Align 850mx "dominator"

[Vinger]

Reviving an old thread, just got hold of a brand new 850MX and want to wind it for 520KV, and either Delta or YY, anybody out there done this? Turns and wire thickness? Or tips or tricks with this 4530 size motor?

Original is a 490KV but testing it found the nSpec to be 450KV with YGE 18 deg. Not sure how many turns as I still have to take it apart.

[_Dekker]

Originally Posted by Vinger

Reviving an old thread, just got hold of a brand new 850MX and want to wind it for 520KV, and either Delta or YY, anybody out there done this? Turns and wire thickness? Or tips or tricks with this 4530 size motor?

Original is a 490KV but testing it found the nSpec to be 450KV with YGE 18 deg. Not sure how many turns as I still have to take it apart.

This is one of few I have not done yet, but:
Based on the 800mx and very big chance that the magnets have the same width (stator is only stretched):

Ratio in stator length: 35/30mm =1.167
You want 520Kv for 850mx.
--> 800mx equivalent is 520*1.167 = 607rpm/V

Following options are based on what I have measured on the 800mx:
Option 1: 9turns Delta for 617rpm/V (800mx) --> 30/35 * 617 = 529rpm/V for 850mx
Option 2: 11turns YY for 584rpm/V (800mx) --> 30/35 * 584 = 500rpm/V for 850mx

I would aim for max 18.5mm^2 to avoid issues with saturation and esc shutdowns. This should already be about 70-100% increase over the stock wind.

For Option 1: 9t with1.6mm wire for 18.1mm^2
For Option 2: 11t with 1.4mm wire for 16.9mm^2 (or 1.5mm for 19.4mm^2 but a bit risky)

[krtek2k]

Hello Dekker.
So do you think , when i done 800MX YY 13(7+6) 1,5mm = 22,93mm2, so it can have issues with saturation and esc shutdowns?
Uuupps... it still not was in the air, so i dont know for now, how it will works.

[_Dekker]

Originally Posted by krtek2k

Hello Dekker.
So do you think , when i done 800MX YY 13(7+6) 1,5mm = 22,93mm2, so it can have issues with saturation and esc shutdowns?
Uuupps... it still not was in the air, so i dont know for now, how it will works.

I do not know the absolute upper limit.
I have done 750mx in the past with >22mm^2 and that was definitely too much: esc shutdown in mild pitch pumps.
The hammer stalks on the 800/850mx are wider so you might get away with it.

I took 18,5 as limit for now since the improvement is already very nice and I know for sure it is not too much.
On the 700/750mx I put it at 17-18mm^2.

Any people who can confirm high fill factors to work without issues in hard 3D flights are of course welcome to report here

[Vinger]

Thanks, will report back when I have it apart and test wound, unfortunetly real work has interfered and it might only be in a week or so. Will start with 5+6 YY and see what the KV is, plan on using 1.4mm wire for the final wind as that is what I have in high quality wire.

Considering a Delta termination as well as the motor will be used with Kosmik which is supposedly optimized for Delta terminations.

[omerco]

Some help please:
anybody knows how the fan is installed to the can (the part holding the magnets) in those motors? is it screwed or just glued? what is the best way of taking it apart without taking off the magnets?

I got a motor for a rewind and test wind showed great vibes due to the can not installed straight on the fan. so it looks like taking it apart and re-assembly is in order.

[KSHeli]

On my 700MX motors there are 2 grub (set) screws in the fan end that once removed you then press the shaft from the fan end towards the pinion end of the motor, then you can just pull the fan from the can.

So look in between the fans for the hex set screws (grub screws).

[omerco]

Thank you for the answer but I don't think we are talking about the same thing: you refer to removing the whole bell from the stator'
In my case the motor is already apart. I need to take apart the fan - the upper part of the can itself - from the can - the tube with the magnets.

[KSHeli]

Originally Posted by omerco

Thank you for the answer but I don't think we are talking about the same thing: you refer to removing the whole bell from the stator'
In my case the motor is already apart. I need to take apart the fan - the upper part of the can itself - from the can - the tube with the magnets.

Sorry, don't know about that, but I would suspect that it was welded (fused) to the can.

[_Dekker]

Originally Posted by KSHeli

Sorry, don't know about that, but I would suspect that it was welded (fused) to the can.

I don't think so. Kontronik uses some kind of snap in, you can drive the parts apart by hammering on the shaft.
Don't know about Align but to me it looks like a press/bonded fit. Should come apart in the same way.

[omerco]

Took 5 seconds and 3 punches. 10x dekker.
What would you recommend for gluing it back?

