Kora 15-12 and 5S

[Rush]

I ended up ordering the Hacker A30-10XL 900 KV motor. was cheaper than the kora 15-12. I'm gonna run that on 24T. I should have the heli together by the end of next week so i'll see how it flys with temps and amps used by the end of the weekend. I'll run it on a CC60. Hopefully it does well on a 24T. But with the motor in the midband range on 14.8V, i'm just not to sure of that. On 5S it should be very interesting but my cellpro wont handle 5S. I'd need a new charger...

... I'm a plant engineer, but never was interested enought in electric motors. But we run those things almost always at their 95% limits. They run hot, but they're built for it. How come in heli applications, and particularly in this case, we run our motors at midrange? Why not higher?

All i need now is that 4S Tp/PQ adaptor....

[Jafa]

No - I think most people with a hot electric setup do have good temperature
I just like the performance of the 15-12 with very little temperature
Don't have to worry about anything getting toasted

The only problem with the A30-10XL is that it's rated at 32 amps for 30 seconds
It has the lowest amp rating of all the motors I've looked at
My Lepton is sinking 21 to 24 amps in the hover

[Rush]

It is?.. but lepton owners seem to run it w/o it burning up on them as i've yet to see a post of one. Besides, save me 50 USD which i can use for a good 4250 4S FP lipo hehehe

This motor KV and Current pull thing is a mystery to me. How can motors pull 76A in a tic toc, that are rated way below that draw? So there's something there that i'm missing. All the motors i've looked at aren't any really much different in terms of 600W power.

So 600W power, 14.8V Lipos, the only difference is the manner in whch amp ratings are taken. And at what rpm does the motor become the most efficient?

I'll read up on it again. maybe i'll come up with a way to justify it.

[cybinary]

Rush, I was looking at that one as well but if I can't get a hyperion that will support 5S I think I will get the Hacker A30-12XL since it has a high enough rating for the amps we will be putting through it with 5S.

BTW: I also have the cellpros and think their great chargers. They just annouced their new 10S charger that will allow you to charge duel 5S 5000Mah packs at the same time. =)

[Rush]

I dont really want to buy another charger at the moment i've gone through 3 already. aint exactly cheap and the investment in Lipos' is another thing..... haha Love my cellpro. I just hate that they have to have that proprietary connector of theirs and not the more common TP/FP/PQ ones. hehehe they shoud give that for free.

I think the A30-10Xl will work on 5S. Its actually more suited for 5S work due to the higher amp rating vs the A30-12Xl. It seems opposite to logic.. but there's something there i'm missing on why lower KV motors seem to be partnered with higher V lipos.

mabe someone will post on why that's so.

[cybinary]

I will look over the A30-10XI, I looked at the A30-10XL and it didn't seem like it would work. Don't remember why...

I know what you mean about chargers, seems like I just bought those duel Cellpros less than a year ago and here I am upgrading again... Hopefully this new 10S will be enough charger that it SHOULD cover all my charging needs for now and the future.

[Rush]

I want a X9303 before i even think of another charger.. hehe

[Jafa]

Remember that the 76 amp peaks are just that - very short duration peaks

[cybinary]

And a very nice radio it is Rush, let me assure you in that!!!

[Jafa]

And at what rpm does the motor become the most efficient?

That's the magic question - why don't the manufacturers tell us? It would make life easier

I'm now seriously considering trying 5S 3300 with the Kora 15-12

[rotodingo]

Jafa, that's what i'm doing for some time now. With 18T pinion and 74% on the Jazz i got 2700 rpm.

Rush, you will need a smaller pinion. 24T is too much to make a good use of the Hacker.

Nicolas

[Rush]

Nicolas,

why? the 24T does get hot on 24T though. I have around 2900 at 100% TCV. I only use 2700(~90%) to 2800(~95%) rpm though as any more than 2800 i get tail vibes which can be quite pronounced. But 85% allow me to use the governor mode with some headroom left. I also run high timing on the Hacker.

Whats the benefit of going to 23T?

