My throttle linkage setup the way my buddy set it up just looks kinda strange to me. Here is what I have right now:

On the throttle servo the ball center to servo horn center is 13.5mm (book says it should be 10mm), End Points are 101 (at) high stick, 89% low stick, throttle trim is at 3/4

On the carb, the ball is in the outer-most hole on the arm.

I have a throttle cut on switch H on my 7chf

I read the "Tip" at Rick's site and I've also read the setup in Ray's book. I'm finding some conflict to setup. Ray's book says to get the ATV's between 55-70% on the top and bottom, keep the ball on the servo horn outward and the ball on the carb arm in.

In the Century instructions, on servo ball should be 10mm out from servo horn center, and ball should be in outer-most hole on the carb arm, pushrod should be 96mm long ball-center-to-ball-center.

The heli hovers well at half-stick (at) +5* at the moment, running a OS 32/No.8 and has had 2 gallons through it.

I'm confused and have a feeling the throttle linkage could be better and the "tune" could be optimized.... help? .. please =\

- Dan Goldstein
Team Revolectrix

The 96mm figure for the length of the pushrod is just a starting point. Don't focus on that. Whatever works is going to be somewhere near 96mm. That's close enough.

keep the ball on the servo horn outward and the ball on the carb arm in.

This advice depends on the heli.. Ignore this for the Hawk.

A perfect setup would have both of your ATV endpoints the same. Still, 101 vs. 89 isn't too bad for throttle use.

[Ball is at] 13.5mm (book says it should be 10mm)

Aww, that's nothing. Mine's at 17mm+.

From looking at your picture, it all looks good to me.

If you really want to make it perfect.
1. Make the endpoints the same +/- ATV.
2. At 50% throttle setting, the angle of the servo arm should be straight up.
3. At the same 50% throttle setting, the angle of the carb arm should also be straight up. [edit:] ...And the carb exactly half open.

That puts your arm setup in the right place... You then need to mess with your throttle curves to get the right throttle setting for hovering at mid stick... the way you like it. That's more of a trial-and-error thing.

-Mark

Mark is right about the servo and throttle barrel arms being straight up (i.e. perpendicular to the linkage between the two) for whatever barrel openning you need for hover. This is as optimal as it gets.

This condition (linkage perp. to arms) provides the fastest linear travel of the linkage for the fixed rotation rate of the servo.... and we want the throttle to be as fast as possible relative to cyclic and collective inputs. The idea is that hover is a neutral condition and when you maneuver the heli (w. cyclic or collective) it will require either more or less throttle than for hover. The best case scenario is to have the throttle inputs lead the cyclic/collective inputs.

HIH,
Steve

Ray's concept is to make the throttle reaction as fast as possible. Part of this is so that when you increase collective the throttle will "lead" the collective. Another way of doing this is to get a faster Servo. But I don't know if that'll make much difference until you are doing a lot of 3D stuff in which case you'll likley be with a difference Heli.

I basically followed Century's recommendations as far as ball placement, then Ray's as far as having the servo arm and throttle arm at the same angle and both of them at a right angle to the control rod at 1/2 throttle. This did mean that I had to change the control rod length but I can't remember what I'm at right now.

Got Money? Send it to me, I'm a Heli Addict.

Just to add to Mark's instructions, when he says 50% throttle setting he means 50% on the curve not necessarily 50% on the stick, unless you have straight curves which is an easy way of doing it. When I setup a new heli, I always use straight curves (0,25,50,75,100) for throttle and pitch and set everything straight (ATVs as close as possible to 100% but equal on both sides...), level and perpendicular at half stick because at that moment half stick is the middle of everything. It is time consuming to get a good combination of ball position and linkage length. Personally, I enjoy that step for many reasons. It's in the comfort of your house, no stress, no cost, the electronics get a chance to prove themselves, cycles the batteries, etc and I know it's the last step before the big day.

The time spent making everything "square" will pay off on the long run. Plus, all the other adjustments will be made in the transmitter. It's also easier for someone else to help when the model is physically well setup.

Bruno

Bruno, what I've done is to set up a second model on my radios for "0" setting. As you've said, the pitch and throttle curves are completely linear from 0% to 100%. That lets me set up (or recheck) things, especially if I've had a crash.

Got Money? Send it to me, I'm a Heli Addict.

I'll double check everything tonight..

Mike Foy.. I see you have the billet aluminum carb arm, how was that with adjustments for the throttle barrel opening compaired to the regular arm? Why did you buy it?

..also, what muffler is that on there and did you see a improvement over the stock black torpedo?

- Dan Goldstein
Team Revolectrix

go to Rick's in the link, once in Rick's click on "Tips" once in tips click on and read "setting up your throttle", read it a couple times if you need too, it may help,,,

http://www.rcheli.com/

Jim

It clamps onto the carb arm rather then screws on. I was always nervous about the screw comming loose and the arm slipping. This clamps on so it cant fall off.

The muffler is a Centruy torpedo muffler (CN3033)
It is great, A LOT quiter and more power. the Stock one is hollow, and loud, and sucks a lot.

mike

hmm, that muffler is interesting ... BUT...

I'll save my pennies for the Toki 40 with muffler, right now $175 at MRC

- Dan Goldstein
Team Revolectrix

ok, just re-tweaked some stuff on the throttle...

in my throttle curves, half stick was at 55%, I changed that to 50%, then verified that at half-stick the servo arm and carb arm were both pointing straight up and 90* to the pushrod, all good there... then I went into the End Point setup.. with 3/4 trim (to open the carb enough to get it started), I have End Points set at 100% on both sides with no binding and full WOT and full closed. I bumped the throttle trim up to 3/4 so the carb is open just enough to start. Then I setup the TH-CUT to throw the carb closed.

So far as I can tell, my setup now coincides with the Tip at Rick's and any throttle/head speed adjustments I need to keep a good hover/transition speed I'll make in the Throttle Curves?

Rick's suggested that hovering throttle would be 60-64%, mine is still at 50% for now..

- Dan Goldstein
Team Revolectrix

Two things from your last post:

1) I don't bother using the trims to open up the throttle rather I just use the throttle curve and keep it at 10% on the low end.

2) Ray's Heli book suggests hovering at 3/4 throttle because once you move to a 3D inverted setup you'll hover at 3/4 (and 1/4 when inverted) so when switching over from Normal mode to IdleUp, you'll already be at 3/4 throttle and there won't be a "jump" (or a "dump" when switching back). I've been idling around 1/2 throttle as at my early learning stage I prefer to have more throttle movement to work with but as I progress into loops and stuff I'll be changing my curves so that my hover position in "N"ormal mode = my hover position in IdleUp = my hover position in Hold.

Got Money? Send it to me, I'm a Heli Addict.

I've been idling around 1/2 throttle

(I think you mean "hovering.")

i've debated about switching to hover @ 3/4 stick... but.. I haven't switched over yet because I'd lose throttle resolution, there is a much shorter range between 3/4 and full stick...

once i get to the point where I start doing FF and mild aerobatics I'll reconsider switching.

- Dan Goldstein
Team Revolectrix