Motor builders corner

[olmod]

Hi I think its great to have a forum free from banners ,:)
amongst other things I build motors from all sorts of stators be it from angle grinders to cdroms mainly using the outrunner principle,i will endevour to help
those in need ,and when time permits make some presentations.

[admin]

Hi I think its great to have a aussie forum free from banners ,:)
amongst other things I build motors from all sorts of stators be it from angle grinders to cdroms mainly using the outrunner principle,i will endevour to help
those in need ,and when time permits make some presentations.

olmod,

welcome aboard to WattFlyer.com and we are looking forward to you sharing your knowledge and expertise here.

[Michael Kilmer]

Hi Almod:
From looking at the posting it looks like you have access to a lath?

[olmod]

I have a sheraton super 10'' and some other sheetmtal machines, a lot left over from my own biz making production aids,

[olmod]

If you feel inclined to salvage the motors from cdroms for parts here is a list of very usefull ones to keep an eye open for.;)
AsusS400/A. S500. CDROM DRIVES.
LiteOn LTN-382. LTN244.
L.G.CRD8322B.
Samsung.SCR3232.
Sony.CDU-571.
Toshiba.XM5702B. XM6201B. XM6602B. XM3501B.

[ron_van_sommeren]

There's also a (surprise) power systems forum here:
http://www.wattflyer.com/forums/forumdisplay.php?f=17

[johndalton]

Hey man...was wondering if there were any how to's on "how to" make a brushless outrunner type motor. Ive heard of this, and love to make my own stuff. anyone know how, or know where to point me? Also, if you have a tutorial, you should sticky it.

John

[ron_van_sommeren]

/* oops, wrong planet ... */

[ron_van_sommeren]

www.yahoogroups.com/group/lrk-torquemax (http://www.yahoogroups.com/group/lrk-torquemax) -> FAQ
www.powerditto.de (http://www.powerditto.de) (English and German)

DIY motor homepages and manuals in first message of this motor builders tips and tricks thread. The checks and tests may save you from frying your controller. Thread is active, bookmark it for future refence and subscribe to it:
http://www.rcgroups.com/forums/showthread.php?t=240993

Kit manufacturers:
http://www.rclineforum.de/forum/thread.php?threadid=43664&sid=

[olmod]

I have been trying to scource flat wire in this country for a while ,and now i am rolling my own,what does it mean? more amp turns,more efficiency?
we will soon see.:)

[fdix]

olmod have you finished your motor? Does flat wire make a difference?

[olmod]

Not encouraging results so far ,what happens in fact is the rerolling work hardens the wire raising the resistance too much:( ,ive built motors and done my tests,what is really needed is for the wire to be annealed after rolling then coated,and then i would get the results im seeking. for your interest a 9 turn motor drew 1.5 amps more than round wire,and even increasing the turns too 11 still was not as good. wich also gives an insight into what constitutes a good winding wire ,ie the softer the wire the less resistance it has ;)
some winding wires just before coating are passed through a final sizing draw,now depending upon how much they sqeeze it down relates directly upon how hard it is ,have you noticed the difference in same guage wires from different scources? i have ;)

[fdix]

I was just wondering... I haven't noticed a difference between wires as I've only built one motor so far. It'a a Schnurz

http://www.meinpapi.de/holle/schnurzz/schnurzz.htm

nice little motor I built the 13 turn "star" version with 0,425 wire: weights 16g and gives about 250g of thrust, draws 6.3A on 2s ePower EP450HP.

On a 120g Knuffel performance is interesting :D

Well good luck for your future experiments!;)

[olmod]

I know Manual's work :D he of the golden thumbs:cool: , and his motors are good also, real hot rods of the air;)

[Plane_freak]

I have seen outrunner brushless kits for around $23. Are they hard to build? and how much would they take to assemble?

[BobFlyer]

I have built several of the Komodo 278 kits, and just ordered a couple additional units from Sloper Steve which Is slofly.com for 15.oo each..

They take about two hours to build with no experience..My first unit was a total success..I wound a 13 turn with 24 gage wire supplied..It turns props from 7x5 to a 10x4.7 direct drive on 3s polyquest..current depends on the size of the prop..It was not hard and Komodo has an on line manual
of what the steps are in the build..I would recommend this for a first build.

Hardest part was getting the magnets in the bell..but not much trouble.

If you want a kit with the magnets aready installed, the Apex mini 300 is
also a very nice kit and inexpensive..I tried one of these and it went together without an problems at all..There are several others, but so far, I have not tried any other than the two above..The kits give you the idea of what is involved, and perhaps in the future, one could branch out and buy the individual componets(gobrushless.com) required for a specific build requirement.

