KDE 1750kV 450FX rewind for 12s

[rallyant]

Yeah it was hard, I almost gave up! am amazed people wind 100 of these a day in the factory! I decided winding motors was not for me half way through this wind.. I gave up been gentle on the last phase and just did what i had to and to my surprise no shorts... with any luck ill test it out today.

From my calcs, to get the equivalent cross section area for single strand (12s wind) would require around 0.6. I was very close to getting some 0.63 last night and giving up on the multi strand!
Patrick said multistrand was the only way to get this much copper into the motor as they did. so im guessing an 11T is not going to be possible with 0.63. finger's crossed a 10T will fit? im willing to bet the higher KV will more than make up for the reduction in wire.. and then perhaps a 5T double strand wind for a 6s comparison. Or a 0.88 (0.9 closest size?) for a single strand 6s wind.

My mate has a stock KDE so we can get a 6s vs 12s comparison now.
If mr mells HS calculator is correct we should see significantly less bogging

[rallyant]

Shes alive.
Test flight tomorrow if all goes well.

KDE 1750kV 450FX 12s rewind (0 min 20 sec)

[Jmann841]

Originally Posted by rallyant

Yeah it was hard, I almost gave up! am amazed people wind 100 of these a day in the factory! I decided winding motors was not for me half way through this wind.. I gave up been gentle on the last phase and just did what i had to and to my surprise no shorts... with any luck ill test it out today.

From my calcs, to get the equivalent cross section area for single strand (12s wind) would require around 0.6. I was very close to getting some 0.63 last night and giving up on the multi strand!
Patrick said multistrand was the only way to get this much copper into the motor as they did. so im guessing an 11T is not going to be possible with 0.63. finger's crossed a 10T will fit? im willing to bet the higher KV will more than make up for the reduction in wire.. and then perhaps a 5T double strand wind for a 6s comparison. Or a 0.88 (0.9 closest size?) for a single strand 6s wind.

My mate has a stock KDE so we can get a 6s vs 12s comparison now.
If mr mells HS calculator is correct we should see significantly less bogging

Very nice!

Changing KV should have little effect on the motors power itself so being a bit higher KV won't make any major difference other than having the advantage of a higher mechanical gearing reduction and possibly a bit lower resistance which can give you more power and efficency than if you had the extra turn. Just make sure you gear the heli properly.

If you have a Tach for your heli you can just run your 6s heli at 100% tjrottle and see what your HS is, then the same for your 12s motor, then adjust the gearing of the 12s to match the 6s.

Or you can use one of the many methods to test KV on a new wind and find out what the new KV is and gear off thT as well.

[rallyant]

Originally Posted by Jmann841

Very nice!

Changing KV should have no effect on the motors power itself so being a bit higher KV won't make any major difference other than having the advantage of a higher mechanical gearing reduction. Just make sure you hear the heli properly.

If you have a Tach for your heli you can just run your 6s heli at 100% tjrottle and see what your HS is, then the same for your 12s motor, then adjust the gearing of the 12s to match the 6s.

Or you can use one of the many methods to test KV on a new wind and find out what the new KV is and gear off thT as well.

Im yet to see an example of higher kV not producing more power in a given series of motor.
As we all know, power is force over distance over time, or in our case. Torque x RPM
so as long as the torque does not drop off greater than the multiplication of the extra RPM we will still end up with more power. Obviously this will up the amp draw and heat up the motor more along the way. Im not sure where the limit is, i assume winding or how much the torque of a motor drops off with a higher kV wind? as this is all brand new territory for me. From my VERY limited knowledge in this area, the calculations i have done seem to show the torque remaining almost the same in higher kV motors, this almost directly = more power. ie, 2000kv having close to double the power of a 1000kV

There is no mechanical advantage to gearing down a higher kV motor if the motor doesn't produce more power.
The advantage of gearing down higher kV is that they do produce more power. This is the reason i designed the Chase 360 with a 2 stage reduction.

examples in this size.
Xnova XTS 2618-1360kv 10P
Max Continuous Power(Watts) 720
Peak Continuous Power(Watts) (2 sec) 960
Max Continuous Current(Amps) 36

