Originally Posted by Border Lord

Hi Pitchp

Thanks for that. Calculator says 1700Kv on standard main gear (150t) and 11t pinion gives 2952 at mid flight.
https://www.hobbyking.com/hobbyking/s...00KV_930W.html
Looks like the plan is starting to come together.

BTW, when you say 2900 to 3000, are you referring to flat out h/s?
Calculator says 'hover rpm'. not quite sure what that means.
Surely hover rpm is dependent on throttle curve.

Thanks

BL

That does not sound right. Typical kV for a 450 on 3S with 11 tooth would be ~3500.

Pat MacKenzie

edit -oops . Should have followed the link to your battery. For 6S then 1700 would be about right.
But this is one of those HV versus LV things. Your battery weight is a bit higher than a 3S 2200, motor is the same weight but your ESC will end up being larger.
3S would be simpler

He's looking at a possible 6s set up Pat, if I read his post correctly.

Originally Posted by Paul 1968

He's looking at a possible 6s set up Pat, if I read his post correctly.

See my edit above

Originally Posted by Border Lord

Hi Pitchp

Thanks for that. Calculator says 1700Kv on standard main gear (150t) and 11t pinion gives 2952 at mid flight.
https://www.hobbyking.com/hobbyking/s...00KV_930W.html
Looks like the plan is starting to come together.

BTW, when you say 2900 to 3000, are you referring to flat out h/s?
Calculator says 'hover rpm'. not quite sure what that means.
Surely hover rpm is dependent on throttle curve.

Thanks

BL

that's a 6s motor! do you want a 6S setup or a 3S?

Originally Posted by pmackenzie

.....your ESC will end up being larger.....

Depending on current ESC (if it's a 3 s-6s) he could keep using it. The bec could get a bit hotter having to cut 22v down to 5/6v, but the speed control would run cooler. Twice the volts = half the amps. Right?

~psguardian

Originally Posted by psguardian

Depending on current ESC (if it's a 3 s-6s) he could keep using it. The bec could get a bit hotter having to cut 22v down to 5/6v, but the speed control would run cooler. Twice the volts = half the amps. Right?

~psguardian

Sort of.
If you can stay with the same ESC, then it would have lower loss due to I^2R, but switching losses will be higher. How that works out would be interesting.
But if you switch to an HV esc then it will almost certainly have a bigger Ir and the losses will end up about the same. (Ever notice that HV ESCs almost always have heat sinks)

Motor losses will be the same because to half the Kv they have to use twice as many winds and half the wire cross section. So no change in heat there.

Ditto for the battery.



Pat MacKenzie

Paul 1968

Spot on. I did mention in my post that I was going for 6s

Two things that appeal to a tinkerer like me are a stretched 450 on 350mm blades, and a 6s set up.

My 450 Ver2 has a Plush 40a esc, which is 6s capable, but I like the look of those YEP 45a ones.
They have a 6a bec, so that should run cooler.
With a 6s setup, I do not need 45a, but I like the insurance of a heavier bec.
Overall weight is not a real priority. looking for a floaty type model for those calm summer evenings (remember those?)
Agree Pat, 3s would be simpler, but I already have two 450's running 3s, and I want to try something different.

Thanks all

BL

Since you already have 3S setups it would be very interesting to see how your 6S setup compares.
To be fair you should try to get similar motor size and total battery weight.


If you want "floaty" then shoot for 2600 to 2700 HS. Much easier on the mechanics and calmer.

Pat MacKenzie

Originally Posted by Border Lord

Paul 1968

Spot on. I did mention in my post that I was going for 6s

My 450 Ver2 has a Plush 40a esc, which is 6s capable, but I like the look of those YEP 45a ones.
They have a 6a bec, so that should run cooler.
With a 6s setup, I do not need 45a, but I like the insurance of a heavier bec.
Overall weight is not a real priority. looking for a floaty type model for those calm summer evenings (remember those?)
Agree Pat, 3s would be simpler, but I already have two 450's running 3s, and I want to try something different.

Thanks all

BL

I'll let you know on the YEP 45 amp esc, I have one on the way for my HK450Pro TT FBL along with its programming card.

Edit: After a previous post with Pat Mackenzie I'm considering the 120 amp version too for my HK600 MD500 too. It's supposed to have a great soft start and a useable governor too.

