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-   -   DIY Motor Turns & Winds (http://www.rcuniverse.com/forum/brushed-brushless-motors-speed-controls-gear-drives-123/3684657-diy-motor-turns-winds.html)

PilotLight 12-23-2005 11:42 AM

DIY Motor Turns & Winds
 
1 Attachment(s)
What wire, How many turns, How many strands, Star or Delta...?

After looking for nearly 2 weeks, I still don't know how many turns to wind a DIY motor. I bought the DIY 300-3 from www.Allerc.com and it had NO instructions. The website says they're coming later, but I haven't seen them yet.

The info I have seems to be misleading. I've read that to get more torque with slower rpm (to turn a 9x4 prop, say) you need a lower Kv. To get a lower Kv you need:

A. thicker wire with fewer turns.
B. thin wire with more turns
C. Multiple strands of thin wire with more turns
D. NONE of the above are correct ???

Looking at a Rimfire 22M-1000, it looks like they used 3 strands for each wind (can't see how many turns) I would like to use a 3S Li-po to fly an 11oz 3D plane with this DIY Motor.

Can you guys give me some idea of what you used and where you found this info?

jdetray 12-23-2005 12:53 PM

RE: DIY Motor Turns & Winds
 
First of all, you should contact AlleRC and demand instructions!

Is your motor the same as the Apex Mini 300? It looks similar, in which case [link=http://www.stuffwelike.net/files/mini2.pdf]this instruction sheet[/link] might help you.

And so might [link=http://www.rcgroups.com/forums/showthread.php?t=359495]this discussion thread[/link]. And [link=http://aircraft-world.com/prod_datasheets/ac-diykit-01.htm]this web page[/link].

More turns will result in lower Kv = lower RPM, more torque, larger prop.
Fewer turns will result in higher Kv = higher RPM, less torque, smaller prop.

The normal procedure is to decide how many turns you need (based on experimentation or the experience of others), then choose a wire diameter that will maximize the amount of copper on the stator. That means using the largest wire diameter that allows the desired number of turns to fit.

Instead of a single large diameter wire, you can use 2 or 3 smaller wires instead. I've never wound a motor with multiple wires, so I can't provide any advice about it.

- Jeff

Bevo 12-23-2005 11:44 PM

RE: DIY Motor Turns & Winds
 
Here's the instructions from Go Brushless.com. This will help you to build and understand how to wind your motor.

http://www.gobrushless.com/GBL_single_v2.pdf

The allerc brushless motor kit is a good kit to start with. In the future if you really like building your own motors look at the Custom CDR's that you can buy from Go Brushless or Custom CDR direct they rock.



Bevo

PilotLight 12-28-2005 12:07 AM

RE: DIY Motor Turns & Winds
 
The information you gave is helping. There are some points to your responses that are narrowing it down for me. BUT, it still doesn't give me specific data. Here are QUOTES from the two above posts:

"The normal procedure is to decide how many turns you need (based on experimentation or the experience of others)" (post #2)


"Based on measurement data (or a wild hair) you will need to decide the number of winds for your motor." (Post #3, PDF file)


The first step in winding your own motor is deciding what size wire, how many strands, and how many turns you will wind to get your desired motor. I still haven't gotten past that first step. The DIY 300-3MM comes with " 0.32 mm wire (enough for two or three winding sessions)" so I would like info on this wire if possible.

Please, somebody must know where the info is...

Bevo 12-28-2005 05:14 PM

RE: DIY Motor Turns & Winds
 
You have a 20mm stator. You need to use 26 or 24 gage wire. You can buy 26 gage wire from Radio Shack. It's called Enamel-Coated Magnet Wire. It comes with 30, 26, and 22 gage wire. It's about $5.00. If you use the 26 gage wire then you'll want to do 17 turns. If you can find 24 gage do 13 turns. Use a GWS 8x4 HD propeller with both setups. The wire that comes with the DIY motor is 30 gage wire you'd probably have to do 30 turns or more to get the power up to what the 26 or 24 gage wire will do. The info that I provided is what I've experimented with and what I like. That's the neat thing about winding brushless motors is you can always rewind them if you need more power or torque. Hope this helps.



Bevo

PilotLight 12-28-2005 06:29 PM

RE: DIY Motor Turns & Winds
 
O.K. Thanks for the info. I think I will start with your recommedation and see how it does. We need some kind of table or calculator that will predict results. I'm going to call Allerc.com to see what they have to say, too.

Thanks again.

More info is always appreciated...;)

PilotLight 01-01-2006 06:25 PM

RE: DIY Motor Turns & Winds
 
I was just informed I should use the stock wire that came with the kit and wind the motor with 25 turns. This will allow me to turn a 9x4 prop with a 3 cell lipo battery. Anyone have any experience with this setup? How many amps?

Bevo 01-02-2006 12:39 AM

RE: DIY Motor Turns & Winds
 
The higher the turn the lower the amps so you can use a larger propeller. You will probably be around 5-7 amps.


