(Re)winding and building motors, tips & tricks, checks & tests - Page 18 - RC Groups
 This thread is privately moderated by Ron van Sommeren, who may elect to delete unwanted replies.
 Aug 19, 2012, 12:13 PM Registered User i tought so, but im going to rewind turnigy G15 950kV , and im not sure how. it has 22 x probably 32AWG in one strand , and when counting turns while unwinding it, it has 4 , 3.5, 4, 3.5 turns per tooth. Can`t find any information about this motor on the net, can somebody help me what gauge and turns per tooth i could use to get approx the same kV ? im thinking about 24-20AWG. stator diameter is 27mm and length is 28mm.
 Aug 19, 2012, 12:49 PM Registered User Usually, number of turns is "per slot", i.e. a 14-turn motor will have 7 turns per tooth. Have you ever wondered why number of turns are always even numbers? Putting 14 turns on a tooth (for a 14-turn motor) would give a Kv of half the desired value. Don't ask how I know.. Christo
 Aug 19, 2012, 01:12 PM Registered User nope, i never wondered why numbers of turns are alwayz even, because they are actually not. for example scorpion`s motors - S3014-1040 13turns, S3014-1220 11turns, S3026-890 7 turns.. btw, what is slot ? two adjacent teeth in your example? one wire(phase) goes around 4 teeth on 12 pole motor, isn`t it ? im sorry about my beginner`s questions, but i can`t find any info about this numbering. so, in 14T motor, it means 14 turns per tooth, or per slot (two teeth) or per all 4 teeth in one phase ?
 Aug 19, 2012, 01:30 PM Jack delete me... Last edited by jackerbes; Aug 19, 2012 at 08:32 PM.
Aug 19, 2012, 02:07 PM
Registered User
Quote:
 Originally Posted by xener nope, i never wondered why numbers of turns are alwayz even, because they are actually not. for example scorpion`s motors - S3014-1040 13turns, S3014-1220 11turns, S3026-890 7 turns.. btw, what is slot ? two adjacent teeth in your example? one wire(phase) goes around 4 teeth on 12 pole motor, isn`t it ? im sorry about my beginner`s questions, but i can`t find any info about this numbering. so, in 14T motor, it means 14 turns per tooth, or per slot (two teeth) or per all 4 teeth in one phase ?
Sorry, I was referring to the older version Scorpion motors, not version-II. Look at this page. All the motors are even-numbered. Obviously, Scorpion are now doing LRK-winds, where only every alternate tooth is wound and therefore the full turn-count can be put on one tooth. Can someone please confirm this.

LRK winds are not very common these days and I have never seen any Turnigy motors being wound this way. Most outrunners are wound dLRK or "distributed LRK" where every tooth is wound with half of the turns of the turn-count.

Yes, slot means the valley between teeth.

Christo
 Aug 19, 2012, 02:57 PM Registered User thank you both for answers to my doubts. original G15 is dlrk, delta , now im thinking about star with one wire if it would be possible, Im going to check some conversion tables to check what i can do. Some kV up is not a problem, its a motor for WWII plane. S3014-1040 V2 is running in my Katana S30, and every tooth is wound, its not LRK. But seems like not every manufacturer count turns the same.
 Aug 19, 2012, 03:39 PM Jack delete me... Last edited by jackerbes; Aug 19, 2012 at 08:33 PM.
 Aug 19, 2012, 04:35 PM Registered User my apologies , this is my new thread: https://www.rcgroups.com/forums/show....php?t=1715068 jack, please move your valuable posts there, please. and of course, i would like to ask thread owner to delete my posts, please.
Aug 19, 2012, 04:49 PM
Registered User
Quote:
 Originally Posted by xener S3014-1040 V2 is running in my Katana S30, and every tooth is wound, its not LRK. But seems like not every manufacturer count turns the same.
Interesting. I know for a fact that Scorpion counts winds per slot and not per tooth, because I've wound some Scorpion kits to factory spec and confirmed this myself.

If they do 13 winds on the S3014-1040 V2 motor, then they must have found a way to do half turns per tooth. I've thought about it before, but never tried it myself. "Half turns" will give you more Kv possibilities. It's a great idea if it can be done.

Christo
 Aug 23, 2012, 06:56 AM Registered User hello again, i have one more question, if i can`t fit two 20AWG wires , can i use combination of one 20AWG+one 21AWG ?
Aug 23, 2012, 07:08 AM
Registered User
Quote:
 Originally Posted by xener hello again, i have one more question, if i can`t fit two 20AWG wires , can i use combination of one 20AWG+one 21AWG ?
Yes, I've mixed wire gauges many times. However, there are people who will tell you that you shouldn't do it. It works for me.
Christo
Aug 23, 2012, 10:20 AM
Jack
Like Skylar says, that will work fine.

As long as the two strands are soldered together at the ends you have sum of the resistance of the two wires in parallel. We don't really care what the value of that is, it is just that the more copper there is in the phase the lower the resistance will be and the higher the current can go.

We were joking around about it once and I designed a closer to perfect wind, it would be made with large and small wires with each succeeding smaller wire being sized to fill the gap left by the previous wires. Each strand would have three wires in my design, you can see a cross section of it in the image. No one does actually does that of course, can you imagine trying to keep all that in place as you worked?

And, did you know, there is such a thing as square motor winding wire so as to leave less unused space?

Jack

### Images

 Aug 23, 2012, 11:23 AM low tech high tech Hexagonal might work. Closer to round, easier corners.
Oct 31, 2012, 11:57 AM
homo ludens modellisticus
Permanent Magnet Motor Simulator
Emetor: a PMSM design tool

Uit
groups.yahoo.com/group/lrk-torquemax/message/13495
Quote:
 ... Here you can start doing some basic design end start to get the right skill to understand how motor works. Of course is a generic software so is not 100% correct , once you get very close to the physical limit the granularity of FEM (Finite Element Model) create some artifacts and deviance form the real world so get ready to have at least a 5% difference between the model and the real motor. ...
en.wikipedia.org/wiki/Finite_element_method

Vriendelijke groeten Ron
Nov 01, 2012, 02:52 PM
Duh
Quote:
 Originally Posted by Skylar Crashawk I can't agree with your statements above. It IS amps that causes a motor to heat up and burn the windings. Look carefully at this formula: R x IČ = copper loss. R (or Rm) is the resistance in one phase of an outrunner motor. So, amps squared times the Rm is what causes the primary loss in a motor, i.e. the main source of heat. In outrunners, iron loss is usually much smaller than copper loss and can also be calculated: Io x volts, where Io is the no-load current. Christo
most people around here can't use formulas, it's easier to remember what the max watts recomended by the manufacturer is, and most have a max wattage, not max amps since if they rated it at x amps for say, 2 cells someone would try to run it at the same amps on 4 cells and very quickly burn it up. it's all in the watts. lol.

either way you look at it though, I still recomend a meter if you are going to experiment. a good way to measure the temp of the stator is a good idea too if you are really going to push it.

Jason