Give one a try, install it in your plane, and tell your friends, I wound the motor myself..

BobFlyer :)

[Plane_freak]

I realize that most Brushed motors have a limit, usually around 9.6 volts. What will a brushless motor handle as far as voltage?
Thinking of buying Formosa. Should I get the 300 or 400 how much more power does the 400 draw? Will size of esc would I need?

[BobFlyer]

Most motors that are brushless have recommended specifications from the manufacture. However, in general most handle the 3 cell lipo's cells at 11.1 volts and the nimh 10 cells or 12 volts. Some can handle even higher
voltage such as a small Littlescreamer works at 14 volts..However, keep in mind the total wattage of the motor..I.E. Power in Watts=(current times voltage) Wattage is the important consideration when operating. Since so many different voltages/current combo's can arrive at the same wattage. Hight current low voltage, high voltage low current..ect.

As to the Formosa, I have no experience with this plane an its setup. Difference will be again the total wattage the motor is capable of operating within..The 300 has a smaller wattage rating than the 400 but weight is slighlty less and current demand is less somewhere around 8 amps, on the other hand the 400 series can handle somewhere around 10 amps. Another consideration is the Current/Voltage handling of the Speed Controller, they are rated for various current/voltages also. Make sure the speed controller can handle the voltage you plan on using and the current
requirement of the motor. Plus if you plan on using more than 3-4 servos you need to consider the current rating of the speed contoller to handle this current..the BEC is generally rated at around 1.5 amps plus or minus..
So it pays to buy servos that draw small amounts of current..The hitec hs55 are easy on current requirement(just and example)

One item that is almost a must have if you plan on flying electic airplanes is a Wattmeter, this will tell you how much current at what voltage and total watts being drawn from a given setup..Different Props will draw different current and load the motor differently.. With a Wattmeter, you can be assured that you are within specifications.

The Asto Wattmeter 101 is very good unit as well as several
others..Makes the measurements very easy.


Happy Flying...BobFlyer

[olmod]

Laptop motor.
Just finished testing a small motor built with a stator ex laptop hard drive parts stator size 16.7x2.5mm
wound 35 turns of .2mm connected y .. 12 , 3x3x.5mm n50 magnets.
gws 4540 7.2v 2amps 8800 rpm = 62g thrust measured .
gws 5043 7.2v 2.1 amps 7600 rpm = 72g thrust measured.
weighs about 7 grams with the gws 5030 prop fitted.
cheers Lez.:)

[Stuntman]

I need to go and have a look at the text books, but you should be able to regain some of that lost resistance by stress relieving maybe even in the range for a light anneal in a home oven. 220 for a couple of hours should do it, without adversly affecting the enamel

Just bake a cake (a just add water packet mix will do it) to disguise the real use for the oven. :D

Shawn

[olmod]

there for a few seconds:D until i reread your post,you are of course refering to my experiments into flat wire , I really dont want to regain resistance ,i want to lose it :) to fully soften work hardened copper you must heat it to a dull red heat visibly, then before the air can cool it quench it in water straight away, my basic trade was a sheetmetal worker and one of the firms i worked for was Rodd aust' mfg of jewelly, cutlery,
medals,motor laminations, some of the souvineer spoon ends were made of copper and that was part of the process used,what you suggested is more in keeping with stress relieving injected moulded plastic components wich in my later working life i was concerned with, as i designed and built the ovens used to do just that to automotive tailight lenses.thanks for your interest and input and please dont be put off by any ill conceived idea im trying to put you down ,ok? cheers Lez.:)

[Stuntman]

there for a few seconds:D until i reread your post,you are of course refering to my experiments into flat wire , I really dont want to regain resistance ,i want to lose it :)

That what I meant to say , I just sort of did it in a round about, inappropriate way.. :rolleyes:

Anyway I feel I am suitably qualified to speak on subject, being a metallurgist and all:D (but with a steel focus).

Ok after reviewing the necessary texts its aparent that (assuming the wire is relatively pure), that reductions up to 80% only decrease the resistivity by 3-4%, so its marginal at best. In fact any impurtities or alloying elements will have a more significant effect.

Stress releiving at 200-250 may give you a marginal improvement. A full anneal is not required in my opinion and would destroy the coating anyway.

Cheers, Shawn

[fdix]

I was given a HC2808-0980 with damaged windings so I rewound it ;)
The motor is 12N14P. I wound it AabBCcaABbcC. For now with 0,4mm wire, 10 turns star.
With a GWS EP1047
@2s 6,1A 2,7N thrust
@3s 8,7A 4,2N thrust

I'll optimize the motor for 2s and hopefully 5N of thrust

update:

last version is 8 turns star 0,5mm wire. It is a step in the wrong direction @3s around 10A with 3,2N thrust on a GWS EP0947.
This version could be interesting with small fast props, but that is not what I'm looking for.