Xnova XTS 2618-1580kv 10P
Max Continuous Power(Watts) 800
Peak Continuous Power(Watts) (2 sec) 1060
Max Continuous Current(Amps) 40

Xnova XTS 2618-1860kv 10P
Max Continuous Power(Watts) 900
Peak Continuous Power(Watts) (2 sec) 1200
Max Continuous Current(Amps) 45


Scorpion HK-2520-1360KV Motor
Max Continuous Current 30 Amps
Max Continuous Power 630 Watts

Scorpion HK-2520-1580KV
Max Continuous Current 34 Amps
Max Continuous Power 715 Watts

Scorpion HK-2520-1880KV
Max Continuous Current 38 Amps
Max Continuous Power 800 Watts

[Jmann841]

I would love to see what the 6s KDE does on the dyno when you put a 7s battery in it as well. I would guess this will have the most power of all the setups.

It a 14s setup on the 12s motor.

[rallyant]

Yeah, I already started the hunt for a 14s esc for the job LOL.
But yes this thing was going to be insane on 7s! just a shame the motor and ESC didn't get along when i tried.
I think for all out grunt 7s and this motor with a castle ESC is where its at!
dont know of any other little 7s ESC?

be the perfect setup for the chase 380 stretch.
I did do some testing on wide chord (44mm) 385mm blades and it held up to that on 6s! so 7s should manage in the hands of a smack head on 380s no probs! I have some Zeal 380 prototype blades on the way for testing. so we will soon find out.

[Jmann841]

My guess for the higher power on higher KV is less resistance due to less turns. You can use thicker wire that is shorter, should decrease resistance a decent amount.

The torque is a function of the voltage and the resistance. If you keep the voltage the same and lower the resistance you increase the torque to match the higher RPM.

If using the same wire and winding with 1 less turn you have a shorter wire so less resistance. I think that is what you are seeing.

This is why increasing voltage without changing the winding gives you much more power. More voltage without a change in resistance.

But if you use exactly half as thick wire with exactly 2 times as many turns for 12s you should see the same power output as 6s just half the amps. Unless you're getting skin effect on 6s due to too thick of wire, but, I don't believe you will see that with such a small wire for a 450 motor.

[Jmann841]

Looks like KDS USA beat you to it. They just flew a 12s chase 360 at the OHB.

[Luvmyhelis]

Originally Posted by Jmann841

Looks like KDS USA beat you to it. They just flew a 12s chase 360 at the OHB.

I wouldn't doubt it. The Chase was being pushed by Glen right up front for a factory production 12s version. The entire idea of the dual stage was to be able to handle the higher rev 12s system. As it is just tough to get any of the newer gen motors to run 12s kv under an ave of 900. Even at 1020kv they are just packed! Especially with the 12 stator 10 mag motors I was playing with without increasing the mass of the can. In my own work and winding methods I preferred the Y for efficiency and also wound to every third stator with heavier single gauge using a custom wind Dan at Gobrushless has had superb luck with that he invented years ago. It is an amazingly complex wind. Prob was only one custom programmed Castle esc at this time was able to keep up with the phasing speeds the motor demanded to run at 100%. Virtually every esc I tried out of all the brands hit the wall at 56% or lower. Much easier with a standard 9 stator 6 mag can but they don't hit the torque I wanted to see in my own tests with them. I finally lost interest when none of the current 450 designs at the time were able to handle the motors until the Chase finally started evolving.

The ultimate test here will be to see the comparative Kde motors wound specifically for 6s and then 12s side by side in identical platforms and identical flight loads.

[Jmann841]

I spoke to Simon about it. It is a Savox 960(maybe 980, forget exactly, saw it earlier today)KV motor. He said the advantage is it draws very low amps when pushing it so everything stays cool. He said 20-30 amps which is exactly the watts our 6s motors is pulling except 40-60 amps. In the air, it looked no different than a well set up 6s either.

It's cool and always a benefit to lower amps, but, pretty much exactly what is to be expected.

He was using the castle 40hv ESC and had the castle guys here tune the settings. No issue with pushing it.

Have you tried a castle 40 yet? It definetly works.

