Servo Rod Length

[keving]

Mine are 77mm, I think that's too long. When I move my TH stick all the way down of that I can reach the minimum pitch one the Pitch Adjuster, my servo arms are almost straight up and down and when I go full pitch my servo arms are parallel with the ground with all kinds of room to move up. What length are y'all arms from tip to tip of the connectors.

Thanks for your help.

[hexhome]

My rods are 67mm center to center. The manual says 77mm tip to tip. My servo arms are 13mm center to center (ie. effective length rather than actual length). The servo arms are 90 degrees to the servo with the servo centered.
Not able to be absolutly accurate (I don't trust pitch gauges yet), but this gives me a pitch of -2 at bottom, +5 at the middle and +15 at the top.

[Hooloovoo]

The servo rod length will depend on what servos you are using and how you mount them. The idea is to get the distance from the bottom of the swash to the upper bearing plate to be 17mm at midstick. It doesn't matter what the rod lengths are as long as you get that condition to be true.

I think it states that in the manual doesn't it? The 77mm is only an estimate?

[hexhome]

Absolutely true. The best way is to cut a 3 sided'box' of 17mm height and place it between the swash plate and top bearing. I also have one of 22mm and 12mm so that I can check that the swash plate stays level at all pitch settings. This is a useful link albeit for a particular radio setup. http://www.dream-models.com/eco/radio-6XHs-ff6.html
However, I believe that all servos rotate the same amount (except retracts) and therefore the length of the servo arms and rod lengths are an equally valid method.

[ QUOTE ]
Absolutely true. The best way is to cut a 3 sided'box' of 17mm height and place it between the swash plate and top bearing. I also have one of 22mm and 12mm so that I can check that the swash plate stays level at all pitch settings. This is a useful link albeit for a particular radio setup. http://www.dream-models.com/eco/radio-6XHs-ff6.html
However, I believe that all servos rotate the same amount (except retracts) and therefore the length of the servo arms and rod lengths are an equally valid method.

[/ QUOTE ]

The reason that different servos may require different rod lengths is that the position of the servo arm rotation point within the case may differ.

Tim

[hexhome]

Yes there is that variable as well, and as I agreed, the best way is to measure betwixt swash and bearing.
Of course the positon of the rotation point would vary as to the mounting point.
As we are talking about starting points here, I still submit that all these measurements are valid and helpful.
The original question was from somebody building their ECO according to the manual and having difficulties. I have guessed that they would like to find out what other people have ended up with as a reassuring double check. That is why I have responded to the original question in the same terms as it was asked.

hi
the arms should be at 90 degrees to the servo case at mid stick

[keving]

I thought the Piccolo side of the house was fast. I posted this right before I went to bed and you guys just went at it.
Thank You Very Much for all of your help. I'm going to take all of my push rods off and shorten them from 77mm to about 67mm that should be a big help. Because right now when my servo arms are at 90degs I'm at full pitch with full pitch being ~10 or 11 degs. Now I have something to work on. [img]/ubbthreads/images/graemlins/grin.gif[/img]

Thank all of you for your help.

Kevin

[keving]

Hooloovoo

What kind of flight times are you getting with your sport motor and at what headspeed are you getting? I have the same motor and pinion. I'm not sure what my TH Curve should be. Right now I have 0, 85, 90, 100, 100

ECO 8, Sport Motor, 12tooth Pinion, GP3300mAh, Pegasus 35P ESC, Airtronics RD8000TX

That's my setup, I guess I should put all of my helis at the bottom with the signature stuff.

Once again, thanks everyone.

Kevin

[Hooloovoo]

[ QUOTE ]
What kind of flight times are you getting with your sport motor and at what headspeed are you getting?

[/ QUOTE ]

I'm getting 5.5 minutes with my rather heavy training gear on a 2100mAh pack. I'm expecting it to go up to six maybe even seven minutes when I take the gear off.

Head speed I would say max is 1200rpm, but I haven't measured it.

[ QUOTE ]
I have the same motor and pinion. I'm not sure what my TH Curve should be. Right now I have 0, 85, 90, 100, 100

ECO 8, Sport Motor, 12tooth Pinion, GP3300mAh, Pegasus 35P ESC, Airtronics RD8000TX

[/ QUOTE ]

My throttle curve is similar to yours, not exactly the same but it's around that. As you know you have to have the hover throttle up fairly high to get a decent headspeed. I would expect 8 or 9 minutes from your GP3300?