View Full Version : Rewinding a HobbyCity FC28-22
03-21-2009, 06:21 AM
I bought this just to rewind since I have so much fun with the FC28-05 rewind from a couple years back.
I'd like to wind this for parkjets too, small ones are my norm.
I tested the motor with a 1200rpm drill and got .83vAC.
So the motor is roughly 966kv. It's advertised KV is 1200.
I was to anxious to get started, I should've measured the no-load amps at least.
It had 13.5turns of what looks like 30awg, I need to measure it.
On hand I have a large roll of 24awg, some really good 24awg from the motor shop and some odd "23.5"awg wire.
I first thought of 2 strands of the "23.5" with 6turns but I couldn't pull it off.
I could get 6turns of the "bad" 24awg.
Running MotoCalc suggests that even with 5turns, with 2 strands of 24, It's only going to have 1500kv.
So now I'm think 3turns with 3 strands of the 24 ought to get me close to 2800kv.
Is this logical, or at least semi-logical, reasoning?
Ideas and opinions on winds would be helpful too.
03-21-2009, 09:10 AM
1200 rpm and .83 v out.
Thats more than 1200kv (divide the rpm by the volts - not multiply)
13.5 turns - how does one get a half turn? Its actually 14 turns
To get 2800 rpm from this motor, just use about one third of the original turns. Try 5 turns as suggested
Remember that this motor is a DLRK wind (one can tell from the number of magnets and stator knobs)
Take your time winding it if this is your first time. It gets confusing with a DLRK as the coils are wound in alternate directions. Also did you check whether it was wound delta or wye.
You should use a prop not much larger than 6 inch at these sorts of RPM and when you test it use a wattmeter. The specification for the motor rates it at 14.5 amps.
Use the thickest wire that you can fit in there but don't get too worried about it. there is not a lot of difference in resistance for the few turns you want to use.
Also read some of the motor winding threads. If you wind neater and pack the wires in (it takes practice) you will get in plenty of turns.
03-21-2009, 02:10 PM
1200 rpm and .83 v out.
Thats more than 1200kv (divide the rpm by the volts - not multiply).uh...
DOH! I botched that on two different calculators even though I knew it, and even then missed the mistake DOH!x2
It's not my first time but I'm still pretty new to winding.
When the turn starts one way and switches to the other tooth is kinda a half.
Termination is Delta.
If it's wound Wye, for better ESC sensing(?), then the turns would be 3(?).
03-21-2009, 03:00 PM
DLRK winding manual:
03-21-2009, 03:04 PM
Thanks I have one of those too to wind. The 7t of 22 is looking good for that one.
03-21-2009, 11:05 PM
Finished winding with 5turns (2strands) of 24awg.
It was harder than my others, it came out ugly, but it has no shorts(!).
It came out to .53vAC so approx 2200KV.
So I'm thinking of 4turns (3strands) of the "23.5"g.
03-30-2009, 12:11 AM
Got it finished a little while ago. No chance on me fitting it to a plane now.
It was too windy to fly all day so I wound the motor instead of finishing it's test bed.
Four turns, two strands, of 24BWG.
All three legs measured .44vAC. 1200/.44=2724kv
No load current with a automotive scope inline measured 3.89amps.
I only have an odd assorment of props onhand and most of those were drilled to fit larger collets.
I tested with a APC 6x4e.
Thrust measured 28ounces, with a SuperSimple ESC.
Reversing the numbers works out to approx 20k rpm and 75mph pitch speed.
This ought to turn a 6x5.5 APCe pretty good.
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