Servo Installation Warnings

[Mike2112]

Originally Posted by 4DPILOT

i just had my 450 Pro crash real hard due to cyclic servo failure in flight no chance

but those had 300+ flights so i guess they were about to die no matter what

(5065Mgs was what i've used)

servo stuck in flight sucks its almost a complete loss nothing left
will get the same hitecs now cause all 3 are dead and will take care on how i mount them

Originally Posted by recurry

Everything has a life limit. 300 flights seems darn near incredible! I've seen people advertise used servos with "only" 75 flights on them. Depending on the type of flying that could easily be worn out. The question is how to tell when theve reached their lif limit and the decide what your philosophy is: A. Fly them into the ground (literally) or B. Replace them at a point where they are still fully functional but approaching their life limit. I know that on my 550 and any ship I get that's larger it's going to be "B". Those machines are just to deadly to fly and know that it could have a catastrophic failure unannounced.

Negative! I have some 5065s with 1,000+ flights on them and they work fine! Sloppy as a $1.00 curbcrawler but they are still going. I do feel the heli has become considerable harder to hold in a respectable hover. Just my .02

[cpmboy]

hi Guys,
Just bought 65MGs servo to replaced my dead 450 pro aligns cyclic servos. Just 2 questions:

1. Which arms to use (single/duo/four arms)?...and
2. Balls at which hole (from center)?

thank you.

[jessey]

While doing my first 450 pro v2 3gx frame assembly I noticed that servo mounting holes distance differ by 1 mm:
pitch/aileron holes are 28.5 mm appart (matching servo holes perfectly)
elevator holes are 29.5 mm appart (1 mm too wide, stressing the servo case)

Anybody noticed the same ?

[lankey]

Originally Posted by cpmboy

hi Guys,
Just bought 65MGs servo to replaced my dead 450 pro aligns cyclic servos. Just 2 questions:

1. Which arms to use (single/duo/four arms)?...and
2. Balls at which hole (from center)?

thank you.

If I remember the four armed ones are thinner than the single/duo arms. Therefore avoid them if you can as you'll get more flex. The single/duo arm holes are spaced the same. Use whichever gives you the best 90° fit, and trim if required.

Ball distance 16mm out (second to last if I recall).

[lankey]

Originally Posted by jessey

While doing my first 450 pro v2 3gx frame assembly I noticed that servo mounting holes distance differ by 1 mm:
pitch/aileron holes are 28.5 mm appart (matching servo holes perfectly)
elevator holes are 29.5 mm appart (1 mm too wide, stressing the servo case)

Anybody noticed the same ?

Had the same issue on my V1! Elongated the servo mounting holes with a needle file to fit.

[archipelagoo]

I wish I would have caught Finless's warning earlier. One more reason to switch the homepage to Helifreak.com!

Anyway, about a year ago, I was assembling the 450Pro with MKS DS460s on the cyclic, and noticed that there was no way to pre-assemble the bearing blocks with the servos (even loosely) and have a chance of the frame holes aligning. Probably should have been my first clue. Anyway, torqued, twisted, and secured with a washer for good measure, and sure enough, one of the servo's motor failed (front right) while I was banking low and fast.

I'm guessing the failure was due to stress on the servo case as Finless described.

Gary in Orlando
Archipelagoo in HF

[cpmboy]

Originally Posted by lankey

If I remember the four armed ones are thinner than the single/duo arms. Therefore avoid them if you can as you'll get more flex. The single/duo arm holes are spaced the same. Use whichever gives you the best 90° fit, and trim if required.

Ball distance 16mm out (second to last if I recall).

Ok..all of my balls are at the 3rd hole frm the center.....the heli flew nicely..no problem atm...but it looked like the linkage rods is not perfectly straight upward to the swash....if I move it to the 2nd hole (frm center), I think I can get all three perfectly straight upward but maybe I'll lose some advantages if Im doing this?......

[lankey]

Originally Posted by cpmboy

Ok..all of my balls are at the 3rd hole frm the center.....the heli flew nicely..no problem atm...but it looked like the linkage rods is not perfectly straight upward to the swash....if I move it to the 2nd hole (frm center), I think I can get all three perfectly straight upward but maybe I'll lose some advantages if Im doing this?......

What distance out is that third hole from center?

[hoot]

Bob talked about why we may be burning up MG 5065's. Although I think they don't burn up anymore, the first batches seemed to have issues. I installed a set in a Rave 450 only to have one burn up just turning the power on for the first time. Also had one heat up bad during flight. This was not an installation issue as the Rave didn't have hole alignment issues.

I don't disagree with Bob's warning at all. You should never stress a servo case during installation. The grind of a flat on a washer is common practice to those who have built kits over the years and not just with installing servos.

[cpmboy]

Originally Posted by lankey

What distance out is that third hole from center?

abt 10mm....

[senoj]

I am having these alignment problems. I am fitting Savox 257 MG's. Savox are, from what I can gather, the manufacturers of the Align servos. I am not having the washer problem but, the frame lines up perfectly without the servos however, when they are fitted, the main shaft binds and just one of the holes in the frame fails to line up with the corresponding hole in the bearing block. I did think about taking a file to the servo mounting holes but came here first. Thanks chaps for the posts, reassured, I now can press on with the surgery.

[holytrex]

I agree with you recurry any heli above 400 size get new ones
I'm going with option B

[hydro_pyro]

Just drill out the holes in the servo mounting ears to the next size. It will go together just fine.

[Mk.32]

Drilling out the mounting seem like the best option? I got those same servos for an 450 build....