Delta vs Wye winding

[2moto]

Looking at using an outrunner motor for a new project. Size-wise, one of these would fit nicely:

Specs (as far as they go) are here: http://www.hobbyking.com/hobbyking/store/__18184__Turnigy_Aerodrive_SK3_6374_149kv_Brushless_Outrunner_Motor.html

Now, I'd like a even lower KV than the 149V/RPM that this motor provides. I've read that if you can convert from delta to wye winding, it will lower the KV by the square root of 3, i.e. 86V/RPM. Is this possible on these motors? I presume much of these type of outrunner motors are pretty similar. Are they likely delta wound as standard? I suppose the centre tap doesn't get connected externally.

Cheers.

 

[mlt34]

most outrunners are the opposite of hubmotors, meaning they come wound as delta. You can certainly rewind them to wye, but you'll have to consider how much space you have. I believe that one reason the outrunners are wound in delta to begin with is to avoid having the tail from wye becoming an interference problem in the small can.

 

[mwkeefer]

You don't need to rewind to convert from Delta to Wye, merely reterminate the motor as wye or delta.

Delta termination is what your RC outrunner comes terminated as already... The effect is 1.73 : 1 increase or reduction in kV and a subsequent increase or reduction in kT (wye seems a bit more efficient in general).

Your motor is kV stock as 149 so yes 86 is on target for retermination which would give you a kT of 15.7325 in oz per Amp.

Hope this helps!

 

[2moto]

Many thanks for confirming this. I think I'll take a punt on one of these, open it up and see if there is room to re-terminate it. Is re-termintation pretty much possible on any motor? Or, can it be that the wires are "buried" and not easily accessible?

 

[mwkeefer]

While phase lines can be oddly terminated, perhaps too short to extend without some real work, etc... Normally they are fairly simple to adapt from one to another termination type. I've personally done it on a few motors, many others in the forum have done it even on Hobby King motors and had good results.

Just search for Delta / Wye BLDC termination - there should be plenty of material out there covering the bases.

Hope it helps.

 

[2moto]

That sure helps, thanks. I peruse the forum for more details.

 

[Hummina Shadeeba]

I haven't done a retermi action yet but likely will have to go from delta to wye since my gearing is 1:1 on a skateboard. Typically with the same motor people would use a 2:1 gear

After taking one tacon160 apart looking I reterminate it I found somehow both the starts and ends were buried. People said I'd be able to get them out but they weren't budgin and they weren't rven covered by a layer if epoxy. I have another tacon 160...can't I reterminate outside the motor going from strand to strand finding a curcuit and then making my pigtail with all the ends...outside the motor?! Maybe simply use a battery and led? Or would an ohm meter be safer? In my mind this seems very doable but I've never heard of anyone doing it. Someone at rcgroups told me
It would be possible. If it doesn't work I imagine I'd be ale to re-shrink wrap
My initial 3 motor leads