[shrike]

I was given a HC2808-0980 with damaged windings so I rewound it ;)
The motor is 12N14P. I wound it AabBCcaABbcC. For now with 0,4mm wire, 10 turns star.
With a GWS EP1047
@2s 6,1A 2,7N thrust
@3s 8,7A 4,2N thrust

I'll optimize the motor for 2s and hopefully 5N of thrust

update:

last version is 8 turns star 0,5mm wire. It is a step in the wrong direction @3s around 10A with 3,2N thrust on a GWS EP0947.
This version could be interesting with small fast props, but that is not what I'm looking for.

Hope this helps:)

I wound a series of 12n14p the same way on 25mm (slightly larger dia.) by 4mm (half your depth) shooting for two cells on a 8x3.8 APC at 6.5A or less. I found 12 turns good for high current applications and 14 turns for lighter weight lower current (20C 340ma) cells I wanted to use.

12 turn - 8.3A 11.9oz static (3 strands of 28 guage) ~=0.53mm dia
14 turn - 5.5A 10oz static (2 strands of 28 guage) ~=0.45mm dia

The calculated Kv was 1505 and 1346 respectively

[Joe Lang]

I have built several of the Komodo 278 kits, and just ordered a couple additional units from Sloper Steve which Is slofly.com for 15.oo each..

They take about two hours to build with no experience..My first unit was a total success..I wound a 13 turn with 24 gage wire supplied..It turns props from 7x5 to a 10x4.7 direct drive on 3s polyquest..current depends on the size of the prop..It was not hard and Komodo has an on line manual
of what the steps are in the build..I would recommend this for a first build.

Hardest part was getting the magnets in the bell..but not much trouble.

If you want a kit with the magnets aready installed, the Apex mini 300 is
also a very nice kit and inexpensive..I tried one of these and it went together without an problems at all..There are several others, but so far, I have not tried any other than the two above..The kits give you the idea of what is involved, and perhaps in the future, one could branch out and buy the individual componets(gobrushless.com) required for a specific build requirement.

Give one a try, install it in your plane, and tell your friends, I wound the motor myself..

BobFlyer :)

Bob, The Komodo 278 kits from komodohobby.com are coming through with the magnets already installed in the bell. Apparently, customers were messing up the installation so now the supplier does that part for you.:D

Joe Lang

[fdix]

Hope this helps:)

I wound a series of 12n14p the same way on 25mm (slightly larger dia.) by 4mm (half your depth) shooting for two cells on a 8x3.8 APC at 6.5A or less. I found 12 turns good for high current applications and 14 turns for lighter weight lower current (20C 340ma) cells I wanted to use.

12 turn - 8.3A 11.9oz static (3 strands of 28 guage) ~=0.53mm dia
14 turn - 5.5A 10oz static (2 strands of 28 guage) ~=0.45mm dia

The calculated Kv was 1505 and 1346 respectively

Thanks!
I tried 9 turns with the 0,5mm wire: very tight, indeed I got a short somewhere :mad:

It's getting late (2:20 AM) so I'll try 10 turns 0,425 tomorrow! ;)

[olmod]

those darn sharp edges:( ive tried all sorts of ways and one foolproof way is to have a selection of thin walled larger than the pole piece lengths of heatshrink you just slip a piece over each pole and shrink ,you have to try to get the length by trial and error but when you have its great.:D

[fdix]

In the end I wound the HC2808-0980 9 turn star with 0,425 wire.

With GWS EP1047
@2s 7,5A 3,2N
@3s 10,5A 4,7N

With GWS EP0947
@3s 8,5A 3,8N

I think I'll keep this setup. It is rather close to the original winding. The motor will go on a <250g aircraft so thrust/weight is good.

[olmod]

In the end I wound the HC2808-0980 9 turn star with 0,425 wire.

With GWS EP1047
@2s 7,5A 3,2N
@3s 10,5A 4,7N

With GWS EP0947
@3s 8,5A 3,8N

I take it that ''N ''signifys RPM

[fdix]

I take it that ''N ''signifys RPM

N stands for Newton (SI unit for force)

m = F * g

g on our planet is 9,81 m/s^2, m is mass in kg, F is our force.
In short to get a value in grams all you must do is multiply the force in Newton by 98,1 (100 :) )

[olmod]

I have my own motor testing dynometer and the output is in dynes but always with rpm :confused:

[fdix]

Well I have a tachometer in my radio, a Futaba T-9Z, but I was too lazy to use it :D