Originally Posted by Atomic Skull

http://www.youtube.com/watch?v=AjG0jX5NuZ0

The only place I disagree with this guy is about tightening the feathering shaft bolts. You should be able to tighten them up without binding or grittiness/notchyness. A slight bit of drag is ok as long as they turn smoothly. Leaving the bolts loose and relying on locktite is asking for trouble, especially with a flybarless head. I was able to tighten mine up completely with 1 shim on either side with only a slight bit of drag and totally smooth turning grips.

Don't use the collars provided with the kit, use the 1mm ones that come with the Pro feathering shafts.

Hey A/S, I'm hurt! When in the vid do I advocate leaving the bolts loose? I agree with you it's bad practice and dangerous!

Simon

Hi Pat

Yes, you're right, but since I am going for a stretched boom and longer blades as well, not sure any comparison would be meaningful.
As far as weights are concerned:

lipo 3s 215g
6s 180g

esc 3s 79g
6s 105g

motor 3s 101g
6s 96g

Total 3s 395
6s 381

6s setup is lighter!

Actually, these are based on published weights, so may not be entirely correct, but since going to 360 blades gives me about 12% bigger rotor disc area, don't think that will be a problem.

Pat
Take your point about losses in the esc, but I am in fact not going for HV.
Both the esc I linked to are 6s capable, which I don't think is considered HV these days.
Consider a 45a capable esc with only, say, 15a going through it. Doubt if it would even need a heatsink.
Also, I believe the Plush has a linear 3a bec, where the YEP has a 6a switching.
There's less losses right there.
Agree about 2600 to 2700 h/s for a 'floaty' model.
Pitchp has suggested 2900 to 3000 at WOT, so we are in the ballpark.
The H/S calculator he linked me to suggests 1700 Kv will give me 2900 or so, but it refers to this as 'hovering' throttle. Not sure quite what this means.
Having said that, that is with an 11t pinion, so if my h/s is too low, plenty more to choose from.
If it's too high, there's always the throttle curves.

Cheers

BL

Originally Posted by VelocityRC

Hey Atomic Skull. Do you have a link where I can get some of those 2x3.6x0.2 steel washers ??

Bill S.

Been trying to find them myself, nobody sells them separately that I have found. I always save any extras I have. Tarot sells a washer kit that has 2 of every washer but the 2x3.6x0.2's are copper not steel (Value hobby carries it). They still work but the arms will have a bit of drag. On most parts the copper work as well as the steel but not here for some reason.

Some people seem to have gotten the washers with the head, but mine did not include any.

The Robird G31 has an adjustment for leveling the swash at min/max collective that is only accessible on the gyro itself, not the setup program. The setup program only has an adjustment screen for subtrim at the middle of the collective. Be aware that if you do this then it will overwrite the subtrims you've already set up. However if you've already set subtrims and the servo to swash link lengths you can easily fix any screw ups by zeroing the subtrims in the setup program then disconnecting the gyro and going through the swash leveling again. Seems weird that this is on the gyro but not in the setup program. I was wondering how the gyro was supposed to know about unequal travels.

Originally Posted by sgbfly

Hey A/S, I'm hurt! When in the vid do I advocate leaving the bolts loose? I agree with you it's bad practice and dangerous!

Simon

Oops sorry. I could have sworn it said you should back off on the bolts a little if you get binding but I guess that must have been another video. I watched so many videos on helicopters they all startd to blur together I guess.

Originally Posted by Border Lord

Paul 1968

Spot on. I did mention in my post that I was going for 6s

My 450 Ver2 has a Plush 40a esc, which is 6s capable, but I like the look of those YEP 45a ones.
They have a 6a bec, so that should run cooler.
With a 6s setup, I do not need 45a, but I like the insurance of a heavier bec.
Overall weight is not a real priority. looking for a floaty type model for those calm summer evenings (remember those?)
Agree Pat, 3s would be simpler, but I already have two 450's running 3s, and I want to try something different.

Thanks all

BL

I've been running 4S with a 500w 2100kv motor and 14T on my 450 sport with good results (around 2900-2600 rpm). The 25C Zippy compact 2200mah 4Ss are cheap and only weight slightly more than the 3S I was using. It really needed flybarless unleash the beast though. I thought it was fast before but now with the Robird and RJX head it's like a rocket.

Has anyone seen this yet (H45183). It seems to be a fix for the lack of tail pitch against torque, especially on the 450 pro.

Originally Posted by beenflying

Has anyone seen this yet (H45183). It seems to be a fix for the lack of tail pitch against torque, especially on the 450 pro.

KDE also brought out a metal version