Fore test I'm using one FMS 69mm 6b EDF.

3s= 11.09V, 11.26A, 124.8W, 21,505rpm, 93.86%NLS.
4s= 14.62V, 17.74A, 259.3W, 27,624rpm, 90.42%NLS.
5s= 18.55V, 26.52A, 489 W, 33,783rpm, 88.47%NLS.

Fore 6s lipo I going to test in the airplane.
Projected: 776Watts, 35.?A, 39,000 rpm.

big 6slipo. 23.97V, 40.02A, 959watts, 42,016 rpm, 84.15%NLS. 99.2 db to 2mts rear.

To 22.07Volts, 34.39A, 38,910 rpm, 759.3 watts, 86.4%NLS. 8.93w/g.

I'll bet that is pretty hard on the ears, you need some of those shooting ear muffs...

Jack

Jack.

Not, only around 90-92 db.

It that all? I'm the guy that has been wearing a pair of hear aids for the last 14 years or so, I should have known that. At 91 dB a one or two hour exposure will not damage your hearing...

Jack

Jack.

My old F86 with Dynamax fan and KB .91 motor with Tom Cook pipe has 108 db.
Is terrific sound. Very bad for the ear
You have to wear earplugs.

Well balanced EDF are quite silent. even Dynamax fan.


This EDF I'm using, I have worked in the range of 37,000 rpm and have worked very well.
I am now growing some rpm, hopefully smoothly.
I do not know which is the limit for them, but does not look much above 40,000 rpm.

What I see is that now the motor is more efficient, because in my test 5slipo, rpm getting more of the same power.

I have to turn my hearing aid off for small props when they get up around 20,000 or so. My hearing aids amplify some sounds more then others and it makes me crazy!

Most of my hearing loss is from wearing headphones and copying Morse Code... And working in rooms full of electronics cabinets that all had cooling fans in them also making noise...

But I get the hearing aids for free from the vets now, very good ones too.

Jack

Now I have doubts about the noise.
I will check the decibels, measuring a meter from the exit and entry.
See what happens and how loud they are.

This motor is what will install an old Habu, with 2s3s2200ma batteries.

I have a new version of TC 7.1 now tells me Rm. Delta an Star.
It is neccesary to feed the length of the original wire and wire resistance used. Also included in the table.

I did a test with a very large battery of 6slipo and have marked much voltage.
big 6slipo. 23.97V, 40.02A, 959watts, 42,016 rpm, 84.15%NLS. 99.2 db to 2mts rear.

Take a decibel reading. and 2 meters gives me 99.2 in a closed room. measured at the output.

Interesting, I never had a dB meter so googled sound levels:

https://www.chem.purdue.edu/chemsafe...n/dblevels.htm

That is a pretty quiet motor...

Jack

A decibel meter, does not have much use, my son bought it to calibrate home theater And I just play with occasionally.

Once the rotor balanced, I feel very quiet.
A 24 volts, is giving me at least 3,000 rpm more than you give me the 2200ma batteries. Now if you'll be in the range of 39,000 he was looking for.

A motor 85 grams to over 959 watts. more than 11w/g EDF only.

I'm rewinding a motor 2839-2750
This motor has a stator of 22.05 x 22.66mm,
With a weight of 27 grams and 37.1 grams with wire.
Its slot has 3.7x3.7x3.9x2mm with an area of: 10.545 mm2.

So that is predicting 10.45 turns for the slot dimensions you entered? Is that right?

I noticed one typo also...

Jack

in block 4 it tells me that 10,545 is the area in MM2
and in block 5 it tells me how many turns maximum per slot with each one of the wire gauges. (this table is not finished)

In this case I decided to do it with 21AWG wire

There is a fact that does not make clear.
this motor has a winding with 6 turns perdiente in ABC x3.
In a symmetrical winding the resulting Kv has very few options and changes a lot with every turn of difference.
6t = 2750
5T = 3300
4t = 4125.all in delta.

Then I decided to feed the data with the sum of the 3 teeth that each phase will carry.
6x3 = 18

then feed the yellow box with 18 and the new Kv with 24 to get the new Kv.
In the end my intention is to put 25 turns / 3 for a 9-8-8.
This way I will get a more appropriate Kv to what I am looking for from 3429.

I am practicing the YYY winding, which is somewhat difficult but also comfortable.

I'm going to go off and study this a little, I think I am hopelessly confused at this point.

I ran the spreadsheet and have what you see in the attached now, are the yellow block entries I have on that now right?

(I won't get back online until tomorrow some time... No rush on a reply)

Jack

In block 5, column E, green and white, tells us according to the surface of the stator slot, the maximum number of turns that can be given. (consider that all teeth are rewound)
I consider a maximum of 70% of the slot surface.
Some may do more than that, but for the normal rewinder that may be the limit.

In column G, Yellow and white, we feed the turns that we are going to use and we will see in column I, green and white the% copper in the stator. here if you consider the two teeth.

in this way we compare the difference between using a caliber and another of smaller diameter.

Each one will have to decide which size to use, either for ease or for wire disposal in their stock.

This data helps us to decide if we use a double or single winding, in delta or star.
always looking for the highest copper packing for the available wire and the desired Kv.