Author Topic: a little gem  (Read 21710 times)

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Offline bcalmed

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Re: a little gem
« Reply #30 on: January 23, 2012, 03:03:25 pm »
Hi Mike,

Well, you've got me into this too, now.

I'm just a newbie - I've fooled around with an ECM and PVC blades on a too-short tower for a couple years.

Just got a Sanyo P6  -  2000 RPM, 2KW, 200V, 14.6A ($100 on fleabay).

Spun it with a drill and I get ~14Voc from (any) two of the large pins through a bridge @ 375 RPM - 1.8A into a 12.3V FLA at that same speed.

I get about 60Voc @ 1550 RPM and the voltage curve seems linear.

Questions:

375 seems pretty fast for cutin - do I need gearing?

If not, what size/type blades would you recommend?

What happens to the voltage/current when all three phases are being used (no 3 phase bridge yet)?

Thanks for any and all answers and suggestions.

-Rick

Offline 97fishmt

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Re: a little gem
« Reply #31 on: January 23, 2012, 07:51:49 pm »
Cool Rick, you're on your way to having a real nice wind turbine!

Get another bridge rectifier or two and then measure your volts.

It will be fine, no gearing, the rotor is your gathering device so,
a nice set of blades is going to make it work.  Skimp on the blades
and it wont work. 

I run a 6' prop  on those most of the time.  It depends on your
wind.  You could get away with an 8'er.  It's all about getting
into good clean wind.

Have fun building,  It will pay off. ;)

Mike

Offline klsmurf

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Re: a little gem
« Reply #32 on: January 23, 2012, 08:46:19 pm »
Hi Mike

I too, am servo-curious. I've recently scored one that works by the numbers, but has cogging issues.
Have any that you've tried, had this?

The motor is a 6 pole 240V 29.5A     I get cut in at 275rpm @13.6V which looks good to me, but I'm a noob. I'm just afraid it will take a gale to get a set of blades to turn.

Thanks for any input.      Kevin
"A man's got to know his limitations" ---- Harry Callahan

Offline 97fishmt

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Re: a little gem
« Reply #33 on: January 23, 2012, 11:17:49 pm »
Well Kevin,

That is a little high for 12 volt charging.   It doesn't mean you can't try.

I never have tried a 6 pole motor.  I know the older motors can have
a slight cog or gear feel to them when spun. 

I have a pile of brushed motors that are super generators when they
finally get up and spinning.

I'm building an engine driven generator from one I don't think has a
low enough rpm for a turbine.

A fast 8'er could do it for you.  Big wires to the battery and maybe.
Give it a try.

Offline klsmurf

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Re: a little gem
« Reply #34 on: January 24, 2012, 07:27:59 am »
Thanks for your reply Mike. I really appreciate the post you and Adam (Birdhouse) have made regarding the use of servo motors.
I believe I've read most all you've posted here and elsewhere. Keep it up!

I knew the motor was marginal to begin with, but you gotta start learning somewhere. Besides, for me the fun is tinkering!

Kevin
"A man's got to know his limitations" ---- Harry Callahan

Offline 97fishmt

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Re: a little gem
« Reply #35 on: January 25, 2012, 05:34:14 pm »
I got some of those raptor blades from eBay to see how they will work
on some of these smaller motors.

 They look real good and have a nice hub.

 I'm not sure about how many blades will work best but, it would
be nice to find a nice combination to work for some who don't want to
carve blades out of wood.

Testing, testing and more testing.


Mike

Offline bvan1941

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Re: a little gem
« Reply #36 on: January 27, 2012, 03:17:15 pm »
97fishmt,
Have been studying different Servo specs and found some interesting differences in trying to figure out projected V/RPM ratios.
Servo specs stated example:      400V, 5.4 amps, 1.3KW, 1500rpms

If you take the stated volts (400v) divide that into the (1500)rpms =3.7 rpm s / Volt. Which would give a 15V cut-in =56RPM'S

Now, if you take the stated amp(5.4A) and divide the given power (1.3kw) by the stated amps,= 240Volts = 6.2 RPM/V
15v cut-in would give 94 RPMS.

