Swash MG or not ?

[scallybert]

Metal gears are significantly more expensive; the gears can still get damagd in crashes; and (maybe the killer) seem more likely to damage the head, etc in a crash.

So I'm wondering if it might make sense to use non-MG swash servos ?

Pretty much 'sacrificial gear-sets', IYSWIM.

I guess the crux is whether the plastic gears will be strong enough not to fail in non-crash operation ?

[Boggy]

are they prone to damage the head? maybe the odd popped link or ball snapped off in a grip etc would be more apt. using or expecting the servo's to be the weak point is a costly way of keeping your self flying Scally

[tonystevens]

from my experience with crashes and ive plenty of it lol metal gears havent been a problem.ivefound that the plastic type servo horns have snapped or ball links have popped off.
ive never broken or bent any metal head part in any crash(flybar and main shaft obviously) and i think this is down to the plastic 'weak link'.now if you have the metal gears and the metal quk type servo horns you would probably do a lot more damage imo

[glen_j]

i've never broken a metal geared servo in the 2 years i've been flying, i have broken plenty of servo horns and had links that pop off though, its normally the links that are a weak link saving a lot of damage in a crash i have seen plenty of plastic gears break in a crash in addition to all of the parts that break in a normal crash and so it ends up costing more and takes longer to fix with plastic gears than with metal in the long run

[scallybert]

I've worked on 2 crashed G5s:

* Mine from May - main blade, main-shaft, flybar. HS-65MGs fine.

* Crashed one I bought for spares - 2 - 3 HS-65MGs with stripped gears, a lot of the head doesn't seem 'right'. One mixer arm seems to bind.

TBH, I don't know the exact history of the 2nd G5, but the metal-gears don't seem to have helped, and may have led to more damage.

In the first case, it's possible that non-MGs would have failed. That aside, it seems that MGs haven't given an advantage - provided they aren't going to fail in a non-crash situation.

The G5 servo layout is such that replacing broken horns is likely to necessitate servo removal. So replacing non-MG gears isn't that much worse than replacing the horns.

To me, the big question is whether the plastic gears are likely to fail in a non-crash situation. So, anyone had this happen ?

[scallybert]

To me, the big question is whether the plastic gears are likely to fail in a non-crash situation. So, anyone had this happen ?

This is my take (guess) on this:

• The servo motor can't generate enough torque to strip the (plastic) gears. (By design. Probably by a factor of several.)
• Gears get stripped by an external shock loading to the servo horn - probably in opposition to the motor.
• I don't guess this is likely under flight conditions (obviously might happen in a crash; may be more likely with plane elevator, etc servos.

So I'd guess that plastic gears will be okay for normal flight.

?

[tonystevens]

ive had plastic geared servos in the past and have stripped the gears in a crash but never in flight,not to say that others havent though