smaller multi strands versus larger single strand

[dougk]

6 strands/6 winds 22.7mm double stator using 24each 10X3X2 n50 mags arranged NNSSNN (little to no space between any two mags) with a 3 cell lithium will turn a 4.75X4.75 APC prop 21k rpm in the 13.5 amp/130 watt range...motor not even warm.

Does this sound correct? I dont see anyone winding these quite this hot. Anyone else winding these with less than 9 or 10 winds?

Second question. What kind of limits are people finding with double stators? At 13.5 amps, motor was cool to the touch (WOT for approx 1 to 2 minutes). I even backed it off to the 10 amp range and ran it for another 3 or 4 minutes. Still cool to the touch.

Since I have no use for this motor (at this time), tomorrow I will try some 5,6,7 inch props and push this up to the 15-17 amp range.

Any input on hot winds/multi-strand configurations would be appreciated.

Doug K

[ron_van_sommeren]

Instead of thick wire you can use several wires in parallel to make winding easier. That's all, it's a production advantage. It has nothing to do with eddy currents or more copper.

[Air Mover]

Not true 3strands of 26g is like 16.5g
2strands 24g acts like 18g

try winding a 7T with 16g waste of time
7T 3X 26g not a waste of time
same with 18g wire ..

more copper faster amps / voltage flow....always a benefit for those who want rpm with plenty of mags.. 6mag motors are a waste of time and performance.. 8/10/12 mag motors always better power per amp...to keep the rpm up you must open up the wire size in our case multi strands are better .most the stators we use are small cant really handle anything more then 22g without wasting alot of space.... tighter copper fill per tooth less gaps... always benefits always!.. I dont like thin wire past 28g tops as its easy to break/fail

[swatson144]

Not true 3strands of 26g is like 16.5g
2strands 24g acts like 18g

try winding a 7T with 16g waste of time
7T 3X 26g not a waste of time
same with 18g wire ..

more copper faster amps / voltage flow....always a benefit for those who want rpm with plenty of mags.. 6mag motors are a waste of time and performance.. 8/10/12 mag motors always better power per amp...to keep the rpm up you must open up the wire size in our case multi strands are better .most the stators we use are small cant really handle anything more then 22g without wasting alot of space.... tighter copper fill per tooth less gaps... always benefits always!.. I dont like thin wire past 28g tops as its easy to break/fail

It is true! hmm let's see. ron_van_sommeren said it was a "it's a production advantage" I'd have to agree. If you want 7T 16g and don't want to buy square wire you could probably fit it in multi strand. That'd be a production advantage? So one raises the question why pick nits and then make blanket general statements? 6 magnetic pole motors are certainly a use to someone, though I agree that I also have no use for them at this time. Tighter copper fills are always better? Why? I find that most of my planes fly in the very nicely in the 18t 24g area. I have no problem wrapping that with a single strand. so I don't need a "it's a production advantage" for that application. YMMV. I don't want additional increased current but I don't compete. I also find that if I want the motor to act as if it had fewer winds I just terminate delta. BTW amps don't get faster no matter what. Voltage NEVER flows.

[Air Mover]

I know for a fact through actual use..that multistrands radius copper wire.. can fill a stator better then larger single dia winds..and improve the motors ability to absorb more current ...I know for a fact that delta isnt the cure for low rpm nor less mags..Once was a high voltage powerlineman 15yrs.. we would put capacitor banks online to stop current from lagging voltage.. the real solution is to upgrade the lines to a larger dia wire..but that costs.. another solution was to up the voltage to reduce the amps but that costs as secondary distrabution ie stepdown transformers have tobe replaced with diffrent winds to convert the higher voltages...current can lead voltage too..yesss!!!! not as common but does happen... voltage and wire size controls the rate of current flow possible the stators iron and all mech factors put aside.

lets say you wanted a 3d motor.. with reasonble rpms to fly well above stall... whats better a 19t 26g(acts like26g) wye 12mag motor
or a 19T 2strand 28g(acts like 22g) wye 12mag motor..?

answer..the one with more copper fill and better voltage and current flow...less chance of warming up ....
IF the stator isnt saturated but the copper is hot becuase its undersized for the load placed, your going to drop volts raise amps/ heat up and loose rpm and run time...even if the motor is only warm and your happy you still didnt get the most out of the motor..you gave up some performance with a single strand unless its small gage wire sub 28g..we are all limited on what we can do to improve performance...


Fact through actual use.... you can increase rpm by having more copper as it allows the electrons to flow freely less lag this will increase performance!!!!!!!!!!!
ron_van_sommeren said it was a "it's a production advantage" sure it maybe but we all know the real advantage is configurations that only require one single strand thats the easy way....
the motor makers know they have to handle the amps.. somehow...or they wont sell motors...Ron stated no other advantage..thats the part that gets my feathers up..as I have gone through real use tests..tit for tat back to back tests..in the air and with rc boats... blanket statements//// as I dont have time to spell it all out..just like Ron is limited in time.

like Ron .. we both enjoy sharing what we learn//I share what I have done personaly ... seen with my own eyes...more so then whats just read.

You stated...
So one raises the question why pick nits and then make blanket general statements? 6 magnetic pole motors are certainly a use to someone, though I agree that I also have no use for them at this time. Tighter copper fills are always better? Why? I find that most of my planes fly in the very nicely in the 18t 24g area. I have no problem wrapping that with a single strand. so I don't need a "it's a production advantage" for that application. YMMV. I don't want additional increased current but I don't compete. I also find that if I want the motor to act as if it had fewer winds I just terminate delta. BTW amps don't get faster no matter what. Voltage NEVER flows.

