servo motor testing

[97fishmt]

I tried to get some numbers for you folks on that servo motor I took apart.

Here's the name plate:

Here's the open voltage with a dewalt 6.7a 1200rpm 3/8 drill motor.

Then I hooked it up to a pretty flat 12v battery.  It measured 12.01 before I hooked it up to the rectifier. Here is the voltage all out on the drill.

And the amps.

O.K. so, I'm wishing for a new meter for my birthday but we'll see.  I was able to paint a red spot on the shaft and count the number of times it went by in 10 seconds. Not scientific I know but, thats what I got for now. I counted 30 spots in 10 seconds wile charging at 13.00 volts. The battery was a little flat but, no noticeable drag. Between 12.5 and 13.0 still 30 counts. So, 180 rpm for cut in.  I don't know max output and at what rpm because thats all the drill would do. It has to really grunt to push it like this. I'm sure it's not even going 1/2 the rating on the drill motor (600). This also was just a cordless drill motor battery, if I had one here with more capacity I'm sure it would hold the volts and rpm down more.

Any how, it gives me an idea of what size blades to put on it and get it up to the cabin. I'll let you know how she does.

[gizmo]

I pulled the servo motors out of the robot last night. I've got one rated at 90 watts, two at 130 watts, two at 1100 watts and one at 2200 watts. These things are awesome. I did find mine had magnet brakes in them, being a robot you want it to lock solid when the power is switched off, so each servo has a magnetic break that needs power to release. I dont think this would be any good to regulate the windmill or stop it completely, so I've romoved the brakes. I fired up the little 90 watt on the electric drill  and got 2 amps shorted, about 30 volts open circuit at about 500 rpm. The 1100 watt motors gave the same voltage but got over 20 amps ( the limit of my multimeter ) when shorted. I have to agree, these things would make fantastic wind generators. All you would need is a 3 phase rectifier. And like you said there is virtually no cogging at all, so they will start up in the lightest of winds.

Glenn

[97fishmt]

gizmo, you made my day! I'm feel if I passed something off to just one person, then I've done what I set out to do on this board. These motors are $$ new but, like in your case, you were just going to sh*t can that machine.  Thats all I'm trying to say with my posts is, they are out there  just waiting to be found. Just read Hugh's workshop book, he states they can be found. Well now you know and maybe a few more but, lets just try to collect up these motors quietly for our wind projects and not drive up the prices. cheers!!

[zap]

97fishmt I figured I'd post the original post of you taking that motor apart.  http://www.fieldlines.com/story/2005/4/8/0544/27885

Plus... don't make that good ol' Fluke jealous!  Unless of course your new one will be another Fluke!  I'd love to know how many 77's they've made, I've looked around online but never found anything.  My trusty 77's been going strong for years after quite a bit of abuse although I must admit my $20 cen-tech from Harbor Freight is pretty impressive for the price.

[97fishmt]

cool (I spelled that wrong in my last post), I need to measure frequency to be able to determine rpm, I know the fluke makes an 87 or 88 or maybe even something newer these days. That 77 was one of the best $25 I ever spent.