|Ben B||22/07/2017 20:43:38|
1399 forum posts
A recently finished a rather expensive E-flite Clipped Wing Cub. It was (past tense) running a 3s system using a stabilised Spectrum rx. I must admit I had a mini coronary at the cost of the E-flite servos so bought some digital hobbyking jobbies at a very reasonable 3 quid a pop.
First time I switched it on the right airelon servo glitched and jammed but ever after seemed to behave well.
I took it down the park the other day and despite being a bit windy all was well. I started tuning in the as3x settings and all was fun.
Tonight given that it had stopped raining I took it out for a flight to test some new as3x settings. Half way through the first flight I did a roll and on exiting the roll it was obvious all was not well. It continued rolling to the right. For a split second I thought "as3X issue". Then realised the flipping servo had jammed on high rates. I tried oppose airelon (the aim being to effectively turn the "up" aerlons into spoilers), down down elevator (to counteract the lift) and rudder to steer and just induced a massive spin. Cut the throttle went it was obvious she was going in but no luck. Nose-in straight into the ground at high speed.
Plane - destroyed
So about £150 of wreckage on account of cheaping out in order to save a few bob.
Now I have no doubt there are some good servos between Hobbyking digital rubbish and E-flite jobbies and I guess I'm going to have to find them.
|Ben B||22/07/2017 20:44:45|
1399 forum posts
So lessons learnt are
1) don't buy cheap rubbish
2) even if it just gives you grief once get rid of it (I'm not sure this rule includes the misses)
|1220 forum posts|
The other thing is that these stabilation systems are ok but if aerodynamics won't fly the plane then the stabiliser won't.
|61 forum posts|
did the servo work ok when stabiliser was off !!!!
|Simon Chaddock||22/07/2017 21:27:29|
5440 forum posts
How long "cheap rubbish" works does rather depend on the duty it is given.
Tiny and very cheap 3.7g aileron servos have been running perfectly for nearly 5 years in my light weight 60" Depron motor glider and have survived a few crashes too but then the ailerons are unfashionably small, very free moving and it flies pretty slowly to boot.
|Braddock, VC||22/07/2017 22:04:39|
1632 forum posts
I find it best to buy one of HK's servo testers and rig up the servos and leave them running for, say, half an hour as soon as they arrive. If they get very warm or display any unwanted tendencies contact HK they will take them back and credit you.
The ones that survive will continue to give good service. I have to say that all the servos I've bought from HK haven't been the cheap little ones, more often than not they exceed 3 Kg.cm and £8 a unit.
Incidentally I started doing this when I bought 10 hitec 322 Hds from steve webb, they all were fine.
|Former Member||23/07/2017 20:35:20|
|1322 forum posts|
[This posting has been removed]
|Percy Verance||23/07/2017 20:42:47|
8108 forum posts
Another *run new servos on a tester for at least 30 minutes* fan here. I bought some small blue cased servos from somehere - HK I think- which got extremely warm after being on the tester. I felt they also displayed too much slop in the gear trains so I didn't use them in a model.
Stick with known reputable servo brands from reputable sellers (to avoid the fakes) and you should be fine.
|Ben B||23/07/2017 22:28:43|
1399 forum posts
Cheers peeps. Sounds like I'm the bleeding edge of retrospecoscope
I'll run my new ones on the servo tester. Just ordered a mini wot4 and a replacement CPC for good measure. I did find I could hybrid my hobbyking motor with a Sunnysky 1900kv motor to create some wierd kind of franskenstein outrunner. Runs at 10A instead of 6A with the stock motor and seems to have more grunt so I'm happy....
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