Aluminum Servo mounts for 120 degree mixing on ECO-8! - RC Groups
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Jan 12, 2002, 12:06 PM
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Aluminum Servo mounts for 120 degree mixing on ECO-8!

Hi guys, I have just finished my ECO-8 and am waiting for the Mega motor to come in. Anyway I made these really neat aluminum srevo mounts that give nearly perfectly vertical linkages.
Go here for pictures

What do you guys think?

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Jan 12, 2002, 04:11 PM
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Aluminum Servo mounts for 120 degree mixing on ECO-8!

I too have created aluminum motor mounts for 120 CCPM for my Eco of a different design. However, now that I want more negative pitch, I have put longer servo arms on and the servo arm balls are no longer directly under the swash balls. I need to re-engineering.

Anyway, I was wondering exactly how long your servo arms are from rotation axis to ball center?

And, with your current servo arms, do the mounting brackets rub against the heli body?

Thanks, Russ Tront.
Jan 12, 2002, 05:23 PM
Registered User
No, the mounts or servos do not touch the body. I measured the servo arm, from center of the rotation axis to the center of the ball it is 13mm. Thats plenty long enough for right now since I won't be doing any areobatics soon. Those are the arms that come with the HS- 81 servos.
Jan 13, 2002, 11:03 PM
Registered User
In order to do aerobatics I need a fair amount of negative pitch (currently -5 degrees but I could go to -9 with my current arms). With the standard head, I am using 19mm long servo arms (axel to ball center). I bought some massive 'super strenght' servo arms from Dubro. You can get them in different flavors for different brands of servos. I cut a lot of the extra material off, but keep enough length to give me 19 mm. However, I suspect if I mounted my servos the way you do, but far enough out to allow these 19mm arms room, I might hit the body. I have another idea in mind for mounts and will say something to the group if it is sucessful.

You should all note that to get even 5 degrees of negative pitch on the standard plastic head (and still retain aileron control without jamming) I had to shorten the very short push rod between the seesaw and the mixing arm. However, this is not shortenable without cutting off some material and weakening it because there is not much for the threads of the rod to bite into any more. So I made the hole that is threaded into deeper, until it almost breaks through to the ball.

For real aerobatic, you probably want to go to the aluminum head. I am trying to put my new aluminum head together now. Regards, Russ Tront.
Jan 14, 2002, 08:23 AM
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ECOFlir's Avatar
John H,
That's a nice and clean looking mount. How much extra weight did that apply?
Jan 14, 2002, 09:19 PM
Registered User
I just shortened the link between the flybar and mixer lever and I now get +11 to -10.

The mounts weigh 5 grams each. So there not really a significant weight gain.