Removing brakes from Servos

[bvan1941]

Bill,
You have it exactly correct, I used the original hub on the treadmill motor and used flat bar steel about halfway out and then bolted the pvc blades to the flatbar on the "inside" part of the blades. They are very quiet and at speed, one has to "listen" to distinguish  between wind noise and turbine sounds. Yes I'll try taking a picture of my first W/T still running. Looks crude but used what I had at the time to test out what I wanted to do.
Bill

[bvan1941]

Bill, borrowed my wifes Ipad, ran out in rain and snapped a couple of pixs to give you some idea of what our discussion is about. Not the best pixs during this rain, hope you can see OK, if not I'll take some better one when rain stops.
My tower is only 31' at the hub.
Bill

[tomw]

Bill;

Are there guys anchored in the water? How does that work?

Tom

[wilfor03]

Bill,
You have it exactly correct, I used the original hub on the treadmill motor and used flat bar steel about halfway out and then bolted the pvc blades to the flatbar on the "inside" part of the blades. They are very quiet and at speed, one has to "listen" to distinguish  between wind noise and turbine sounds. Yes I'll try taking a picture of my first W/T still running. Looks crude but used what I had at the time to test out what I wanted to do.
Bill

Boy, you're quick, Bill

I blew up the first photo enough so I could see what's up. Gotcha now, understand what you're saying. Might give that a try on the smaller servo soon.

What a nice "back yard" you have and I noticed you didn't waste any room for your tower mount, either....Way cool, Bill. I like the way you have your tower mounted.

Do you get any shaking down at the bottom of the mount? I'm shooting a picture of the tower I made. I really love it......takes about 2 minutes to lower it all by myself,

just using a 1200 lb boat winch, and no guy wires (yet). Seems extremely stable without them, still. Even in the super heavy winds the other day. 

Thanks for the info and pictures and hollar if I can help ya with anything, okay?

Bill

 

[bvan1941]

Tom and Bill,

Tomw--The guy wire placements are temporary and not anchored in water but to the posts (front two away from camera). Second two, one tied off to right hand post of the platform holding woodpile. The close left side is tied off to a telephone pole on the corner of the cabin (just out of picture to the left).
Right after the project went up, I contracted Cancer and am just getting back on my feet. I will redistribute the guy wires more equal in geometry and use turnbuckles for adjustment. This will serve as a"test" tower. Winds are predominately from NNW (5-10 degrees to left looking at WT).

Bill---After 2 years  I've noticed some minor shaking at some low wind speeds. Must be some rotor inbalance, maybe from pvc blades not tracking exactly?  Believe the sun has worked it's magic on the unprotected pvc. It's why I applauded you painting your blades. I was going to use your tilt upstyle system, but the leverage potential wasn't working for me.
The tower made from scrap and welded by me, is heavy walled pipe and has been very stable.

Thanks for the good words and look forward to your next project, I've enjoyed your present creation very much.
Bill

[bvan1941]

Tried to post my project of "removing brakes" on a YASKAWA Servo, with pictures---- They went to the "ERROR BIN"- I guess!
I'll try again.
Bought a Yaskawa servo with brake and tachometer attached. After taking off the rear Tach housing, then the tach, I Tried 2.5 days more, trying to use the "noodle," to split the brake and stator cases, to no avail!
I could scarcely get a 1/64th of an inch separation of the cases. Unlike the Fanuc process, It felt like I was missing a bolt or bolts holding the cases together.

Then, my bride came in, heard my woes and said these words of wisdom "Why don't you call the people you bought it from, either they know how or will know who to have you talk to."  SOOO I DID! In (5) Min's. I had the "secret"  I'll share with you!

Yaskawa applies COMMERCIAL GRADE LOCKTITE all around the outside of the bearing and in the race on the housing !!

The answer to removal is, use a heat gun to heat the bearing shaft area and the aluminum housing for 5-8 Min's. until it's almost too hot to touch!
This softens the Locktite and the housing pops off the bearing (with some words and work) which STAYS attached to the armature!!

