard kit.
Admitted I haven't flown it yet but,,,
For the price!,,,, hummmmm

[Spanner]

Tiddler,

Only niggles, nothing serious.
Firstly spelling and grammar mistakes in the manual!

Some of the pics in the manual are fairly vague, especially to someone who has never built a heli before, ie me! So trying to work out where the faint line goes to that points to something important was a bit of a pain but nothing major.
No end caps on the skids! I spent almost £450 on a kit and the skids look unfinished to me!

I don't have an arbour press, so the bell crank shouldered bearings that needed to be pressed in was a royal pain in the arse. When I tried to fit the bell cranks, the screw would bind on the bellcrank bearings. Turned out I hadn't pressed the shouldered bearings in far enough. With everything else that is factory assembled, surely pressing two bearings into place is no biggie?

But, apart from those little niggles, it was far easier than I ever imagined it would be to put together. If I didn't have curious children I think I could have had it built in a night it was so simple. The quality of parts is immense, and the finished heli looks far better in the flesh than any picture on the web. If it performs as well as it looks then it is going to give me a lot of fun!

[Spanner]

As for the pitch setup, turns out you have to be REALLY accurate with your servos being at 90' ! I got them as near as I could, trying all four ends of the horns, and then used a little sub trim to get it perfect, I now have a perfectly level swash, 0' at midstick and +14 -13 at the ends.

Just need to to get the throttle sorted tomorrow, but it looks to be fairly well dialled in already, and work out how to set up my CSM 720 and we're ready for its maiden!

Scared now!!

[v58fuy]

If you are keeping those pitch values rather than dialling down in the swash mix - please check for binding of the washout guide pins on the swash, when pitch and cyclic are added together.

David

[Spanner]

Thanks for that David, I have no binding issues at all with the settings as they are at the moment, but I'll be dialling them down a little to suit my basic flying skills!

[Tripler]

If you are keeping those pitch values rather than dialling down in the swash mix - please check for binding of the washout guide pins on the swash, when pitch and cyclic are added together.

David

Yes I noticed this when I checked for binding and had to dial down in the swash to free it off.
Bit suprised as I'd followed the measurements to the mm,
Using my Futaba swash mix I can't go above 60% without binding on the pitch and cyclic,
Hopefully maiden it tomorrow fingers crossed

[Spanner]

Yeah, 65% and it binds at the top for me

[Tripler]

Yeah, 65% and it binds at the top for me

Spanner
I checked everything again and still had binding of the washout guide pins on the swash, when pitch and cyclic are added together.
I had to move all 3 servo arms back one spline to get full clearance at full pitch,
Then had to reset all my pitch curves,
90deg at 0 center stick def does not work with the manual linkage settings.
Going to start a fresh doing it my way when I get chance.
i.e when my TX pitch settings show 0 the blades are at 0, and no binding at full pitch

[Spanner]

Mines binding on the head, so we're talking +14 degrees, way beyond anything I'm going to need in the near future!!

But thinking about it, it may be the washout pins, I'll look later, too many Grolsch to be fiddling with helis!