solder outrunner from DELTA to STAR to get lower KV

crossbreak

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solder outrunner from DELTA to STAR to get lower KV

This is my EMP 80-100 KV130. I wanna change the KV by factor 1.73 to get KV75.

I know that Lebowski posted some kind of "tutorial" (which is a bit confusing to me) , but I thought I could get there the more simple way because I know the winding scheme.

This is what it looks like with the 6 winding leads seperated. I wonder if I understand the winding diagram right (It should be ABCABCABCABC I guess) then I could just take every second one ond solder them together... couldn't I?
any thoghts though?



c17ff17ysr3svogew.jpg


I would just try if I hadn't just fried my first controller :(
 
your motor is wound-AabBCcaABbcC
you need to find the "starts" of each phase the way lebowski described.

Hey crossbeak, do a favor & count the strands they wound with.


I am pretty shure I ran the parameters wrong when i was figuring out copper volumes in my re-wind thread...
I think i remember 88 strands in total. so 44 "in hand" as they wind the teeth.
please confirm if you get the chance. Thanks in advance.
 
Im thinking of doing this myself, so im defiantly interested in how you go about this...

is it as simple as figuring out which is the -ve and +ve for each winding and connecting the -ves together, using the +ves as each phase?

For example, in the pic in the op, if we go in a clockwise direction lableing each pair Y+Y- B+B- R+R- would you simply join each of the YBR negatives and use each +'ve as phase wires? (ignoring the fact that these aren't the actual positive/negatives for each winding)



looking at lebowski's method for figuring out windings for delta,

Lebowski said:
ok, the clue is to connect everything in a triangle.

Take one winding (lets call this one 1), this is your reference. Spin motor (drill press ?) and measure AC voltage accross this
winding using normal multimeter (in the AC setting !!!!).

Take another winding (2 ?) and connect it to the first one in series. Measure the total series AC voltage. I know it sounds a bit
strange but the total series AC voltage should be equal to the AC voltage of a single winding. If you measure around 1.7 times the
voltage of a single winding then reverse the connections of winding 2 to end up with an AC voltage equal to that of a single winding.

Now connect the third winding (3) in series with 1 and 2 and measure the AC voltage again. If you measure 2 times the voltage
of a single winding, reverse the connections of winding 3. If the total AC voltage of the three series connected windings is 0 then
you've connected everything in the correct order. You can now short the start of winding 1 with the end of winding 3 (remember,
the voltage was 0 so this is no problem).

Now you got your 3 windings connected in delta.
then can we use the same method to find each + and - for each winding? ie in the above example we'd take the 1st wire of each winding and use them as phase wires, and short the 2nd wire of each winding to get wye rather than delta?
 
then can we use the same method to find each + and - for each winding?

Yes. Maybe one could also run a small current through the windings and find out the polarity of the stator field with a magnet. I didn't try both yet.
 
I tried Lebowski's (using a drill and my multimeter in AC-mode) method today, it was pretty easy. The motor runs well now in WYE. I used a 6-Fet sensorless 15amp max current for testing.

We should post Lebowski's method in the wiki section.
 
Now I wanna do it the other way around: Solder a Star Hubmotor (almost all Hubs are Star /WYE) to Delt to gain more speed. Did this with the Crystallite HS3540.

Connected it this way (sorry forgot to take final pic). Hope this help people who wanna do the same.

Runs 97kph no load @ 26.2" and 44.2V
 

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Hello, that's what I did with my 9C clone but I have trouble making it run! it may be the controller but maybe the mod changes the timing of some motors?
 
this is good food crossbreak ! and lebowski

if you convert Y to DELTA, in terms of efficiency is it simply going to be 1,73 faster as if i wouldv winded less turns to give me a 1,73 faster KV, and same toughness on the controller or it would be a tiny bit less efficient or much crazy less efficient (question mark, button broken)

what gauge are your spokes, did you lace yourself ^
 
with some motors, there might be some leaking current that induces eddy current drag when connected in Delta . member Circuit experienced great drag when wiring his Clyte 53xx in delta. In WYE it was fine. I can measure slightly greater no load current consumption with my N6364 motor (for a given RPM), too... need to test it with the Bafang BPM next and of course with the HS3540
 

this is how you can separate the Star connection of the "big block alternative motor" http://www.endless-sphere.com/forums/viewtopic.php?f=28&t=57483#p857304
P1017331.JPG
remove heat shrink of the star connection
P1017333.JPG
search where the wires go into the stator and seperate those three by rods, twist the star point a bit so it starts to open..be carful and dont bend the wires more then necessary..they brake easily
P1017336.JPG
twist further, you can assist by using caliper at the top end
P1017338.JPG
heat the star point with the soldering iron and twist further
P1017340.JPG
done, the first lead is seperated, broceed with the last two.
P1017341.JPG
all three seperated
P1017343.JPG
measure at the three phase connectors if the three coil groups are really separated/open now. You can use your multimeter in diode "beep" mode for that
P1017345.JPG
check which star end belong to which phase
P1017346.JPG
mark them with colored heat shrink or tape
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kink a cable to a star end using copper wire, solder and remove any wire spikes that could puncture insulation
P1017350.JPG
insulate, repeat it with the other two star ends
P1017353.JPG
fasten the cables using cable ties, use at least two or 3
P1017355.JPG
enlargen the cable hole with a file, clean the cover from remaining alloy dust, protect the cables at the hole using duct tape or whatever you want
P1017356.JPG
shorten your star end cables to equal length
View attachment 1
connect it all in Delta, by plugs or solder it or however you want
P1017361.JPG


 
TotallyRadical said:
does it matter which of the 2 sets of 3 cables you short together?
it does not matter which triplet of wires you short and which you use as terminals as long as they are all "starts" or "ends". The trick is to connect the coils in a star topology


TotallyRadical said:
in the thread there was a link to Lebowski's method of figuring out how to wire up Delta, but i can't seem to find out how to apply it
Terminating in WYE means you want more back-EMF voltage than a single coil has. You can use a voltmeter in AC mode to find the "starts" or "ends" while turning the motor with a drill at constant rpm. If you connect two coils in series and measure more voltage than a single coil has, then you connected two of the same kind - i.e. two ends, this is your star connection point (or wye). Otherwise (you measure a lower voltage), flip one coil. Then you just have to do it with the 3rd coil to the star point you just found and you are done
 
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