Pyro 700-52 Cut Out

[Stolla]

Mmmmm, you're making it difficult for me, maybe I'll throw it in the rappy, problem is both machines are so light it doesn't show much, compass maybe better option but don't want to touch it with the rewind 4035. Thing is for 3 d and smacking around all these motors are really enough, only time you would want more is the extreme high speed flying. But I have my motor test manouvre which is a very aggressive nose down full cyclic rolling funnel, this makes normal motors bog, here is an old link to a maiden test flight, boring as I was testing motor with wacked out vbar settings but it shows a couple of these manouvres http://m.youtube.com/#/watch?desktop...H8oHgwTk&gl=ZA

[_Dekker]

Originally Posted by smsodhi

OK thanks. Quantum is out. OK. Dont see much love for the KDE. Is it because of the weight?
I like the Idea of the 4525 as so many recomend it. Also like the idea of rewound pyro and 4535 a lot.
I will wait and see what happens with Fast Lad and Kontronik. If they replace it I may sell it and go for 4525. If they do nothing to it I'll get it rewound and get 4535
Where can I get the motor rewound? I am really liking the idea of doing this.
Thanks

I could also do the wind for you, Netherlands is not so far away from you..
Pyro or Scorpion, both are no problem, and I always wind in YY.

Bert

[smsodhi]

Thank you for your kind offer. I will see what happens with the motor then get back to you via PM.

Satnam

[Stolla]

good to know you do rewinds for the masses dekker, don't know why I thought you only do it for friends. Your work is truly formidable
Btw nrpy rewind quantum went to rappie,14.5 pitch, absolute demon, pyro is for sale, sh.t why did I listen to you!

[NRPY]

LOL! That's awesome.

What ESC are you using? Is the Quantum rewind too much for the Jive?

[Stolla]

nope using jive, we can continue discussion on the quantum thread, will log tomorrow if weather ok. But have couple off full pitch pumps with the high pitch, no problem with jive, but rappie is light so let's wait for jlog. man I love this machine, even more now!

[_Dekker]

Originally Posted by smsodhi

Thank you for your kind offer. I will see what happens with the motor then get back to you via PM.

Satnam

I got Satnam's Pyro 700-52 today and already dismantled it to investigate if something's wrong.
First, for all others I must mention that this Pyro has been to Kontronik, with the mention of the problems it had. It was returned with "faulty bearings" and they replaced the bearings and shaft.
This is how Satnam sent it to me, unused. Good thing he didn't.

After taking the stator off I inspected the windings, all OK.
Then I cut the wire sleeves to unwind the motor. This is what I saw underneath:



Yes, a cut wire.. It has been like this for a while because the cut ends were dirty.
No doubt this is the cause of the motor problems.
First thing that comes to mind: did Kontronik not do some kind of impedance test? Surely they would have found the problem if they had done that?

There was no damage on the outside of the sleeving, and the wire was cut exactly at the point where the coating starts to get bare for soldering. Upon closer inspection I could see the wire had been partly cut by the tool for stripping the coating off. The rough pattern of the bare copper next to it confirms that (large forces).
Anyway I'm glad the problem has been found.
I plan to do a 6+7 wind with 1.32mm wire for a n spec around 490.

Bert

[powercroco]

congratulation Bert - neat work to find this out!!!

into the insulation tube it may be, that is gets enough contact to "cheat" their usual no load test.
and if they do not make a full power test, they won't find this mistake.

the reason behind this is, that they use a machine for uninsulating the wires, which scratches around the copperwire
if it is wrong adjusted, it cuts to deep, as you can see here.
may be, a whole batch will have the same mistake.

conclusion:
also the kontronik quality control net still has to big mashes!
you should send them your finding, hopefully, they will learn from it.

[_Dekker]

I was already playing with the idea of mentioning this to K. Will send them a mail tomorrow.

[Stolla]

exellent find, just goes to show how many things can go wrong! Why the slower kv Bert, i find the 6+6 perfect for the pyro, leaves a little space for cooling, maybe 1.25 will be better with 6+7 for cooling and still enough power? Pyro already not the strongest motor anyway.

