Rewinding a Turnigy 80-100

[drewjet]

I finally got my 80-100 130KV motor. I hooked up the ESC and sure enough it works. Now to improve it.

This is intended for my Electrathon racer which currently has an original Etek brushed motor in it. Currently I can go about 30 MPH on around 1000 watts. I want better. If you don't know about Electrathons, in a nutshell it is a 3 or 4 wheeled electric vehicle that is raced to see who can go the furthest in 1 hour on 1KWH of batteries.

My calculations say that I need a KV of about 90. This is calculated from running a 20" tire 48 volts and using a 12 tooth sprocket up front and a 92 to 98 tooth extron on the wheel single reduction. Since I am pulling an average of 1000 watts, I don't believe the lower Kv will hurt me as I don't want or need max power out of this motor.

View attachment Turnigy2.jpg

Fill is OK, but could be better

View attachment 1

It is mrked Y8 with a sharpie, I confirmed it is 8 turns, but it is connected Delta



I am guessing that I need 11 turns to put me in the ballpark. I only need to be close as I can change gearing within reason to get the speed I want. Anyone care to confirm?

 

[liveforphysics]

If you're looking for every last bit of efficiency, a little more RPM will help you get there, but if it means adding a second-stage reduction, it's not going to be worth the additional mechanical losses. If you're building it for an event though, I would go with an 8T sprocket, and jump the KV up 50% or so. The noise of the increased chordal motion and increased rate of chain wear wont matter for a race machine, but that extra efficiency will let you squeeze a bit higher average power to that rear wheel.

Also, if you don't mind the hassle of making the connections inside the motor, terminate in wye, and minimize recirculating currents for a freebie ~1% efficiency (maybe even more at these lower power levels).

 

[Thud]

drewjet,
do you have a link to your electrathon organization? I allways thought it would be fun to get a team together.

seems everyone is re-winding 80-100's these days :lol:

 

[liveforphysics]

seems everyone is re-winding 80-100's these days :lol:

They left room for so much more copper in there! Too tempting not to do.

 

[drewjet]

drewjet,
do you have a link to your electrathon organization? I allways thought it would be fun to get a team together.

seems everyone is re-winding 80-100's these days :lol:

http://www.electrathonamerica.org/Welcome_to_Electrathon_America.html

Me and my buddy built ours last year, we went to 5 races and won them all. It is a blast. I really need to do a build thread (after the fact) on it.

I just wanted to get on the band wagon. I have probably wound or rewound over 100 outrunners, but by far this is the biggest ever for me. Before this was the Turnigy SK 63-74. This thing dwarfs that.

 

[drewjet]

Claened and ready to rewind.

Damn you LFP for making me rethink my simple stratigy.



10.9 ozs of wire removed

 

[Thud]

Thanks,
Been awhile since checking that sight, I see they have some new battery classes. very cool.
what kind of distances are you guys posting? This has allways looked like a lot of fun to me.

Now the big Q. what are you re-winding with? (I am using 14 awg & by all acounts I am getting almost twice the usable amount of copper onto the stator) & acoriding to the motor calculator, We should be able to do even better than that.

Also can you confirm the stock strand count? I counted 98 strands last night of .007"dia (33awg) on an older version of the 80-100.

I am so tempted to drop the kv on my motors & jam the voltages up...but thats not for electrathons.
I also have a simple brake dyno on line for testing...I really want to hear how these are turning out.

edit: are you planing on getting the bearing tube out befor rewinging? I doubt i could make the conections without removin it.....but I am a ham fisted hack on my best day.

 

[drewjet]

I didn't count individual strands, and I didn't really try to save in a way that i could. I am going to use 25g wire. I have not had good success using thick wire. I find it too hard to make the turns and keep it tight.

My local electrathon website is http://electrathonoftampabay.org They are based in Tampa about a 90 minute drive for me. My next race is on 9/11/10. i am not sure if it will be ready by then or not. Besides the rewind I am waiting on Gwhy to make me a set of sensors and also the shaft adapter from you (no rush).

I used lipo for the first time in the last race. I used 8 of the 6S 5000 MAH 20C wired as 12S4P. It already handled well with the optima Yellow tops, take 58 lbs out of the car and WOW!