The cut-in for both figures are quite good for both but, give a pretty good expectation of results. Was wondering if your calculations and experience are are similar?

My point is using simple formulas and taking stated specs for the Servos,  there is some differences----- If I'm not making any mistakes in working the formula P= Volts (X) Amps as a way checking / estimating projected output.
Bill


Offline 97fishmt

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Re: a little gem
« Reply #37 on: January 28, 2012, 03:46:55 pm »
The numbers on the name plate of a motor are not all the numbers to look at.

If you can find a manufactures data sheet on the motor your looking at,
it will help you figure out how it will work as an alternator.

Here is one with lots of data.
Happy reading.  :)

Offline bvan1941

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Re: a little gem
« Reply #38 on: January 28, 2012, 04:29:04 pm »
97fishmt,
Thanks for the reference, I've saved it to evaluate potential servos. I'll look for more on Mfrs. I intend to buy.
I'm getting anxious to receive my parts ordered.
I wanted to order the Powermax low wind 8' blades but, they're out of order. Had to order the 9' model for now. Intentions are to use them on the larger Servo I'm hoping to purchase soon. Any thoughts on using these ?
It has been fun working out potential outputs from units listed online.
thanks ,
Bill

Offline 97fishmt

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Re: a little gem
« Reply #39 on: January 28, 2012, 04:42:02 pm »
I have the 8'er.   I got the hub modified with a taper lock hub welded on but haven't balanced
the blades yet.

I run a 6'er on a 200 volt 1500 rpm and get 30 amps out of it sometimes.
The blades are a little noisier than carved blades but they are cheap and
they work nicely and should last a long time.

I just got the hub modified for a 13'er and can't wait to get it into action.

Here is the Baldor spec sheet.

Mike

Offline bvan1941

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Re: a little gem
« Reply #40 on: January 28, 2012, 05:02:59 pm »
97fishmt,
Thanks for those references and personal experiences with blades. It's a good feel for me at this stage.
How is that "big motor" project coming along?
Bill

Offline 97fishmt

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Re: a little gem
« Reply #41 on: January 28, 2012, 05:17:50 pm »
I'm always playing around at home here in Seattle with wind generator parts and blades,
fooling around with motors and welding up mounts and hubs.

My wind site is at my cabin.  I have 3' of snow there now so it might be tough to get the
big blades up there.  I'm sure I will try but right now it's by snowmobile.  I don't mind walking
in.  It depends on work and when I can get away.  Soon I hope.  The blades sure look nice.
I just finished the hub.  Now I need to mount and balance the blades. 

I have been running a 10' prop on that big motor and have been getting 80 amps @30 volts,
so it is working pretty good.  It sure is fun to make your own power and use it to build more
power producing devices. :)
Take care
Mike

Offline bvan1941

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Re: a little gem
« Reply #42 on: January 30, 2012, 05:13:09 pm »
To all servo users,
I've purchased a Fanuc Servo(red cap)  # 10F TYPE AO6B-0351-B731 pulse coder.

Currently have removed the coder from the backside, trying to release /remove the brake assembly. Have found an aluminum  "press fit" round plate blocking further disassembly. It looks like the case might have to be split via (4) recessed Allen- head screws,  located on the shaft side of the motor.

Question: Are these "Allen screws" metric sizes? My Allen wrench 7/32" doesn't seem to fit correctly. I'm afraid of "rounding out" one or more of these in the process.

I would appreciate any assistance / advice, on the correct process for disabling  the brake.

Bill

Offline 97fishmt

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Re: a little gem
« Reply #43 on: February 09, 2012, 08:11:24 pm »
How about some pictures?

 :)

Offline bvan1941

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Re: a little gem
« Reply #44 on: February 09, 2012, 08:57:41 pm »
Mike,
I'm going to try taking some pix's and see if I can post what I've done. This will be all new to me, posting Pix's. It's a good thing Adam posted a pix of his "brake project," I know it really helped me!
Maybe that will help some new members of the "servo community" that's growing here!
LOL !
Bill