I'm still on fixed endpoints at the moment as i cant get the gyro setting right.

My main problem with the Lepton now is i cant get the gyro/rudder combo to click. I'm using a G500T and a DS3400G servo. The ball link on the rudder is at the innermost hole of the servo arm in order to get as much travel on the limit pot. That being the case, if i back down gain to just the point it wont wag in flight, the tail drifts and i lose the tail during hard collective maneuvers (tic tocs, 3D). This is on a DX7.

If i raise it any higher, it'll hover fine and for stable forward flight, but as soon as test hold by shaking the tail left and right, it starts to wag. On sudded stops with the right rudder, the tail bounces as soon as you stop rudder input. Sorta bounces.

i have no idea what to do with it.

[rotodingo]

The A30-10XL is supposed to be the good choice on 4S with 23T (like with the hyperion). So with 5S the HS you have are strange...

Anyway only the results you have are the clues to decide if it's good or not.
My Lepton is also vibrating above 2800rpm. Not all the time, just sometimes... So i stay at 2700 and everything's fine.

Nicolas

[Rush]

Hi Nicolas, I'm only using 4S. The power on 4S is very good already and it zips around faster than a 450. The T500 guys are amazed at what it can do on 4S whereas they need 5S-6S to get the same performance.

On 24T, 4S gives 85% TCV of 2700 rpm which is good enough for 3D maneuvers given how quick/responsive cyclic and collective is on this heli... I dont believe you need torun higher than that. No bogging on a 95-x-87.5-x-95 Idle 1 curve. PCV is linear 0-100

The only reason i'd run 23T is to get the motor temp lower... it is very hot after a 5-10(scale flying) minute run. But it will bring the headspeeds down so i am still thinking if i go to 23T. It will allow me to run higher TCV thoughs. What motor temp are you getting on your motors? The A30-10XL is hot... I may try 23T this weekend just to compare.

[gary mullen]

rush I've the same motor a30 10xl and cc60 75% 24t and I'm worried about the motor heat. I've ordered the hacker cooling fan.but let us know how the 23t grear works for you.

[Rush]

Hi Gary... ok. I have the fan on the hacker already. doesnt seem to help much as it is. What timing do youhave your motor on? i'm on high timing as i read in a post here the for low KV motors, its better to have the timing on high.

[prototype3a]

Originally Posted by Rush

My main problem with the Lepton now is i cant get the gyro/rudder combo to click. I'm using a G500T and a DS3400G servo. The ball link on the rudder is at the innermost hole of the servo arm in order to get as much travel on the limit pot. That being the case, if i back down gain to just the point it wont wag in flight, the tail drifts and i lose the tail during hard collective maneuvers (tic tocs, 3D). This is on a DX7.

If i raise it any higher, it'll hover fine and for stable forward flight, but as soon as test hold by shaking the tail left and right, it starts to wag. On sudden stops with the right rudder, the tail bounces as soon as you stop rudder input. Sorta bounces.

i have no idea what to do with it.

Sounds to me like the tail servo isn't moving the tail fast enough. Basicly the servo isn't able to move the pitch of the tail blades to where the gyro wants them quickly enough so it is causing the servo to overshoot. Try moving the ball on the servo horn out one hole. Then readjust everything and try it all again. I'd bet that it will perform much better.

[rotodingo]

Rush, my Kora is very good about heat. Now with 5S motor temp is even lower. The integrated fan is vry efficient.

Nicolas

[Rush]

Prototype,

I've tried the 3400G on inner, middle and outer holes already of its servo arm. Tail control from the 3400G just isnt ideal... its either to loose or to much with a 1 pt cvhange in the gain value.

I switched it out with my 401. I'll try it with that. Let you guys know if it performs better this weekend.

[Blades_Cuts]

I've tried 3400g with 401. I never could get rid of the tail wagging on piruette stop. And the tail kicks when punching out. 9650 with 9257 gear set mod worked better for me, combined with home made CF tail control rod and chinese weight mod.... I posted pictures and video link on the other site.......

http://www.runryder.com/helicopter/t402043p1/