With your skills I am sure a badass Electrathon would show up. DO IT!!!

 

[liveforphysics]

I am going to use 25g wire. I have not had good success using thick wire. I find it too hard to make the turns and keep it tight.

The trick is a firm plastic stick. I like to use a cut-down section of an old RC prop. Lay the wire in there, mash it down with the RC prop nice and neat, then use the tip of the prop with tiny notch cut in it as a tool to round the corner tightly and back into the other side of the slot. It's fatiguing on the fingers, like 10x more fatiguing than doing the smaller wire that just lays flat when you give it a tug, but, it also is very easy to get the fill all stacked perfect with no accidental crossing/overlapping stuff. And less space is used for insulation rather than copper.

But... anything can do a really fine job, and in this situation, the heat rating of the insulation isn't even a factor, which means you can run the really non-brittle enamel types to make it go even nicer.

 

[drewjet]

I already have the wire, I believe it is the enamal style. i knew that this motor won't be running hot.

I already use the prop trick. I also tie the wires to a doorknob and just stand and work my way to the end. It is much easier on the hands pulling on the stator and not trying to pull on little wires.

I thought some more about your ideas. I think the smallest sprocket that I can get in the 219 is 12, plus I already have it. I also think I want the delta wye switching as that way at the end of the race when batteries are near empty I can get more out of it.

Can anybody confirm my 11 turn should give me 90 KV theory????

 

[Thud]

Jeremy Harris just posted this in the motor section thread.
the #s are based on the 80-100 stator dimensions
http://endless-sphere.com/forums/viewtopic.php?f=30&t=20608&start=15

 

[olaf-lampe]

Hi Drewjet,
do you mind to measure the winding area for us? I also asked Thud, but twice is better

I like to spend my time thinking about the wiring, till the 'naked' colossus' arrive.
Many thanks
Olaf

 

[Jay64]

Drewjet, I haven't heard from you pretty much since the battery beach burnout we met at last time. Good to hear that you jumped into the elctrathon stuff. Where is your 9-11 race going to be at?

 

[drewjet]

Jay, It is at
Tampa Bay tech
6410 Orient Rd
Tampa, FL 33610-9438

This is near the intersection of I-4 and I-75

Not sure on times, but usually the first race is around 11AM and the second is at 2 PM

 

[Jay64]

If I'm off from work that day I'll try to make it up there. I wanna check out your build. Good luck.

 

[drewjet]

Jay, I hope to see you there. but if not there is one about every month in the area through May.

Let the rewinding begin. First I took the wire I bought 3 lbs of #25 and wound 2 adjacent teeth to calculate how much wire I needed. I was able to get 360 turns between the 2 teeth, I settled on 7 turns per tooth so I ended up using 26 strands (7X2X26=364)



Man that is a lot of winding





From my 3 lb wire spool and the wire I snipped off I have almost exactly 2 lbs left, therefore I put 1lb (16 ozs) into the motor minus the 11 ozs previous means I added 5 ozs of copper. Hmm, not as good as Thud, but still I am happy, and this is for a motor that will probably never see more than 25oo watts and an average of more like 1000 watts.

I have a keyed shaft and new bearings coming soon, so I didn't want to put it together permanently, but I did slap it together enough to run. Nice and smooth and drawing 1.97 amps on 24 volts. So far so good.

 

[dbaker]

From the perspective of an experienced rewinder like your self, how long did it take you once you determined the winding method?

 

[drewjet]

I didn't time it, but the A Phase took maybe 15 minutes, It is the easiest as the first and third tooth don't have windings on either side, B phase about the same, c phase is a bitch and took about 45 minutes. Of course this is made all the tougher by being done in my sweat shop (Central Florida in a garage with no A/C). I did it in my garage as I wanted to use the vise to hold the wire and wind the stator to it and be able to pull on the stator real hard to get the windings as tight as possible. I think I may try like Thud next...if there is a next time and use thicker wire and less number of strands.

 

[dbaker]

And you did this without removing the bearing tube The only purpose of the garage vise was securing the wire end. Maybe do that to a door jamb, exercise machine or countertop with AC inside.

 

[drewjet]

As hard as I needed to pull, I was afraid of tearing up something in the house.

On smaller motors I usually use a doorknob.