Hint: use two people! One to keep heat on while the other splits the case apart. ( this stuff is really, really tough to work with, if not continuously heated)  Be fairly easy on the aluminum housings! One has to use thin blades at first to gain some small case separation, then some judicious use of BIG SCREWDRIVERS  and some wooden blocks to widen the case separation. Unlike the Fanuc there are few stators coils or wires to be aware of and are visible as you gain progress. I will try poisting some more pictures now, hope it works this time! I have more pixs-- If there's more questions or interest.
Bill

[97fishmt]

You don't always have to buy one with a brake.

Maybe try to make one with a brake work.  The brakes
only take a couple watts.  You never know you might
be disabling one and then want to put it back on.

I have a very large motor that I haven't gotten around to
that I actually plan to use the brake on it. 

Keep us posted Bill.  It's great to see new stuff going on.

Mike

[bvan1941]

Mike,
Good to see your back on again. Yes, I can buy them without brakes and I did give some thought to utilizing the internal brakes for "parking" should it be necessary. If you do incorporate the internal brakes, Let us all know how it works for you.
I am working on finding some strong tower pipe to put on the first direct drive project (with Fanuc Servo).

I know some people don't know what the inside of a Servo looks like, so I am trying to contribute some firsthand knowledge and experience by documenting with pictures like you and Adam have done in the past. I was surprised to find the magnets on this Yaskawa have rounded stator cores. Believe this is meant to minimize cogging.

By the way that brake assy in the Yaskawa weighs about 10-12 lbs. nearly fell on my foot when it popped off the bearing!!

I'll try to keep posting progress on my projects as I go along.
Bill

[bvan1941]

Gents,
Don't want to "hog" this section but I wanted to say in my discussion with the Servo service Tech, I asked him if I pulled out the armature would I destroy anything including the magnetization. He said absolutely not, he takes them out everyday and they don't lose any power or loss of manetization in the process!
This question was for my benefit but, I know the question was being discussed on this Forum and others. Thought It would be another contribution from a Service Technician that repairs Servos for a living.
Bill

[97fishmt]

Do you mean arched magnets?

They are actually skewed to eliminate cogging.

Go ahead and pull the armature out and take a look at it.

It wont demagnetize,  I can't believe that myth still
floats around.

I took a motor apart today also just to shed some weight.
Just the encoder,  but yes it does add up.

The motor I was referring to is a large brushed motor.
So I wouldn't be able to stop it by shorting the wires
together.  I've had it for around 15 years and it just
sits in the basement.  100 volts @ 1000 rpm and 180 amps
It was before I caught on to ac servo motors.

Mike

[bvan1941]

Mike,
No the magnets are rounded to fit the arc of the rotor. I was talking about the stator cores (like the modified stator cores  that use the F&P motors). I'll see if I have a close up of this motor showing the magnets and stator cores. Try and see if this pix shows enough detail to illustrate what I'm trying to say.
Bill

[bvan1941]

Mike , my mistake your right !!!
Bill

[97fishmt]

ahh...  you had me thinking and trying to make something out of your photo.
I know there are many overlapping coils that make up the three phase winding,
I thought that's what you were getting at.

Keep up the good work Bill,
I love it!

[ghurd]

"he takes them out everyday and they don't lose any power or loss of manetization"

Wondering if it has to do with the age of the motor?
New motors with neo would not lose power.
Maybe the old motors have far inferiour magnet material?

I do not know how old the ones I took appart were (other than 'very old'), but the magnets in them were lame at best.
G-

[bvan1941]

ghurd,
I can't contribute any observation other than what I've documented here.  I trust what the service technician said and Mike's 20 yr. experience with servos. Is there a chance you had come across a servo that had been abused in some way, thereby giving the impression of loss of power as a result of being taken apart ? Have you made any W/T's built with a servo?

I'm gaining enthusiasm for these units and the power they can potentially provide. They certainly are ruggedly constructed!
 You always provide good advice and patience. Glad to see your part of this Forum!
Bill