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Old Sep 13, 2004, 06:31 AM
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Small LRK outrunner

Quote:
Originally Posted by mcross
Gordon
I had to machine all the parts except the stator stack. I have one of those mini lathes from Harbor Freight. The original motor had windings on the stator and rotor so I could only use the rotor. It weights 3.9 grams.
Mike
Wow mike,

Could you post some pictures and instructions as to how you did it? I have 2 Unimat 3 lathes set up for milling and lathework but I don't know where to begin to start adapting these CD-Rom motors. Any help would be appreciated.

Thanks.

Gary
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Old Sep 13, 2004, 07:02 AM
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Quote:
Brian,
I've only tried it wired star
aah ha ... and how have you wired your star connections (I can sense Ron smiling when he reads this)

Brian
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Old Sep 13, 2004, 07:34 AM
homo ludens modellisticus
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No, just banging my head against the wall
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Old Sep 13, 2004, 08:15 AM
It's a spiderweb of knit lines
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Gary
I don't have pictures. You need to start with some practice parts that are simple and work your way up to more complex stuff. In other words get on that lathe and practice.

Brian and Ron,
I have tried every different way to connect it in star. On an inrunner this control chip requires that phase 2 start and finish be switched, I've tried that too. My control chip requires a common connection (the center of the star), but I can fake it out with electronics. I'll try that tonight.
Thanks,
Mike
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Old Sep 13, 2004, 08:57 AM
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Mike ..
I see you are playing with something else other than a commercial controller. Canít help you too much there at present, but have you tested the motor with a normal controller to see that it works properly?

PS: What are you using to drive your motor. What chip?
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Old Sep 13, 2004, 08:59 AM
pem
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HI Mike

great work ! possibly you could measure some rpm and amp figures with prop - even if thrust has to wait a little bit.

I never ran into such a small multipole stator. Did you make a note on the motor model and any specs ? Did you really save half of the stator ? - can we trade ?
Possibly a minidisc 6-pole stator for exchange ? (more winding space ...)

Peter Maul
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Old Sep 13, 2004, 09:24 AM
It's a spiderweb of knit lines
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Chip is a Philips TDA5144, I do have a Pheonix 10 and will try that tonight.

Mike
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Old Sep 13, 2004, 09:35 AM
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Mike ..

When you report back, take note of how you wire up your star please.
PS: It should be every second wire around the stator being connected for the common star point.

Good luck
Brian
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Old Sep 13, 2004, 06:56 PM
It's a spiderweb of knit lines
Souderton Pa. USA
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It works! I have to flip the prop to start it, but it does run. It is wired as Brian says in the above post (same as the inrunners I make). My problem is mainly with my controller chip, I need to adjust the start cap. My power supply was also going into current limit. And at over 3 volts it exceeds the speed the chip is capable of. I still have a lot to do on it, but at least I know it works. Here are some numbers; GWS 0320 prop, 3 volts, .954 Amps @ 6420 RPM.
Thanks Brian.
And Ron, I hope you didn't hurt yourself!
Mike
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Old Sep 14, 2004, 12:41 AM
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Glad to hear the good news Mike. Well done.

PS: To start the motor, you do need a fair amount of current. It might be that your PSU cannot supply the required amps. Have you tried using a battery pack of any sort to confirm this?

Brian
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Old Sep 14, 2004, 05:35 AM
It's a spiderweb of knit lines
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Brian,
I'll check it with a battery but it seems to be doing what the chip's data sheet says when the start cap is the wrong value (oscillating). The start cap is also dependant on the inertia of the rotor, outrunners have a lot more inertia than inrunners.
Now I need to get some kind of thrust rig so I can do some winding development. Then I need to make a filter so the chip will be throttlable from my RFFS.
Thanks
Mike
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Old Sep 14, 2004, 05:46 AM
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Quote:
I'll check it with a battery but it seems to be doing what the chip's data sheet says when the start cap is the wrong value
Oh ..ok .. was thinking you had trouble starting with Phoenix 10. Did motor start Ok with phoenix controller?
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Old Sep 14, 2004, 06:20 AM
pem
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Hi Mike

during the tests with my 3 Gramm Outrunner the problem of extremely high inertial Amps also occured. I only could avoid that with WEAKER magnets.

Peter Maul
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Old Sep 14, 2004, 06:21 AM
It's a spiderweb of knit lines
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Brian,
I haven't tried the Pheonix 10 yet, it needs more volts than I want to use this motor with. My aim is to have a 1 li-poly cell setup to use with my RFFS.
But I'll give it a try tonight.
Mike
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Old Sep 14, 2004, 06:24 AM
homo ludens modellisticus
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Peter/Pem, what do you mean 'inertial Amps' ?

Met vriendelijke groet Ron van Sommeren
diy brushless outrunner discussion group
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