Mks 95 servos vs clone servo for mini protos

[ebonicrobot]

Wow I never knew RJX made them.

[maarset]

Originally Posted by Napoleon_Tanerite

Friends don't let friends buy clones, especially for a nice heli like a protos.

Always factor in crash damage when thinking about using cheap clone servos.
Sure your saving money buying these servos, but when they cause a crash... well the money you have SAVED on cheap servos goes to repair cost

[gothicbunny]

Originally Posted by maarset

Always factor in crash damage when thinking about using cheap clone servos.
Sure your saving money buying these servos, but when they cause a crash... well the money you have SAVED on cheap servos goes to repair cost

I can do a complete rekit on my Tarot 450 for less than I would have spent on the same MKS servos and still had money left over for another set of KST servos. Even on a mini protos I would imagine it would take several crashes before it became more expensive.

[maarset]

Well, depends on the mini P. Yes it crashes well. But even hard crashes can do in the Side frames and canopy. And that right there is close to 100 bucks.

[RedOctobyr]

Not the DS95, but I changed to 3 DS92A+, for $159. Not cheap, to me. My original KST were about $72. So added $87. But my KST almost caused 2 crashes.

A crash would have led to repair costs, and maybe replacing the clones anyhow with better ones.

I am only sharing my experiences and thought process, not trying to scare anyone off. I felt that the real ones were a good investment for me, based on my experience.

It's not just cost. If my KST had done their glitching during takeoff or landing, it could have hit me.

Sent using Tapatalk.

[sp00fman]

did you celectically insulate the underside of the electronics board? It seems it could touch the metal servo case.

[gothicbunny]

Red, did you add any insulation to prevent them from shorting inside the case? I'm just curious if anyone has had a glitch that has bothered to add a few pennies worth of electrical tape.

[RedOctobyr]

I have not actually done the insulation mod. It either didn't exist when I bought my iffy KST's (late July '12), or I just hadn't heard about it.

I don't know what the symptoms are of shorting servos? Mine had two symptoms.

The first was that they occasionally just wouldn't initialize. You'd power up, 2 would move, 1 wouldn't; and the 1 that didn't move acted unplugged (you could move it by hand). Power cycle the heli, and they'd usually all cooperate. This meant I checked every servo for movement before spooling up each time.

The second was that they started glitching. I had a big momentary jerk in flight one time. Landed, checked everything over, it was all fine. Then it happened again a few days later. Landed quickly, walked over, and saw one servo was actually jumping up and down (big swings). Took it home, it jumped around some more, then it smoothed out again. That was when I removed them, had ~20 flights. I might have tried the tape mod if I'd known about it But it was an intermittent problem that I couldn't reproduce. I was glad I got away with 2 things that *could* have been crashes, I didn't want to push my luck anyhow.

They never smoked, heated up, etc, to imply something disastrous. I have no idea what would cause the intermittent failure to initialize properly. I took the jumping to be a sign of bad pots? The replacement MKS servos (the only change I made) have been flawless, so it's not the FBL, etc.

But I still have one on my tail with 250+ flights that's doing great.

[sp00fman]

To me that sounds like some noise or dips on the powerline, perhaps caused by the servos itself, or one of them intermittently malfunctioning. The BEC on the ice-lite is not super strong as i read elsewhere. Could be a factor if it was temporarily overloaded during start-up.

I am running a big ~3300uF 6,3V capacitor on all my helicopters with a short lead to the FBL controller, or Rx on flybar (as that is the point where the power to the servos is split up to all the servos). That keeps most components happy. Also i plan to use the YEP45. It is a true 6A bec. I loaded it up with a carlight for 6A. Voltage dropped to 4,5V, as expected with the long thin servo lead on the ESC, but ESC was fine with it.

[gothicbunny]

Red, the symptoms you describe are exactly what one might see with an intermittent short.

Turnigy and KST could really just either add a little sticker to solve it or even just make the back piece of the servo case plastic. But for those that know to fix it themselves really do get an excellent and reliable servo at a huge savings.

[RedOctobyr]

Interesting, thanks for the info. I know I should open the KST I still have on my tail, and add the tape. It's an interesting thought if my problems could have been fixed with tape. Unfortunately, that fix either hadn't yet been discovered when I was dealing with this, or maybe I just didn't hear about it.

I'll confess I'm a bit unclear on how a short could be so intermittent to sometimes let them power up fine, and fail other times, with nothing wiggled/bumped/etc physically between attempts, and nothing burning up. But just because I don't understand something doesn't mean it's not true

Agreed that it could have been flaky power, at least for initializing problems. At the time, I was using an external Turnigy 3A/5A BEC. Cheap, I know. But it's worth noting that, even when I had 4 KST installed, my KST tail servo (from an earlier purchase, and which has continued to work well) never had a problem initializing, or jumped around. And after I went to the 3 MKS on cyclic (still a KST on the tail), I flew on that same Turnigy BEC for ~80 flights, no issues. And I now have ~175 on the Ice Lite, using its internal BEC with the 3 MKS & 1 KST. I haven't seen other things that make me think I have power problems.

[gothicbunny]

It is possible that the KST were just a little more power hungry than the MKS as well. I would be interested to see the CC logging comparing the two, but I doubt you want to be a guinea pig at this point. Glad to hear the one on your tail has been trouble free.

[RedOctobyr]

Yup, that's part of why I specified I went to the DS92A+, not the DS95, which likely draw a bit more juice. Though I'd assume that actual in-flight current would be more than the servos draw just powering up (eg- a pitch pump causing all 3 to swing hard at once). But I certainly don't know for sure

The Castle Ice logs unfortunately record nothing about the BEC output, either voltage or current. So I can't learn anything from that. And the vendor was very helpful, and took the 3 bad KST's back, so they're no longer available for testing or anything.

I'm not trying to start trouble about them or anything like that. Just sharing what happened to me, so people can make more-informed decisions. I honestly tried to give them a fair shake, and wanted them to work out (they're fast and inexpensive ), but once they started glitching in the air, then even on the ground, that was more than I wanted to deal with.

[PcChip]

Originally Posted by RedOctobyr

Agreed that it could have been flaky power, at least for initializing problems.

It's not flaky power, mine actually did that to me once too. It was just one servo and it was just one time, acted unplugged... I thought it was my BeastX clone at the time, now I see it wasn't. When I cycled the power it was perfect again though.

They've always been 100% perfect in-flight; the only glitching I've ever seen with them was due to flying with extreme vibes, and it was the FBL unit freaking out randomly - NOT the servos (I knew it had crazy vibes, but I test flew it anyway)

Despite that one strange non-power issue that ONE time, they've been perfect otherwise. All you have to do is just test your control surfaces before flying each pack, (which you should do anyway) and you won't have any issues