Bevo

olmod 01-09-2006 04:58 AM

RE: DIY Motor Turns & Winds
 
Replying to post 7 i very much doubt that you will get the thrust needed from those specs' sure it will drive that size prop but not at the power you need,
have a look at one of my build spec's and judge for yourself.
GB 20mm 22 t x .45mm Y
12 5x5x1 n50 mags'

no load 10750 rpm @ 7.5v @.6 amp
no load 15400 rpm @ 12.25v

GWShd 8040 @ 7.1v @3.8 amps @7000 rpm= 233.35 g thrust
= 8.24 oz thrust.

GWShd 9050 @ 7.1v @5.2 amps @5500 rpm =272.24 g
thrust =9.62oz thrust.

GWShd 1060 @7.1v @6.2amps @4900rpm=300.24g thrust
= 10.6oz thrust.
3sp
GWShd 7035 @11.2v @ 3.9 amps @11500rpm = 289.94 g thrust =10.23oz.

GWShd 8040 @11.2v @6.25amps @9000 rpm =395.59oz thrust = 13.97oz thrust,

cheers.

olmod 01-09-2006 07:52 AM

RE: DIY Motor Turns & Winds
 
I should add i have not tested for larger props.

forktail devil 01-26-2006 06:33 PM

RE: DIY Motor Turns & Winds
 
alright guys, i have a 15'' by 15'' pizza box flyer, i have not yet put it together but the weight so far is 8ounces with all the rc gear and battery except motor and esc, i need a motor for it. i wanna go brushless outrunner but want something cheap, i was thinking about a Custom CDR motor kit, but i dont know how hard it would be to wind a motor. It would have to run on a 2 cell lipo 1250mah. I am in college, so cost is an issue. How hard is it to wind a motor? or does anyone have any suggestions for pre-made motors that are cheap. any help would be great thanks

olmod 01-26-2006 07:59 PM

RE: DIY Motor Turns & Winds
 
If you just want to fly these are the go http://www.hobby-lobby.com/brushless-skatty.htm but if you want a kit the komodo 283v2 takes a lot of beating. cheers.

PilotLight 02-17-2006 12:23 AM

RE: DIY Motor Turns & Winds
 
Just wound my DIY 300 with 2 strands stock .3mm wire and 12 turns. The motor pulls a 8x3.8 prop like you can't believe! The question I have is:

The motor gets hot, almost starts to smoke on 3 cell lipo. Am I going to burn this thing up?

Please reply. I now wish I would have wound a single strand with 26 turns for the 3 cell, but there was no info on 2 strand windings that I could find.

Thanks....

jdetray 02-17-2006 12:50 AM

RE: DIY Motor Turns & Winds
 

Quote:

ORIGINAL: PilotLight

Just wound my DIY 300 with 2 strands stock .3mm wire and 12 turns. The motor pulls a 8x3.8 prop like you can't believe! The question I have is:

The motor gets hot, almost starts to smoke on 3 cell lipo. Am I going to burn this thing up?
The short answer is YES. If it's getting that hot, you can melt the insulation on the windings or the stator and develop a short. You'll also damage the magnets. In fact, they could already be damaged. When the magnets overheat, they permanently lose a portion of their magnetic strength.

Assuming the motor isn't already toast, try 2S and/or a smaller prop and keep a close watch on the temperature. Sounds like you don't have a wattmeter. If you're going to be winding your own motors, I consider a wattmeter essential.

- Jeff

olmod 02-17-2006 01:11 AM

RE: DIY Motor Turns & Winds
 
Try adding another strand and make it 3 strand and the heat will be less;)

PilotLight 02-17-2006 12:48 PM

RE: DIY Motor Turns & Winds
 
The only reason I didn't go with 3 strands is you get fewer turns. The chart that I found for the Apex 300 motor shows that with a 3 strand motor with 7 to 8 turns, it has a very high Kv and pulls a 4 to 5 inch prop at like 15000 rpm. I was hoping to go with fewer strands with more turns for more torque and lower rpm. Some guys are using thicker wire (.5mm) with about 15 turns so I thought I would use two .3mm strands and get thier results.

No, I don't have a Wattmeter. I looked and looked for some info on fewer strands and couldn't find any so I thought I would try it myself. The idea originally was to copy somebody elses motor set up.

The motor also could be used in a geared setup, but I found it doesn't fit my Great Planes 5.3:1 gearing which has a 370 size brushed motor currently (from a Great Planes Yak 55 EP). Guess I have to experiment.

Thanks for the input.

ron_van_sommeren 02-19-2006 10:53 AM

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

PilotLight 02-19-2006 04:27 PM

RE: DIY Motor Turns & Winds
 
Thanks,

Already read it.

PilotLight 02-19-2006 09:19 PM

RE: DIY Motor Turns & Winds
 
I just tried drilling the firewall mount with ventilation holes to help keep the motor cool. It still heats up with a 3 cell lipo and 8x3.8 prop, so it seems this is too much for it.

Has anybody tried this set up with either a 6x4 prop or running a 2 cell lipo with a 8x3.8 prop?

PilotLight 02-19-2006 09:32 PM

RE: DIY Motor Turns & Winds
 
I think I just found my own answer...

http://www.eflypower.com/modules/new..._id=38&forum=4

Here it is if anybody is interested.


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