Yes 6poles are ok but not the best way..fixes are double up on mags 2X6pole setups help increase torque to lower amps..but this also takes away some rpm....I found through real world use that my 8mag motors fly faster 4:1 ratio as a single stator. 108mph vs 120mph plus..why due to limitations in drag and all up weight of a micro on a single stator...when you reach the top end.. of a 10amp esc you learn how to improve without nuking the controler...

Mags are the free power source always use them to the max.
Most cant wind 18t 24g..if you can then wonderful.!!!!!!
I can stack two neat rows 15T for a single stock' no rubbing on the wires .. with the GBX frames you can plump them up further...

Higher the voltage faster rpm/no load... put aload on it and the heat climbs..if the wire cant handle the amps/and stator iron.
higher the amps the more torque you can produce to maintain some of the rpm produce by the higher voltages.

you said...
I find that most of my planes fly in the very nicely in the 18t 24g area. I have no problem wrapping that with a single strand. so I don't need a "it's a production advantage" for that application. YMMV. I don't want additional increased current but I don't compete.

try 2strands of 26g 18T...acts like 20g vs your 24g
advantage: motor draws less amps/ resistance/heat..you get higher rpm...if the prop loads have the 24g ...try it and see for yourself.

motor building goals are to get the best possible always...if not then your not treating yourself or your gear to the advantages...
in time you will, as nothing is ever perfect once your aware of your losses.

When amps lag the voltage the wire gets hot... need them balanced to keep things cool as possible..if the river banks are flooded you get heat..each type of metal has a given amount of electron flow based on type and size ....
When voltage lags the current... wire gage is too big and its sucking down the voltage needed to move free electrons within the conductor...
I have found I can reduce a turn or two.. up the cycle speed per phase.
neat little trick unknown to many.

Remeber if you want a real results to anything you need to find out by doing...just reading about it has limitations.

:idea:

[swatson144]

Well sir with the concerns you have, you may want to look into www.mwswire.com. They have microsquare wire that would allow one to wind with very little air left in the stator. It's available in various builds and sizes. They also make flat and twisted multi strand though I don't know how that would help as winding multiple individual strands isn't difficult. Just visit some small rewind shops and bring a motor with you for show and tell and odds are very good you'll walk away with some free wire to use, though it is hard to find anyone using the square.

[ron_van_sommeren]

Imagine a stack of pipes (wire), neatly stacked so they occupy the least space. Most people think that by reducing the diameter of the pipes, the space between the pipes will decrease. This is not the case, no matter the diameter of the pipes (wire gauge), the space will always by 10%.

Now, in a multilayered coil the wires are not stacked like pipes but the reasoning is the same.

[latrans]

Ron,

That is true, the 10% dead space, but when you're working in an area of limited space, between stator arms, you will be able to squeeze more of the smaller wire into the narrow gaps than you could with the larger wire. To put it another way, the 10% dead space is arguement is only relevent if the the total space to fill is is a whole integer of the larger diameter pipe. If the larger pipe has a diameter of X and the smaller a diameter of Y(which we will arbitrarily assign the values of 10 and 5 respectively) and the space to be filled is Z (which will assign the value of 25) then you can see that with the larger wire you have 20% of your total space unfilled (2 layers of pipe X while with the smaller pipe you can have 5 layers. The difference is 2x10=20 (for the larger pipe) vs. 5x5=25 (for the smaller pipe. The net difference is 20% more pipe, or wire, can be used if the smaller of the two is chosen, this is called stacking efficiency.

I don't honestly remeber what the point of this thread was but (I think) my point is that in certain circumstances winding with multistrand wire of a smaller size does have definite advantages.

Really I just wanted an excuse to bust out a little arithmatic on Ron :wink: .

Latrans

[ron_van_sommeren]

Yes, my method does not take 'boundary effects' into consideration.

[thunderstreak]

Yeah! Yeah! Yeah!

So for the real deal, does anyone have a chart equating different multi-strands to single strands for winding?
Thanks,

[thunderstreak]

Ok,

No one has a chart. :?

How about a formula?

How are you equating single strand to double strand?

Equal area of the gauge? :roll:

I don't know! :oops:

If anyone has answers I'll create the chart. :wink:

[swatson144]

I use this chart since it has cross sectional area. If you already know the max # of turns of 26 AWG you are comfortable with it gets pretty simple from there.

http://www.dave-cushman.net/elect/wiregauge.html

ie The max turns of 26 AWG I am comfortable with is 20t YMMV.
20x .1297= 2.594mm2

so how many turns am I gonna be OK with for 28 awg
2.594/.0805=32t so I can fit 32 or 16t 2x or 4t 8x etc.

Don't push too hard against the boundries as it doesn't consider that the insulation is getting multiplied along with the copper. The only accurate way to do this would be to have the mm2 of the wire and insulation, information that hasn't been made available to us AFAIK concerning the GB double build wire.

[thunderstreak]

Hello All,
:D

I said I would post a chart, and Here it is. :P

Look this over and tell me what you think.

Sheet one has my calculations on it.

Sheet two has wire gauges in order (by cross sectional area).

Including single, double, & triple strands. :shock:

Enjoy! :D

BTW this is an excel file