12-01-2009, 12:00 AM
hi all i am in the middle of rewinding an axi 2208-34 to get a higher kv to spin an apc 5.7x3 prop. i have been looking at some of the scorpion winds and found one i would like to try being a 12t delta with 7 strands of 30awg wire but it is on a 2212 stator. how do you think that this wind would work on a 2208 stator. also which would be easier to wind standard lrk or dlrk. also what would be a better wire to use 7 strands of 30awg is kinda tough to work with i tried it once already but it shorted to the stator so i took it all back off. thanks for your help
12-01-2009, 01:57 PM
rotccapt – I too am in the middle of an AXI rewind. Btw, how did you get the old windings off? I had to cut mine with a Dremel, then pick and scrape.
Back to your question…
An LRK wind is much easier than a dLRK wind, but I’m not sure you can get that many turns onto one tooth. I have only done a couple of dLRK winds (the rest have been simple ABC’s), so I am not sure if the 12 turn dLRK wind is 6 turns of 7-strand per pair of stator teeth or 12 turns of 7-strand on each tooth (both being 30Ga).
Reason I say this is that 7-strands of 30 Ga is about the same as 1-strand of 21 Ga wire. Using almost all the winding tricks in my bag, I can just get 12 turns per tooth of 22Ga on a 2408 stator, so getting 12 turns per tooth of 21Ga on a 2208 stator, in my opinion, would be next to impossible. So my guess is that they used 6 turns per tooth in each dLRK pair.
That said, using the same number of turns on a thinner stator (your 8mm vs the Scorpion 12mm) results in a higher kV than the thicker stator. I am not sure if the increase is linear, but should be close.
What you need to figure out is how fast do you want to spin a 5.7x3 prop and at what current draw. From there, you can work backward to figure out what kV you need to wind to. Just out of curiosity, what are you putting this into? Please let us know your goals as far as pitchspeed and current draw and we would all be happy to help.
PM me your email address and I will email you my Multi-Strand wire guage conversion calculator. It very handy in figuring out what single strand guage is equal or better to any original multi-strand wind. It also gives you the overall difference in resistance (lower is better).
12-01-2009, 02:26 PM
Just so you or anyone else doesn't have to divulge email addresses, below is a zipped version of the Excel Multi-Strand Conversion Calculator.
12-01-2009, 11:30 PM
thanks for the info this motor will be going on a 40" flying wing that weighs 17 oz. my amp cap is 30 amps because that is my highest amp esc that i have. as far as pitch speed i would like to be some where in the 80 mph range if needed i could change to a different prop maybe a graupner 6x6 cam prop. thanks for that calculator it will come in handy.
12-02-2009, 05:39 AM
well i did some test winds today and i can just get 13 winds on a tooth using 22awg wire lrk so i think i will try that. i am thinking the extra wind should drop the kv down a tad hopefully making up the difference in the added kv of the smaller stator thickness how does that sound? i will have to take my time and do lots of squishing as i go but it did turn out very neat looking. i did only wind one pole but since it will be lrk it would not matter any way. also i can do the same wind dlrk too with the 22 awg. what so you think?
12-02-2009, 01:34 PM
rotccapt - from what I understand, there really isnt any real resultant difference between LRK and dLRK, so if you feel more comfortable with LRK I say go for it. Besides, dLRK requires you to watch winding direction closely and stay on top counting the turns.
If you really want to know the outcome before you do the final 'real' wind, do a sloppy test wind with cheap small guage wire and test the resulting kV using the power tool method. Then you will KNOW how to scale the winds to get the kV you want.
12-04-2009, 02:03 PM
rotccapt - well, the numbers look correct so you should be good with that. Just be sure to order the magnet spacing alignment tool - it is worth its weight in gold when it comes to glueing magnets. double check polarity on the mags too.
the only thing that really stood out when looking at their data, was when they started getting up to your level of kV, all of the charts were using 2S packs. I didnt see any 3S test data. you may want to get onto their forum and be sure that those motors can take that kind of abuse. I know that 24x8mm stators can. I just dont want you to burn up a good set of magnets.
since you are willing to go the GB route, why not just make your AXI a 3000kV motor to test? if you burn it up, then you still have the GB kit to turn to. to get 3100kV from your AXI you will need to make it a 2208/12, so wind it with...
6 turns per tooth dLRK (or 12 turns every other tooth LRK) terminated 'Delta'
OR 7 turns every other tooth LRK terminated 'Wye'. to do a 'Wye' in a dLRK, you would need an asymmetrical 3.5 turns per tooth (4turns on one of the pair then 3 on the other part of the pair).
I say, wind up the AXI while you wait for the GB kit to arrive. Please let us know how it turns out.
12-04-2009, 04:46 PM
well i actually already have the gbx single all i have to do is change props. i already had this motor wound. also a gbx-1 kit can take 3s lipo i have been using this settup for a few flights but with the 5.7x3 prop. with this settup the motor bat and esc are all cool to the touch after flying a hole pack threw at full throttle
oh and yes the magnet spacer is awsome
12-04-2009, 05:41 PM
cool! then your good to go and you have a motor you can make a low kV with. or, wind up the AXI to match and see which one you like better.