linear actuator not moving

[ringram]

I just finally got my new (old) 10' bud connected last night. I was able to move the dish east and west. I locked onto a satellite, and then tried moving to another. The dish wouldn't move.

The receiver shows that the dish is moving (the dish location changes). I go to the dish, and I can hear the motor turn, but the arm does not move in or out. This was moving earlier in the evening.

It is currently in the middle of the travel. The name on the side of the actuator is "Von Weiss". Is it possible something came undone or loose inside? Or, is it more likely that the gears are shot. I'm hoping it's simple. It was too dark last night to start taking it apart. I'll find out tonight.

I was hoping somebody might be able to share some of their perspective on this.

thanks.

Roger

 

[linuxman]

Is it possible something came undone or loose inside? Or, is it more likely that the gears are shot.

It is possible that something came loose in the gear box.

These actuator have a long rotating threaded bar that a short threaded fiber ring rides on. If you didn't take it apart and grease it before you started, it might have had rust on the long threaded bar which may have already eaten the fiber ring's threads down to nothing.

I had that happen on one of mine.

 

[ringram]

That doesn't sound good. I picked this whole unit up this summer. I don't think the guy greased it in a couple of years. But, the system was working at his place. I had it working, and was panning the satellites a couple of times before it stopped. It didn't stop while moving. But, just wouldn't move when I wanted it to. (if that makes sense).

I'll find out tonight. I hope for an easy (quick/cheap) solution.

 

[Davage]

I have re-built my parents Von Weiss arm about 3 times. That Fiber ring does get shredded pretty easy if there is rust on that threaded rod. I replaced the original fiber ring with another fiber ring that I bought from the satellite dealer, but it only lasted about a month and it was shredded too because of the rust. I took a wire wheel to the threaded rod to clean it up, greased it up, and luckily an uncle of mine is a machinist and he made a new brass ring to put into it's place. That brass ring has been working for about 10 years now. I've had to open up the arm, clean up the threaded rod, and grease it again just this year, but it has done very well. I don't know why they'd build the arm with a fiber ring in the arm instead of a good brass (or other metal) ring...

 

[ringram]

That sounds like to most likely cause of my problem. I just wish I would have opened it up a cleaned/greased it before I did anything. Hopefully, I can repair it.

 

[linuxman]

luckily an uncle of mine is a machinist and he made a new brass ring to put into it's place.

That's what I need to do with this one of mine. It works fine in every other way. Maybe I can get my machinist buddy to make me one out of brass.

If it works, I'll have them all re-fitted.

 

[gabshere]

there is a place online that listed these but man it would take me a while to find it and i think it was about 25$ but i will find it later and post a link , i actually thought it was a nylon / rubber bushing but i didn't check it close. The brass ring bushing might be the more feesable and cheaper option.

 

[SatPhreak]

I had an acuator that did the same thing about 9 years ago and it was the fiber ring. As everyone says, clean off the rust and grease the shaft / ring.

Or, if money is not a problem then you could upgade your acuator for one that has recipricating balls instead of the fiber ring.

 

[ringram]

Got it apart tonight, and yup, it's that nylon bushing. It's about 2 inches long. It's really just a nylon nut that goes up/down the threaded shaft as it turns. The rust and dried up grease is what wore it out.

I wish I knew about this before I hooked things up!

Now, did somebody say they found a link that has a replacement part?

The shaft is 5/8". I tried to spin a 5/8 nut onto it, but it's a different thread pitch. Maybe it's more of a pip thread. It would be nice if I could just replace that shaft with a section of 1/2 or 5/8 threaded rod and put a nut in place of that nylon bushing...

 

[ringram]

OK, that nylon bushing is called an "ACME NUT".

My actuator is a Von Weise V76-8. According to some info I found, it is an 18", 48 pulse count.

I can get replacement reed switches, but I can't find a link for the acme nut, yet.

 

[ringram]

Found this link. I can order the nuts in plastic or bronze.
Lead Screw Nuts - Acme Bronze & Plastic Sleeve Nuts - Part Numbers & Dimensions - Roton Products

 

[gabshere]

here's one for the von weise


Von Weise nylon acme nut for 24” actuator jack

plus i'm still looking
the site you listed those parts arent cheap either

more
acme nut

 

[linuxman]

Try fasco.com and get the phone number and give them a call.

Von Weise used to be Fasco Gear and Motors. They are very helpful, and will sell you the part you need. They are in St. Clair MO.

Fred

 

[linuxman]

Roton Products is in Kirkwood MO.

I am within 20 minutes of there at least once a week. I could retrofit all my actuators with their parts. They even have the worm gears. They may be a reseller for Von Weise.

 

[ringram]

The plastic ones are about $21, and the bronze about $23. Not bad. The link on the site you listed is $25. At this point, I'm tempted to purchase a bronze acme nut and fit it into my unit. I just need to figure out if it's 8 tpi or 10.

 

[ringram]

You can also get a flange nut or hex nut cheaper than just a plain acme nut.

Roton Products, Inc. Quality Lead Screws and Nuts for Power Transmission

 

[ringram]

This site shows the nut and rod a little bit better.
ACME screws and ACME nuts

Here's another supplier if you just want a simple steel hex nut.
Enco - Guaranteed Lowest Prices on Machinery, Measuring Tools, Cutting Tools and Shop Supplies

I called up a local supplier, and they have them in stock. I'm going to put a steel hex nut in then end of the pipe. As long as there is enough grease and good maintenance, I should have no worries.

 

[ringram]

I bought the nut, a 5/8, 8 tpi. I got home and tried it. And, of course, the rod is 5/8, 10 tpi. I was so close. Looks like I'll have to find another supplier. Hopefully locally.

 

[markinredding]

Attaching the new nut

I have two of the actuators and the nuts are fine, it's the nylon clip that secures the extension tube to the nut. Both have broken, disintegrated actually. Replacing the clip would be quick but in my case I am using it for a solar array. The wind loading is obviously to high. I was considering machining a much wider, maybe 1' wide, bushing and boring holes for metal pins that would connect the extension tube to the nut.
If I were to get a metal nut, are you guys drilling receiving holes into the metal nuts and using pins or the original nylon clip to attach the extension tube?
I will fix the two actuators I have for smaller arrays but due to the high cost of the panels, 4k, I am looking at the 24" heavy duty drive to this array. In fact after this last storm, we had 80 mph winds, I'm making solid struts for winter time.

Thanks

 

[Anole]

I don't know why they'd build the arm with a fiber ring in the arm instead of a good brass (or other metal) ring...

I had a discussion with a buddy today. He's a manufacturing guy, and machinist .
His answer was that you don't want to damage the expensive screw.
So, I guess the wear is taken by the cheaper nut.

That would certainly be a problem if you used a steel nut.
And if my ears didn't deceive me, that's all the local industrial hardware store had: steel.
I had high hopes to find your part for $3 ... $5, and ship everybody two.

I'm not a mechanical guy, but if I'm not mistaken it's Delrin you would want in the nut, not nylon or fiber.
I'll talk to some materials experts and get a better idea.
Teflon would be nice, but might be too soft, and most likely way too expensive.

As a last resort, I wonder about custom-making some of the replacement nuts?
My machinist seemed pretty interested, if he could use a fairly soft material.

So, if anyone has a worn-out motor they'd like to contribute to the cause, I'd be happy to pay shipping.