[smsodhi]

I have to say that I am very disappointed that my motor has this fault and that it caused damage to my heli, and after sending it back to them they failed to find the fault.
We pay a premium to own Kontronik products in the belief that we get a premium product and service.
I am so gad I did not use it after it came back from K.

[powercroco]

go into each motorbuilding factory and you will find uninterested people with lusterless eyes doing their job as easy as they can fullfill it. they have NO interest for the product.
its the same in germany or also in china.

thatswhy we build our motors ourselfes.
if you work only to get your money, you NEVER will be as careful as if you work on your own project!

if it works, you can be proud, that your result beats the best commercial products.

and if a fault happens, there is no room for doubts, who is guilty.

[NRPY]

Yeah, the bright side of this issue is that smsodhi's Pyro is going to rock when Dekker gets done with it.

[_Dekker]

Originally Posted by Stolla

exellent find, just goes to show how many things can go wrong! Why the slower kv Bert, i find the 6+6 perfect for the pyro, leaves a little space for cooling, maybe 1.25 will be better with 6+7 for cooling and still enough power? Pyro already not the strongest motor anyway.

Lower kv will also give a bit more torque for the same amps, and it was Satnam's choice to go a bit lower. Anyway I expect n spec to be more in the 510 range with 13wind yy, not 490 as I said earlier.
Since the pyro runs cool anyway, I want to increase the fill bigtime. Should be 83% more compared to stock

Bert

[powercroco]

but don't forget to warn your mate, that it will run hotter after this rewinding!

the coolness of serail pyro only follows from the streaming air through the coils and the very good fan.
if you fill the free room with copper, the fan won't work efficient anymore - there comes no air anymore to blow out.

you can measure it in b.e. pyro or in to the rewinded types.
the only exception was the one-layer 6+6x1,18 winding with better filling (+25%) AND more room for air compared to the serial type.

[_Dekker]

Originally Posted by powercroco

but don't forget to warn your mate, that it will run hotter after this rewinding!

the coolness of serail pyro only follows from the streaming air through the coils and the very good fan.
if you fill the free room with copper, the fan won't work efficient anymore - there comes no air anymore to blow out.

you can measure it in b.e. pyro or in to the rewinded types.
the only exception was the one-layer 6+6x1,18 winding with better filling and more room for air compared to the serial type.

OK, I know it will run hotter yes, but was under the impression it will not go up to Scorpion heat levels, am I right? I did a 5+6yy 1.32 on the pyro once and that still ran very cool.
Haven't started on the motor yet, so perhaps Satnam wants to chime in here to tell us what he wants for his Diabolo.
Ralph, do you have temp measurements/ comparisons to rewound Scorpion motors?

Just happens that I am making winding tables(work in progress) for all the common motors around and below is the one for the pyro. Many kudos to Werner, he is the originator of this idea.
This might help determining the desired wind. I prefer to stick with the YY column, so wire thickness & n spec still are left as parameters:

[powercroco]

I havn't done it by myself.
but I know about a factory-test of 7 several fan types including a 100% pyro-copied fan on a really good filled stator.
the overall difference was 2°C - measured direct into the winding!
unfortunallyI don't find back the foto of the candidates
but you can try it with pyro.

[smsodhi]

I am happy with what Bert has recomended. I dont mind a slightly lower KV and like the idea of more torque. The ambient temps in th UK are low. I fly a 4525 as hard as I can and temps are only around 70dec C. on the can and windings. I have ventilated my canopy. May get a modified heat sink also. More bling than necessity I think.
Would it get hotter? Even so it would be able to tolerate it, right? I would like it as powerful as possible.
I am thinking low headspeed high torque (1500- 1700) 750 blades on the Diabolo, smooth 3D flying for now with this motor. Then crank it up in the future.

Thank you all for your input and help.

Satnam

[powercroco]

70°C is far away from every danger.
this region begins at about 150°C in winding and 130°C at the pyro magnets.

I'am sure, you won't get the pyro as hot.

[_Dekker]

Thanks for the comments. So I'll just stick with the plan.