Strong winds strip actuator

[armadillo_115]

Per the title: Strong winds last night/today stripped the actuator on 'my' bud. (Wife's seems ok)
I noticed the dish was all the way over on the eastern side. I manually raised the dish back and it stopped right on 116w, but does NOT lock in. It will freely extend to the east. Something broken inside. I temporarily tied it in place.

It was getting too dark to see well, but I don't believe there was any damage to the dish or mount. Dish is receiving ok on 116w, which is the western sat of main interest for the wife.

Will have to take stock of my old spare actuators tomorrow. Best I recall, the only complete actuator remaining uses an optical sensor and will need to be converted to reed switch. Sure wish I had done that before when it was not needed at the time. :rolleyes: * There is also a working pots type actuator and controller that could be used as a last resort. *

Sounds like fun? lol

[el bandido]

Take it apart and see what happened if you have the time. My guess is the screw broke.

A few years ago, actuators were fairly cheap if you bought the junk ones from China. I had a few "new" ones that never seemed to last much more than a year. But they were cheap to replace. So no big deal really. And of course the positioner errors these cheap actuators produced were provided at no extra charge.

Today, a decent 36 inch ball screw actuator will cost around $500.00 new. A decent 24 inch ball screw will be about 100 dollars less. The cheap actuators if you can find them are usually over a hundred dollars or maybe around $200.00 for a cheap 36 inch satellite actuator. IMO, the good high priced actuators are the ones to have because they do not give any problems if properly installed.

Re-using old actuators is a thing I also tried with mixed results. But usually positioner errors followed any used actuator I put together or refurbished, regardless of what I did to it. Yes. They could be made to work and move again...Kinda....Sorta.

An old actuator with decent tube and screw can be made into a manual dish mover if you get a little creative. Tack weld a turning device of your choice on the motor end, allowing you to turn the actuator by hand is an economical and usually a long lasting fix for a c band dish mover. