Koby 40 Success w/1.08?

[Seasick78]

Curious about any feedback that anyone can give who has had success with the Koby 40 with a Warp and Compass motor after upgrading FW to 1.08?

About to install mine as soon as my upgraded can arrives. A little gun-shy though... I bought this thing while walking around at IRCHA and had no idea that Koby's were problematic until after I got everything home.

Any positive experiences out there?

[kalleh]

Mine burned with 1.08. You can never know if its the same problem with only one data point though.


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[Seasick78]

Yeah I found the thread where you mentioned that. Hopefully I have better luck.

[Seasick78]

So far I have 11 flights on my Warp with the Koby and 1.08 with none of the issues mentioned previously. I am having a bit of a governing issue though... at 40% through 78% all is very well. As soon as I touch 79% or 80%+ the gov lets go and it surges up and down, even in a hover.

I have had a few issues with my stock motor and even the replacement can, so a Scorpion motor is on it's way and should arrive today or tomorrow. I spoke with Kontronik USA and they want me to see how the new motor does as well, otherwise, go up a tooth on the pinion. He said that I [should] be able to govern at 85% without this issue.

I have already reset to mode 1, then reprogrammed mode 4 and the result is the same. Hopefully the new motor will do the trick.

Other than that, I still have a clicking bearing somewhere. I think its the two radial bearings on the auto-hub. I ordered replacement bearings for those as well, and will change them out when they arrive on Saturday. They aren't affecting performance though, it just makes a very annoying clicking noise on every rotation. Masked in flight by the motor etc., but very noticeable on the ground when spooling down, or turned by hand.

This thing is flying VERY well between 40% and 78% though! Very smooth machine with very nice response. My BD3SX was dialed in after about 3 flights. Max current so far has been just shy of 20 amps, and the Koby's internal BEC is driving my MKS DS95's and 95i without skipping a beat.

Will update once the new motor comes in... Hopefully the gov issue is related to the stock motor somehow (?).

[Mr-Mike]

Hey Josh. I would be interested in seeing your tuned 3SX settings, only if its not too much trouble Sir -

Cheers!

[Seasick78]

So I installed the Scorpion motor. Soft start is better. Annoying noise is gone. Will need a few flights to compare flight times.

As to the governor issue I mentioned before... It's exactly the same. I reset via mode 1 again, and then mode 4 again. Flies great, just can't go past 78% without the gov losing its marbles.

Guess I'll just need to get a 17T pinion and see how that works. Just odd that it won't even go past 78% in a hover. Anyway... At 78% it governs extremely well so it's not really a complaint, just unusual.

[Seasick78]

Originally Posted by Mr-Mike

Hey Josh. I would be interested in seeing your tuned 3SX settings, only if its not too much trouble Sir -

Cheers!

Sure thing. Just keep in mind I am using FW 123 and not 200. Shouldn't be much difference between them though. Primarily elevator filter which is double in 200.

https://www.dropbox.com/s/wiv379ia00...%208-13-13.hcx

[Aeolus1]

Gonna copy too!

[Mr-Mike]

Thank you Josh! Seemed to load fine. I will do a deeper dive into your seeting for comparison - lucky me you are runing the same servos.

On the ESC, Kontronik specs the Koby can support 150K rpm for two poles which means 30K on the Scorp. @ 25 volts the Scorp is spinning about 15% faster - hmm. Not far off that 78% threshold. Maybe its going out of phase or something?

Good luck Josh and thanks again for sharing your settings!

[Seasick78]

Yeah... Just seems like I shouldn't have issues even up to 85% in a hover. Perhaps the gov would let go with a load due to lack of overhead... But in a hover just doesn't seem to make sense.

I got another 3 flights in early this morning, and I can now verify that the Scorpion motor sucks away about 1.5 minutes of flight time vs the stock motor. It runs very well though, and 5 minutes is still good at 2950 rpm so that's certainly fine by me.

