Originally Posted by rocketscience

It was the output shaft. It just sheared. I have another one on a flybar'd 450 but once I test that other servo I will probably order a replacement. Just don't trust these anymore. Oh on another note.. when I landed hard one of the other motor mounts had twisted on the boom. I had never installed the grub screw into the motor mount. Maybe that's a good thing? In a crash then the soft metal has less chance of bending?

I had a decent inverted crash the other day and my 306 servo did exactly the same. I thought it was the crash that killed it but if they just fail on their own I'm going to be a bit pi$$ed off that I just got another and a spare!
Currently waiting for time to install the FC protector unit on my rebuild... then it's just wiring it up which is needed.

Originally Posted by thwaitm

I had a decent inverted crash the other day and my 306 servo did exactly the same. I thought it was the crash that killed it but if they just fail on their own I'm going to be a bit pi$$ed off that I just got another and a spare!
Currently waiting for time to install the FC protector unit on my rebuild... then it's just wiring it up which is needed.

Yep it completely failed on its own. I do have that other one I linked earlier on order so we'll see how that one goes, but anything is better than rolling the dice with the 306. Who knows maybe the HV one is better but I'm not going to find out.

Originally Posted by rocketscience

Yep it completely failed on its own. I do have that other one I linked earlier on order so we'll see how that one goes, but anything is better than rolling the dice with the 306. Who knows maybe the HV one is better but I'm not going to find out.

Mechanically I guess the two are identical. Probably some rough machining into a under spec'd alloy.

These servos are probably failing because the dimensions of the pivot are designed wrong.
If you look at the frame from the back you can see the two turnbuckles aren't parallel, this is from an engineer's point of view completely retarded and a major design error.
Throw a couple of washers under the ball joints on the pivot (not the servo adapter) and it should take care of the problem... Or you could just use one and keep the other as a spare.
Seems odd that a decent, strong servo like this would have such a weak spot in the drivetrain.

Originally Posted by AUTO_XX

These servos are probably failing because the dimensions of the pivot are designed wrong.
If you look at the frame from the back you can see the two turnbuckles aren't parallel, this is from an engineer's point of view completely retarded and a major design error.
Throw a couple of washers under the ball joints on the pivot (not the servo adapter) and it should take care of the problem... Or you could just use one and keep the other as a spare.
Seems odd that a decent, strong servo like this would have such a weak spot in the drivetrain.

Totally..

See back on post #231 this was flagged as an issue..
That and the incorrect use of a flange bearing for this type of pivot.
Mods that if not done, are now potentially producing failures..

Originally Posted by AUTO_XX

These servos are probably failing because the dimensions of the pivot are designed wrong.
If you look at the frame from the back you can see the two turnbuckles aren't parallel, this is from an engineer's point of view completely retarded and a major design error.
Throw a couple of washers under the ball joints on the pivot (not the servo adapter) and it should take care of the problem... Or you could just use one and keep the other as a spare.
Seems odd that a decent, strong servo like this would have such a weak spot in the drivetrain.

Based on the reviews on HobbyKing -- if one puts any stock in them -- these servos fail in other applications as well. I'd guess it's mostly a servo flaw. I'm sure the links could be better but I bet a different servo will have better luck.

Originally Posted by rocketscience

Based on the reviews on HobbyKing -- if one puts any stock in them -- these servos fail in other applications as well. I'd guess it's mostly a servo flaw. I'm sure the links could be better but I bet a different servo will have better luck.

Well crap... I guess that was a wasted $60+ bucks... I noticed my tri had a crunchy servo today when I was playing with the fpv setup, turns out the horn screw had worked it's way out. Glad it didn't happen a few hundred feet up

*Unrelated question* - Why does red loctite taste like cherries? A couple of drops in a Rye + Coke might be pretty good.

received my kit yesterday... it's smaller then I thought.

...and there's a lot of parts will start building soon!

Personally I invest in a reasonable Tail servo as you are asking for trouble buying cheap servos for a part of the airframe that is essential - I use Savox SH-0257 they are fast, centre well and well made - http://www.cmldistribution.co.uk/cml...tId=0000004221

Originally Posted by rumbey

Personally I invest in a reasonable Tail servo as you are asking for trouble buying cheap servos for a part of the airframe that is essential - I use Savox SH-0257 they are fast, centre well and well made - http://www.cmldistribution.co.uk/cml...tId=0000004221

+1, and it fits perfectly in the existing servo cutout...

Originally Posted by rumbey

Personally I invest in a reasonable Tail servo as you are asking for trouble buying cheap servos for a part of the airframe that is essential - I use Savox SH-0257 they are fast, centre well and well made - http://www.cmldistribution.co.uk/cml...tId=0000004221

For really expensive or important stuff I do use better servos. Name brand, better history. But you know.. this 306 isn't all that cheap. I think when I first got one it was $21.. just a few $ less than an Align ds420 on ebay which is used on the tail of some of their kits. And I believe the Align servos are made by savox. I love align servos .. good price, great performance.

I'd actually like to figure out a way to frame mount a larger servo like a ds520 and use a carbon pushrod to pivot the tail motor. Just don't have the time to mess with that.

Originally Posted by rocketscience

For really expensive or important stuff I do use better servos. Name brand, better history. But you know.. this 306 isn't all that cheap. I think when I first got one it was $21.. just a few $ less than an Align ds420 on ebay which is used on the tail of some of their kits. And I believe the Align servos are made by savox. I love align servos .. good price, great performance.

I'd actually like to figure out a way to frame mount a larger servo like a ds520 and use a carbon pushrod to pivot the tail motor. Just don't have the time to mess with that.

The Carbon tail rod is an interesting idea. I know the Multiwii scarab has 2 rotating front arms and I've seen other kits with rotating tail booms. They all had landing skids of some type to free up the rotating booms.
H

Originally Posted by AUTO_XX

*edit* I just got back in from flying the tri on an 8000mah 3s.
The flight characteristics were basically the same, just a little slower. Hover was roughly the same position on the stick.
2200mah - 12 minute hover
5000mah - 20 minute hover
8000mah - 22 minute hover (with a bit of wind and a bit of playing)

So it looks like the sweet spot is 5A batteries with 11X4.7 props...

8000! wow, that's got to be a heavy battery. I don't think I'd have the focus for 20+ minutes of flying. I think my brain starts to struggle at about 10min of intense flying or wonders off out of boredom.
3300mAh in free flight , ziping around, gives me 10 minutes at 80% consumed.
I may try a 4000-5000 based on your test. You also have big motors on your Tri 35-36 If I recollect.
H

Originally Posted by eirikso

Just posted a description of how I fixed the sloppy tail servo mechanism.

Simply added TWO thrust bearings and it turned into a perfectly tight and stable mechanism:
http://eirikso.com/2012/10/20/hackin...lon-tricopter/

Thanks a lot for this mod. It makes all the difference, I imagine that this will be incorporated in V2. Great stuff.

Im flying mine with the HH2.0 V1.4 and DJI 2212 920 kv motors on 3S.

It flies OK but isnt amazing. Wondering who makes the best flight controller for around $200 USD fir tricopters?

Looking for something relatively easy to setup with a Naza style autolevel.

Also, can someone tell me the best balance point for this tricopter (with the arms set on the middle settings)