[rallyant]

Those savox motors already run very cool due to a crazy big airgap. Unless Savox put the wrong stator in the 1900kv prototype I have. Back to back hard 3 minutes flights never get anywhere near as warm as the lipos do!
Seriously have never managed to get it above mildly warm even on hot days.
Id prefer the motor to run hotter. Make more power ans be more efficient.

Yes, after talking to Randy i pointed Simon to the castle for his setup. Took him a while to find one since castle stopped making them.. he was madly soldering up custom 12s pack last week that would fit in the chase.
Its a 12n10p
The kde is 8p but im still a little worried im reaching the limit of the hobbywings phasing ability. Ill upload another video.. if i let tje motor spool up to max rpm on the bench it blows a plug out. probably what it was doing om 7s?

Im concerned my 12

[rallyant]

I did this 3 times. No issues until i go max rpm. Then did this everytime.

KDE 1750kV 450FX 12s rewind (0 min 20 sec)

[Soccerjay]

Originally Posted by rallyant

Those savox motors already run very cool due to a crazy big airgap. Unless Savox put the wrong stator in the 1900kv prototype I have. Back to back hard 3 minutes flights never get anywhere near as warm as the lipos do!
Seriously have never managed to get it above mildly warm even on hot days.
Id prefer the motor to run hotter. Make more power ans be more efficient.

Yes, after talking to Randy i pointed Simon to the castle for his setup. Took him a while to find one since castle stopped making them.. he was madly soldering up custom 12s pack last week that would fit in the chase.
Its a 12n10p
The kde is 8p but im still a little worried im reaching the limit of the hobbywings phasing ability. Ill upload another video.. if i let tje motor spool up to max rpm on the bench it blows a plug out. probably what it was doing om 7s?

Im concerned my 12

What packs?

[rallyant]

Originally Posted by Soccerjay

What packs?

2x 850mha 6s packs

[Jmann841]

Haha you ain't kidding. The packs that Simon used looked like single cells he custom soldered together.

He had a few savox motors. I have the 5055-505kv and it runs very hot. I'm wondering if it's my ESC settings. I'll try to find the castle giys tomorrow if they are here.

Simon is a really cool guy! He said all his savox motors run cool, I wonder why mine is running so hot?

[rallyant]

I have a 12s 5755 520kV, 5765 550kV & a 14s 5765 430kV
Tke 5755 and 5765 have the same speck on the box. Not sure thats right. But the 5755 has small airgap and runs hot. Not scorpion hot. Just appropriately hot. The 12s 5765 has a big airgap and runs cool.
The 5765 14s has a small airgap again. No idea how hot this one runs yet. I might rewind one for 12s. Im sure it will outperform the 12s version. At the expense of running hotter. To hot is no good for belts.
I believe these are all still at prototype stage. So not sure what form they will be in when they hit the streets.

[Soccerjay]

Originally Posted by rallyant

2x 850mha 6s packs

Yah those don't look commercially available.....never heard of the company


Sent from my iPad using Tapatalk

[rallyant]

They are from the Australian Hyperion dealer. He has his own brand of lipos. Popular here for the glider comp guys.
They want the smallest lightest packs capable of plowing them as high as possible within the climb time. Soon find out how good they are in helicopters.

[Jmann841]

Originally Posted by rallyant

I have a 12s 5755 520kV, 5765 550kV & a 14s 5765 430kV
Tke 5755 and 5765 have the same speck on the box. Not sure thats right. But the 5755 has small airgap and runs hot. Not scorpion hot. Just appropriately hot. The 12s 5765 has a big airgap and runs cool.
The 5765 14s has a small airgap again. No idea how hot this one runs yet. I might rewind one for 12s. Im sure it will outperform the 12s version. At the expense of running hotter. To hot is no good for belts.
I believe these are all still at prototype stage. So not sure what form they will be in when they hit the streets.

Nice,

When you refer to the air gap, you are talking about the gap between the stator and the magnets correct? From my understanding, you want the smallest air gap possible between the stator and the magnets.

[Jmann841]

What is the max RPM that ESC can drive a motor on 50 volts? Looks like it may be a bit too much for that ESC?

Have you tested to see what your KV is? (Drill test or something?)