One last change today on my BD3SX setup... I did lower the gain 3 more points to a flat 40% and I'm pretty sure its there to stay.

[Mr-Mike]

Thanks for the additional 3SX setting feedback! Also interesting, your flight time differences.

I hope you find a comfort zone with the Koby. I am sure many will be interested. You could take it out of gov and try to fly an 85% throttle curve (line) instead. The Jive (so I am guessing the Koby) automatically sets pwm and timing to optimal so there really is no way to 'fine tune'. As you said, a larger main pulley may be an option to get the headspeed down but I have been told that you ideally want to fly in the motors most efficient RPM range.

Good luck!

[Seasick78]

You're welcome, Mike.

I'm actually aiming for a slightly higher idle 2, is all. Not a lower head speed.

If the motor/ESC combo is at its limit, then the pinion change should help make up the difference.

From the performance side of things all has been very good. Pulled a 30 amp peak spike today, but is typically down in the low teens.

So far, so good!

[Bob O]

A 17T pinion would definitely get you closer or right where you want to be.

[Mr-Mike]

Originally Posted by Seasick78

You're welcome, Mike.

I'm actually aiming for a slightly higher idle 2, is all. Not a lower head speed.

If the motor/ESC combo is at its limit, then the pinion change should help make up the difference.

From the performance side of things all has been very good. Pulled a 30 amp peak spike today, but is typically down in the low teens.

So far, so good!

I'm sorry, I meant the 'get the motor speed down'.

For what its worth I spoke to Kontronik and they measured the Jive @ 215K rpm (2 pole) with a well matched motor (I am guessing they tested with a Pyro). Anyway, that works out to close to 10K rpm more than the Scorp max spec. I am not sure if that applies to the Koby - I only asked about the Jive I would guess it does though.

[Seasick78]

I am told that the functionality of the Koby is similar to the Kosmik and not the Jive... Not sure how different, but 85% is the recommended max.

Having said that, I think there is merit to your point about the 30,000 rpm. But... The spec sheet says greater than 150,000 with 2 pole, not "max," no?

1360kv motor at peak voltage would be at 34000. Even at 22 volts it would sit right at 30,000'ish.

What would be great would be if someone else currently running a Koby could change their experiment between 80% and 85% and see if they get the same result. I have had the same result no matter if the stock motor or the Scorpion 2520-1360.

Any takers?

[Bob O]

I have a replacement Koby 40LV that I would love to use, but sadly it's still in the box as I don't want to risk having it burn again.

[Seasick78]

Originally Posted by Bob O

I have a replacement Koby 40LV that I would love to use, but sadly it's still in the box as I don't want to risk having it burn again.

Have you verified that it has 1.08? Mine came spankin new, with 1.06. I'm not concerned about any sort of burn-up issue... I'm just trying to get a conclusive answer on this governor issue.

Aside from that question, mine is performing extremely well.

[Wh1teAfr1can]

have you updated it to 1.08? that was update to fix issues with this motor.

[Seasick78]

Originally Posted by Wh1teAfr1can

have you updated it to 1.08? that was update to fix issues with this motor.

I sure did. As previously stated, I checked and updated before I ever installed it on the model. Mine came new with FW 1.06 and I upgraded to 1.08.

Two motors, same issue at the same throttle output. Have also reset to mode 1 then re-programmed mode 4 (twice)... Same result above 78%.

[Mr-Mike]

Originally Posted by Seasick78

The spec sheet says greater than 150,000 with 2 pole, not "max," no?

1360kv motor at peak voltage would be at 34000. Even at 22 volts it would sit right at 30,000'ish.

True Josh but not having any indication of what "max" is, I tend to go with the safest option. Having said that, I also learned from Kno that the Jive is also spec'd at 150K and tested at 215K That's 70% higher! If the Koby comes anywhere close (and it should) than you should not have a problem (like you suggest).