850,kosmik 14s

[Stolla]

Guys at last got this going, please view here https://www.helifreak.com/showpost.p...19&postcount=9 lets try keep the logo discussions here and motor discussions that side if possible.
In short its a fantastic setup power reminiscent of my hv with the handwind 4035yy but off course the logo bigger and heavier as well as longer blades now is a monster, at last the way i like it.
Luckily i didnt get kosmik troubles or tail wags, so finally i will give this machine a big

[NTM]

Which blades Stolla ?
I got around a dozen flights on mine with the kosmik/pyro 800-48/14s 4400mah and edge 713se blades now.
Cyclic response and precision is outstanding, but the collective response leaves me wanting more.
I just threw some 753mm on yesterday evening, but our weather took a turn for the worse, and have been unable to try them.
Are you running something bigger than 713's ?

[Stolla]

Excellent, lets compare logs, i know different flying styles etc but will form a base comparison. No im using stock everything except motor and esc. Why not go higher pitch and add more pitch pump?
Have you flown 4525 stock on 12 for comparison?, please post. Lov file i tried on tab but need to change the lov to txt or jpeg, then convert to watch, dunno how to do on this thing so will from pc later.

[NTM]

I can't get the lov file to upload, it's fairly large.
Just swapping the log file would be easier.

It was 14s from the start, it weighs 12.6 pounds.

I'd rather not go above 2100 rpm to compensate for higher disk loading because I like to fly 1700 rpm sometimes for slow smack and practice flights. I also prefer the feel of a more lightly loaded disk, 620mm on my logo 600's, 710mm on trex 700e, etc.

Going deeper on the pitch, I'm at 12.5 degrees now, will help a little, but the behaviour I don't like is the "slipping" of the disk before the heli really takes off. That's generally directly related to disk loading. The "crispness" of the acceleration on collective...
And after living with it for a bit, the logo 700 really isn't a 700, in the same way that the logo 500 wasn't a very good 500mm heli. They're both derived from larger machines and end up better in the middle somewhere, 550mm for the 500, 750mm for the 700. This is all in my mind though, as our weather currently sucks, and I've no data or observations on the 750mm blades. So I could be wrong.

The logs are only showing peaks in the 160 amp range, around 8000 watts. Sustained tic tocs for a full minute won't see any peaks over 100 amps, and don't pull the packs voltage down appreciably. Pwm output hits around 95 in the 160 amp peaks.
Seems pretty effecient with lots of "felt" grunt in flight, but the 750mm blades will tell the story as far as power goes.
With the 713's, I just couldn't seem to load them enough to really work the motor.

[helicraze]

Let us know how 750mm blades go

[Stolla]

I wonder if changing to a different blade maybe Se or v2 will make a difference, for sure the extra weight makes a difference so a lighter machine will always have better collective acceleration. Ive accepted the heavier "feel " though so doesnt bother me. Please try download your. Lov file, rename. Lov to. Txt to see if that work, i will rename back to. Lov I would like to see and compare rpm changes under load etc. Today i was able to fly harder and keep max at 150 with better collective management so i like this setup more and more, its gonna be hard to replace this motor with the 800, but i may be surprised who knows

[Stolla]

Seems renaming .lov doesnt work anyone knows how to post .lov files?

[andersn]

just paste it on external resource, .zip is a good way to archive it, also shrinks it quite a bit since its repetetive data.

[NTM]

I was running the 713 se blades.
I'll work on the file later today.

[Stolla]

I dont see zip files as a valid extension, ah well lets do this through normal email,we can post the graphs as jpeg

[MrMel]

Ask Will to allow .lov as its just a text file

[NTM]

Originally Posted by helicraze

Let us know how 750mm blades go

You bet, as soon as I can.
It's -31 here today, the dampers were giving me fits on hard collective stops and reversals in 0 degree weather, so flying today or the next few days is out of the question.
I'm itching to know how well the pyro deals with the bigger blades though...

Btw there is no good solution for spacers for 14mm root blades like the 753mm edges.
I ended up machining shims to my own requirements for them.
You need 3.69mm worth of spacing on either side of the blade root, and it has to be fairly exact due to the rigidity of the blade grip.
Hopefully mikado will recognize this oversight and make their own spacers to use 753mm edges on the logo 700.

[Mentalic]

Originally Posted by NTM

You bet, as soon as I can.
Btw there is no good solution for spacers for 14mm root blades like the 753mm edges.
I ended up machining shims to my own requirements for them.
You need 3.69mm worth of spacing on either side of the blade root, and it has to be fairly exact due to the rigidity of the blade grip.
Hopefully mikado will recognize this oversight and make their own spacers to use 753mm edges on the logo 700.

Just installed a set of 753's on my Logo700 today. Would like to see a set of metal/plastic blade grip spacers too, really don't like the down sides of metal to metal contact. So to get the 753's on there I had to use an ugly stack of smaller metal washers with plastic next to the blade grips. Back to the blades, I really like the lighter loading and you just don't need allot of head speed as it will move quick. I'm leaving the 753's on it until something in between is available. Running 1700, 1800, 1900 rpm.

[NTM]

I'm hoping for something in the 730mm range myself...2050 rpm on those'd be perfect.

[Stolla]

You guys are building 800's now, the viscious circle. Personally i like the way it flies with 713, maybe because my e720 has 693 on. Slower heavier but very precise and different in a nice way. Will be interesting to see how this pans out though.

[NTM]

No more an 800 than the logo 500 is a 600.
It's just an in between size, which isn't a bad thing really.

I'll be happy when it's got the same "pop" as my goblin does at 2100 rpm on 696mm blades.
The logo 700 cyclic feel and behaviour is superior to the goblin by far though.

[Stolla]

Tbh i dont see how you gonna get goblin pop on the much heavier bird, to move the extra mass you will need exponentially much more power, longer blades will help but then you fight the law of physics with flip and roll rates, you may get close to the feel maybe, lots of pitch, high pitch pump value, dunno if the 800 will have enough grunt though. Pop is initial acceleration so at the same time you accelerate the extra mass you also fight the extra drag and resistance of the longer blades. I would think running the 713's 100rpm higher would do more for extra pop than longer blades at lower rpm,There is a sweetspot however so will be interesting to hear your findings. Maybe change to a stock mx motor in goblin or lower headspeed, then you can have the same pop

[Stolla]

Had a look at your log Nathan, difficult to say compared to mine as different helis different pilots, however at your max peak i saw a fairly large overspeed of about 200 rpm, can you remember what manouvre you did during your highest peak?, also what pinion?
its a known fact that larger motors produce lower peaks so i gues the only real proof will be in flying and feeling the different motors. it seems the "working" range of the 850 is in the 130 amp range anf the 800 about 110 and peaks probably very similar as i had 175 peaks the previous day. So what did we learn. nothing really, i will have to log the 800 and compare similar flight to get the true result. Also what is your max pitch?

[kevinbj]

I would like to know about rail 716 on this bird

[NTM]

The peak was just a tail slide into a hard stop using full collective, 12.5 degrees, and full cyclic.
So it unloaded hard after the stop.