Dynamite 3835 1500Kv

[TRUCKPULL]

Don

Have you had the opportunity yet to look at a Dynamite 3831 - 6 pole 2000kv - 1.5D

Larry

[donhuff]

Yes I have Larry

[Speed3]

KV has to do with total turns.

Example a 12 slot 4pole that have 2y of winding has 24 total turns. If that motor have a 30mm rotor and it kV is 3000 rpm/v.

A 6 pole 18 slot motor that have a 2y winding configuration have 36 total turns. Let say this motor have a 30mm rotor it kV will be 2000 rpm/v if its rotor has the same total strength as the 4 pole motor above.

So 24 total turns gives 3000kv and 36 total turns give 2000kv.

You might notice a 2 pole would have significantly more turns to have the same kV as the 4 pole and 6 pole.

That is because it only have 3 slots. So it would take a 12 turn to get 2000kv with a 30mm rotor in the above cases.

[donhuff]

Speed,
I'm not sure of what your getting at there, with your turn count. This sounds more like an outrunner as they DO typically wrap the wire around each tooth individually. Most (but not all) inrunners do NOT do that, and instead wrap each "turn" around three teeth per turn, to make up one coil. If you take one strand of wire, from one leg, and run it through a 4 pole motor. It will go through only 4 slots before getting to it's other end.

The term "turns" refers to the number of times the wire bundle goes around a set of stator teeth, to make a coil.Then in a 4 pole there will be 2 "coils" per leg, and three legs (phase) so 6 coils for that motor. And with a 6 pole you have 3 coils per leg and 9 coils total.


I Wondered if there might be something to you total turn count vs kv idea so I went to the Lehner website and looked at the 1930 which seems to be the closest thing they have to the motors that we are discussing here. And a 12 turn like you suggested has a kv of 1742, that's pretty close but that is with a delta termination. Convert that to wye like the other motors were talking about, and you get 1005 kv.

To give you some food for thought. Kv is the point where a motor is "Making" as much voltage (back EMF), as you are putting in to it. That's why at peak unloaded RPM the motor has NO torque and thus NO horsepower.

[ray schrauwen]

Awesome day at brushless motor school.

Thanks Don.

[donhuff]

I have a bunch of stuff ready to take to the race this weekend. I'll show it and explain what I'm doing to anyone that's interested.


Notice in the picture that there are some papers with a stator drawn on them and the windings drawn in with three different colors. See also there are some sheets without the wires drawn. These are the "test sheets" so I can see if your listening or not. I told you there would be a test!


I also have an AQ motor that we can wire and run if we have time.

DSC_5798.jpg

[TRUCKPULL]

I wish I could be there, even without racing.
I could sit all weekend and learn how to wrap stators for brushless motors.
I use to do my own motors back in the brushed days, (slot cars)

Larry

[donhuff]

Don't know that I will have a lot of time to show it all during the race days. We are very busy usually racing, mechanicing, and helping with the retrieve boat. I should have a little more time this year as only two of my sons will be there racing, and the wife is not racing either.

Back in 1967 I rewound a couple of my slot car motors. I was 14 years old at that time, so they didn't turn out very pretty, but they did run ok best I remember. I remember shimming the magnets in with black electrical tape too.

[trigger]

Don, can you school us at the MI cup too. Mike and I will be there again and would love to be schooled over a beer or three.

[donhuff]

Sure, and maybe I'll be learned sumthing else by then.

only three??? You know I talk even slower the more beer I drink. How much time do you have?

[Doug Smock]

[ray schrauwen]

I have a bunch of stuff ready to take to the race this weekend. I'll show it and explain what I'm doing to anyone that's interested.


Notice in the picture that there are some papers with a stator drawn on them and the windings drawn in with three different colors. See also there are some sheets without the wires drawn. These are the "test sheets" so I can see if your listening or not. I told you there would be a test!


I also have an AQ motor that we can wire and run if we have time.

[ATTACH=CONFIG]158723[/ATTACH]

You already soldered the wires for the windings. I thought that was done last.

Somebody video tape it and put it on YouTube or FB.

Are the green things actual stacks of stators? They almost look like plastic practicing formers.

[trigger]

Ha funny, Mike talks faster after a few beers, you talk slower, overall time will be unaffected.

[donhuff]

Yes Ray, the wires are soldered first at the "Y" connection. With the insulation being so hard to get off, and needing to be dunked in the molten lye solution, this would be to hard to do and keep short so you can bend it enough and keep it inside the back of the can.

By soldering the Y first, you can pull it down tight to the stator and lay it over sideways, and that is the very first step in the actual winding operation on a Y. On a Delta, you can leave the "start" end of the wires as is, and then strip and solder when finished along with the "finish" end wires. But you'll still need the needle.

Your probably also meaning that the wire bundles where they will be coming out of the motor, are soldered too. I do that to make a rigid "needle" to use while sewing the bundles through the slots. You can do it without soldering first if you use a very low wire count, and there is lots of room left over in the slots so that the wires go through easier. You can also use Ca glue on the wires to form a needle, and get decent results. But again if your packing the slots full, you will have a hard time getting them through the slots ON THE LAST TURN, loose wires will make a big mess and the ca needle usually breaks. It's aggravating and a waste but making the soldered needle but it is the best way I have found to do it. Also, it sometimes helps to put a slight bend in the tip of the needle, to make the point go to a corner of the slot and follow that corner, so it exits where you want it to and not pass through the middle of the wire already in the slot.

After completing the winding, then you cut the lead wires and needles off to as long as you like, and resolder.


Yes those are plastic stators. I have a friend with a 3d printer and he made those for me. They work great for practicing and demonstrating, and they don't scratch the insulation on the wire. If you thread the wires through a real stator very much. You'll end up chipping the insulation on it, and you don't want to do that more than you have to. When unwinding a stator, it's almost impossible to get all the wire out without chipping it a few times. I sure wish I had a solvent that worked.

[ray schrauwen]

Wow, awesome!!

A new question. I just received a chinesium motor from Fleabay. It's a $26 special. Can says 36mm x 70mm but you can dance in the front plate space.

Lets say I want to shorten the can to say 60mm, how can I shift the field coil since it's glued in? I wanted to trim the can down on my lathe to fit speccy classes.

It's possible to just machine it down but the front plate mounting screws might be real close...

2280kv and it's a Y wind. I don't know how accurate the 2280kv is.