Kosmik vs Jive

[HeliAficionado]

I have used both the jive 120 and the kosmik 160 on my compass 7hv to get two completely different outcomes. I am trying to get 2150 head speed with the compass v2 motor. With the kosmik, 14t pinion, I am at 93% throttle. Same set up, with jive, 12t pinion at 85% throttle. Does this seem right?

[Wh1teAfr1can]

Originally Posted by jwalk77

I have used both the jive 120 and the kosmik 160 on my compass 7hv to get two completely different outcomes. I am trying to get 2150 head speed with the compass v2 motor. With the kosmik, 14t pinion, I am at 93% throttle. Same set up, with jive, 12t pinion at 85% throttle. Does this seem right?

The 85% on the jive sounds right as in the numbers look correct but you are way over the acceptable level for governing. you should not be over 65% throttle on the Jive or 80% throttle on the kosmik. 60% on the jive will give you the same headspeed as 80% on a kosmik. now this is assuming that your throttle end points are unchanged (100/100). for the headspeed you are looking for you need to be on a 14t pinion for both.

65% on Jive gives you 2150 on 14t
and 82.5% on Kosmik will give you the same on 14t

you dont want to go over 65% on the jive and around 80% on kosmik is the sweet spot.

[Mercuriell]

Originally Posted by jwalk77

I have used both the jive 120 and the kosmik 160 on my compass 7hv to get two completely different outcomes. I am trying to get 2150 head speed with the compass v2 motor. With the kosmik, 14t pinion, I am at 93% throttle. Same set up, with jive, 12t pinion at 85% throttle. Does this seem right?

Not really. Jive endpoints ate around 93%, unless you calibrate it to your Rc using endpoints. This means that you get 100% throttle on the Jive at a lower point than on the Kosmik. Not sure why you have such a vraiance in pinion size. Mr Mels calculator reckons you need 15t pinion for that HS on both Kosmik and Jive!

[HeliAficionado]

Thanks for your responses. I just wanted to check, if there was a big difference between the two esc's and it looks like about 15% throttle.

[Wh1teAfr1can]

It is in the way the 2 controllers handle PWM input. I did a write up on here about it:

http://hf.rob.com/showthread.php?t=480502

has to do with the Jive using a formula PWM = 50% + throttle %/2
while the Kosmik PWM = Throttle %

[Heli G]

Related to this topic, is there any difference in the way that the Jive and Kosmik handles commutation, more specifically in the way it manages auto timing?

[Stolla]

Originally Posted by Wh1teAfr1can

It is in the way the 2 controllers handle PWM input. I did a write up on here about it:

http://hf.rob.com/showthread.php?t=480502

has to do with the Jive using a formula PWM = 50% + throttle %/2
while the Kosmik PWM = Throttle %

I dont know if i dont understand what youre saying or you are referring to something different but there is a difference between thr percentage and pwm on kosmik, pwm can vary considerably on the same thr percentage as its dependedant on load, i.e motor opening.
If you look at the graph on kosmik i added the thr percentage and the pwm values for reference, According to this thr % does not equal pwm, neither can you attach a fixed thr percntage value to a constantly changing pwm
pdf shows better detail

[Wh1teAfr1can]

Originally Posted by Stolla

I dont know if i dont understand what youre saying or you are referring to something different but there is a difference between thr percentage and pwm on kosmik, pwm can vary considerably on the same thr percentage as its dependedant on load, i.e motor opening.
If you look at the graph on kosmik i added the thr percentage and the pwm values for reference, According to this thr % does not equal pwm, neither can you attach a fixed thr percntage value to a constantly changing pwm
pdf shows better detail

It is only on the initial start up before it goes into closed loop mode. its the reason that if you load up the head too much you can actually (in mode 4) lower the headspeed that it will govern at because 80% plus load is not the same as 80% unloaded.