[_Dekker]

Originally Posted by omerco

Took 5 seconds and 3 punches. 10x dekker.
What would you recommend for gluing it back?

Thorough cleaning and Loctite 648.

[omerco]

As thought thank you again. can is fixed.

Did a test wind and got very strange results. would be happy for some experts opinion here:
When testing on 6S i get this, showing 472KV:


But then on 12S i get much higher amps and the KV spikes to strange values - 650!!:


Also note the instability of voltage+RPM fluctuations. This is not the first time it happend to me with Castle the same happened with Scorp 4020. it looks like it has some trouble with some of the motors.

Still the RPM with 12S doesn't fit that motor's data and is strange. Will test again with my YEP Where i know it will be more stable.

[omerco]

OK did another test with the YEP ESC. the RPM was a little more stable and motor ran smoother - but the strange results are still here:
22 V gives 470KV
44 volts give - 630KV

What do you think about this guys?

[_Dekker]

Originally Posted by omerco

OK did another test with the YEP ESC. the RPM was a little more stable and motor ran smoother - but the strange results are still here:
22 V gives 470KV
44 volts give - 630KV

What do you think about this guys?

The voltage does influence the kv but this is quite a large spread. I only test at about 13V, 44V is quite high without load.
Are you sure there is no governor active and you are really at 100% throttle?
Motor pole count set correctly?
What wire did you use for the test wind, already very thick (possible saturation issues)?
Sure the winding scheme and termination are correct?

[omerco]

Originally Posted by _Dekker

The voltage does influence the kv but this is quite a large spread. I only test at about 13V, 44V is quite high without load.
Are you sure there is no governor active and you are really at 100% throttle?
Motor pole count set correctly?
What wire did you use for the test wind, already very thick (possible saturation issues)?
Sure the winding scheme and termination are correct?

- All my ESC's are on airplane as i only use external governor - so no governor engaged.
- verified 100% throttle on both the castle (erasing log at full throttle) and the yep (light turns off at full throttle).
- motor pole is right and verified. i measured the rpm in 2 different ways.
- wire used is 0.6. I'm taking apart the motor now to do a new rewind with thicker one to see if it makes a diff.
- winding is half of YY there is no much room for mistakes but verified that as well - but even if it was wrong i would expect a more stable KV through the range.

EDIT: the most important thing is i can't understand the 630-650KV: Dekker as per you calculation earlier in this thread 11T YY should be around 500. one of the guys wrote he tested an original to find the kv is lower than stated so that fits around 470KV as i got with 22V
Where the hell is that 630 coming from?

[omerco]

OK Checked again the YGE and i was missing 3 clicks for full throttle (this is not relevant for the castle i still can't understand what went on there).

Testing at 6S yielded 640KV on 11T half YY. That is instead of an expected KV of 500+-...on 12S - 657KV



Damaged magnets?

In general it is very easy to take the bell of the stator it does fill like the magnets are not too strong but i was blaming the low quality for that.
I was told the motor used to run hot before, and it was on an 800 machine and got burned nicely.

[_Dekker]

Originally Posted by omerco

OK Checked again the YGE and i was missing 3 clicks for full throttle (this is not relevant for the castle i still can't understand what went on there).

Testing at 6S yielded 640KV on 11T half YY. That is instead of an expected KV of 500+-...on 12S - 657KV



Damaged magnets?

In general it is very easy to take the bell of the stator it does fill like the magnets are not too strong but i was blaming the low quality for that.
I was told the motor used to run hot before, and it was on an 800 machine and got burned nicely.

What timing do you use with the ESC? High timing gives you high kv. But I do not expect such a big difference.
Also I believe I deduced the required wind from a 800mx (I have not done a 850 yet). This only holds if the stator, bell and magnet design are the same (so only a different stator length). If for instance the magnets are narrower/thinner the Kv increases. That is the first thing I'd suspect as being different.
Same applies for overheated magnets: higher Kv.

Also keep an eye on the no load current: At 12-14V I have yet not seen higher than roughly 3-4A. If it is much higher something is going on, but do test at about the same voltage (3s lipo)

[Vinger]

On my way home and should have time to do a test wind, also plan 11T (5+6) YY and see what I get, my example is brand new, so maybe will get better info about KV.

From the website below it looks like 10T gives 490KV and 9T yields 540 KV

http://translate.google.co.za/transl...tm&prev=search

[omerco]

I have done my calc, as vinger wrote, according to original 10T yielding 470-490 kv, so 11T YY should give around 500+ and not the 640-650 im seeing.

No load current at 22v was around 1.5-2A. Will test again at 3s.

Using 18deg for timing.