Koby 40 fluctuating over 78%

[Seasick78]

I've been chasing this down in the Warp forum and asked a few questions in a thread in this forum, but am creating a separate topic here with hopes of drilling down on the answer.

I have my Warp 360 equipped with the stock 16T pinion, Koby 40 with 1.08 (verified), mode 4 programmed, and 3 throttle settings (60%, 67.5%, and 78%). Motor is a Scorpion 2520-1360 on new 6S 1300mah packs.

Lets just forget about headspeed because that isn't what my question is. The issue (unless its normal?) is that if I set my throttle curve above 78% the rpm begins to fluctuate up and down as if the gov is hunting. I'd think this is fine if I was governed at the max limit, but this happens while in a hover and several people have suggested the Koby should be able to govern up to 85%.

I have no idea... If this is normal, that's fine by me. I'm just trying to verify one way or the other. I was asked in another thread to make a little video of this. I'll try to do that soon but likely won't get anymore flying in until mid next week due to travel (maybe Sunday afternoon, but not sure if I'll have time).

Even without a video though, all I am saying is that if I set 79% or higher, the rpm slowly surges. It's not drastic. But it is very obvious, and the tail kicks in conjunction with the rpm fluctuations. It's as though the gov is hunting, but usually I have only had 'hunting' gov issues when under a load, not just in a hover.

As I said, this may be perfectly normal for these ESC's. If so, I'm perfectly okay with that. The gov is very nice between 60% and 79%, and my max rpm at 79% is perfectly acceptable for the pinion I have installed.

Btw - I've had the exact same result after switching between the stock Compass motor and this Scorpion motor. I'm not getting any blinking lights upon shut down, and have reset to mode 1 then back to 4 around 4 times.

Normal? An issue? Suggestions?

[Seasick78]

Ok so I was able to grab a quick vid right before I left the house. Here at you might be able to see the tail kick better and hear the rpm fluctuating. The vid doesn't capture it very well IMO. If anyone was standing right next to me it is very very obvious. I bumped it up to 81%, then back down to below 78%.

[ame]http://youtu.be/4D94Ag2MQcU[/ame]

[Wh1teAfr1can]

what battery are you using? how free is the drive train? is the motor and or battery excessively hot after hovering it?

[Seasick78]

Originally Posted by Wh1teAfr1can

what battery are you using? how free is the drive train? is the motor and or battery excessively hot after hovering it?

1300 mAh, 35C, 6S, PunchRC Platinums. Drive train is very good. No excessive drag nor slop. Motor is warm after a flight but never 'hot.' Batteries are barely even warm. Half of the time I can't even notice any additional heat warmth on the batts at all.

Altogether everything is running very well. Just this thing over 78%.

[jamin_00]

Hey Josh, thanks for posting the vid.

This looks like not quite flat throttle curves. Maybe you have accidentally got 1 point on the curve not the same. Do you have a hover trim for throttle, ont he 14sg I have 2 dials, 1 for pitch and 1 for throttle, maybe its this. I always deactivate them.

What radio is it on??

[Seasick78]

I am using a Jeti DS-16 and the curve is set to constant. In this radio you can set a 3 point, 5 point, 7 point, 9 point, V, offset, positive, negative... Whatever... But when it's set to 'constant' it is nothing but a flat line and all you do is select the value.

In flight I am able to adjust that flat line wherever I want. I have set it to 80% before powering up, same issue in flight. Or, I can set it to 78% and its fine, then slowly raise it in flight... As soon as it gets to 79%-80% it does the fluctuating.

Bottom line - with the setting I have programmed, 'flat' is the only possibility.

[Seasick78]

No other suggestions from anyone from Kontronik? Hmmm?

[jamin_00]

Sorry, real life been busy tonight

Your not trolling are you with that comment???


Have you tried with a throttle curve at 79% or higher before ESC initialisation and not adjusting your throttle curve during the flight. If I understand it right, you dont have to flick to idle 1 for example, you can just adjust the curve during flight?

[Seasick78]

Yes I have had the curve above 79% prior to initialization as well as during flight basically any way if getting there, I've tried it.

I 'can' adjust it in flight, but typically have it set to idle 2.

[jamin_00]

Do you have a progdisc?

I have never used the Koby line before but you should be able to reduce the gain of the gov,

[Seasick78]

No. But I borrowed one prior to installation for the purpose of verifying the FW version. It had 1.06. We got 1.08 loaded on it then reprogrammed the ESC.

** Edit - we ensured the prog disc had the latest version as well.

[jamin_00]

OK, let me ask some questions on the Koby as this is not my area and I will come back to you. I would reduce the gov gain in the mean time and see how this fares.

[Seasick78]

Wish I could. The prog disc I borrowed is an hour and a half away.

I don't "need" 80%, I'm just curious why it won't go there based off everything I have read.

[jamin_00]

Im tempted to still say it something to do with the radio curve.

I know with the DX9 MKII for example, you can click 3 times on a single % value in the throttle curve as you edit it so this does not give a true straight line if that makes sense to you. I have not seen or heard this issue before, have you?

It can run up to 100% and it will not pulse like that, it just wont govern so it will over speed etc but again, it will not pulse like that.
It really does point to the radio curve.

[Seasick78]

I'll make a video so you can see what I mean about the 'constant' value of the DS-16. When selected, there is no possibility of anything other than a flat line. There is one value to adjust and it moves the entire flat bar up or down.

[Seasick78]

http://www.youtube.com/watch?v=80f1xx_nqh0

[jamin_00]

Hey Josh, sorry for the delay but I just got off the phone with the factory. This is a strange one and not an issue that they have a resolution for immediately.

Have you just changed radios at all? I ask because your HC vids are with a Futaba. If you have has this issue only been present since then or before? Has it been there all the time since you have had the Koby or not?

They will be looking at the info and I may need more from you if thats ok but as soon as they have any questions or info for you I will let you know asap.

[Seasick78]

Originally Posted by jamin_00

Hey Josh, sorry for the delay but I just got off the phone with the factory. This is a strange one and not an issue that they have a resolution for immediately.

Have you just changed radios at all? I ask because your HC vids are with a Futaba. If you have has this issue only been present since then or before? Has it been there all the time since you have had the Koby or not?

They will be looking at the info and I may need more from you if thats ok but as soon as they have any questions or info for you I will let you know asap.

Thanks for looking into this. I did recently change radios but I've never used the Koby with anything other than the Jeti radio. Also, I have no issues whatsoever with any of my other ESC's. Again, this may not be an "issue" either. It just seems like it shouldn't be that way so I wanted to ask.

[taosgraveyard]

I am having just about exactly the same issue on the bench with a koby 40 amp and a scorpion 2221 1630 KV.

Also using a Jeti radio, none of my other ESCs ( jive, helijive, kosmic, YGE) have this problem. If I set the flat throttle curve to 78.5 percent percent it stops


But at 79 it does it.

Manual says to run minimum throttle at 80 when in mode 4, and I would sure like too, because I want a little more Headspeed.


I do have a Progdisk so I will try turning down the governor gain, and post when I finish with that experiment

[Seasick78]

I recently purchased a prog disc. Looking forward to your results. If it works ill follow suit.