[Stolla]

Off course 80% plus load is not the same as unloaded but still pwm and thr percentage are two totally different things, one being the controller opening the other the motor opening, so still i dont get what youre trying to say by one equals the other, its a very confusing statement espescially for people trying to understand pwm values which us a crucial part of a well governed setup.
For a constant thr percentage Pwm values change, i.e goes higher with load so there is no exact formula as its motor and load dependant
If you are trying to say jive will at a lower percentage reach 100% pwm than kosmik you are correct but saying one equals the other will have people think they can set thr percentage at 99% to keep pwm under 100%, that as you know is incorrect.

[Wh1teAfr1can]

Originally Posted by Stolla

Off course 80% plus load is not the same as unloaded but still pwm and thr percentage are two totally different things, one being the controller opening the other the motor opening, so still i dont get what youre trying to say by one equals the other, its a very confusing statement espescially for people trying to understand pwm values which us a crucial part of a well governed setup.
For a constant thr percentage Pwm values change, i.e goes higher with load so there is no exact formula as its motor and load dependant
If you are trying to say jive will at a lower percentage reach 100% pwm than kosmik you are correct but saying one equals the other will have people think they can set thr percentage at 99% to keep pwm under 100%, that as you know is incorrect.

I know that it changes under load it is simply for the start of the flight where the initial headspeed is calculated so the controller sets the output at 80 calculates the motor speed then uses overhead to keep it at that the whole flight. the 2 controllers just use a different formula for calculating that initial value. then when you change flight modes during flight it scales the head speed accordingly.

The key take away is that the initial throttle to pwm relation used is calculated differently for the jive vs the kosmik.

[Mercuriell]

Can you guys explain the differece between throttle input and throttle effectve please?

[Wh1teAfr1can]

Originally Posted by Mercuriell

Can you guys explain the differece between throttle input and throttle effectve please?

Basically when you put in a throttle percentage for either jive or kosmik this is the starting pwm. so say you are feeding the controller 80% pwm which for kosmik is 80% throttle and for the jive its 60% throttle due to the formula of 50% + throttle% /2.

that 80% PWM is taken and the controller runs the motor up to stationary 80% PWM depending on the load this can vary the rpm slightly this is why it is suggested to let the transition between start up and going into govenor mode be done with the heli at zero pitch. the controller then records the rpm that was achieved and then swaps into closed loop mode. Now the pwm is completely controlled by the esc. the throttle percentage you are feeding it now becomes a point on a sliding rpm scale that was generated by that initial start up. that is why its possible to change head speeds during flight without the pwm calculation again.

Hope this helps!

[dl7uae]

Tbh that naming is my "invention".

Tbh again: I had done on the fly and without much thought.


"Imot integrated": Kontronik calls it now (in a log file) "Battery Current". (Ahh, that's why it looks integrated!)

"Imot": Called "Motor Current" in a log file (header). (Okay, that fits.)

"throttle input": Harald (Kontronik) calls it "Geber". Hmm.. "Geber" means "encoder".

"throttle effective": Same word for it in the header: "Geber".

"effective timing": They call it "Tv" in the log file header.

Well... no idea..
Kontronik had asked if they can use the files from the JLog page. There were no comments, no protests about the naming of the items.

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And to the original question: My idea was that with an agreed throttle value for bailout the effective throttle for the ESC is different (shift) from that in the input. But I never tested it practically. I have only a few days a KOSMIK now - but have not been using it.

[swalko]

Throttle input - throttle value from radio

Throttle effective - throttle value "going to motor"

Cases:

1.) Hold: Throttle input 0 , Throttle effective 0

2.) Idle: Throttle input 75 , Throttle effective 75

3.) Bailout: Throttle input 30 , Throttle effective 0

[dl7uae]

1.) Hold: Throttle input 0 , Throttle effective 0

2.) Idle: Throttle input 75 , Throttle effective 75

3.) Bailout: Throttle input 30 , Throttle effective 0

Okay, thanks, then my assumption was correct.

"Throttle to motor": That is "PWM", but I know what you meant.

Thx a lot, swalko!

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Btw: "Tv" vs. "timing effective": I think "Tv" means "Timing Vorlauf" --> "Vorzündung" == "preignition" (advanced ignition). So "effective timing" should be correct also.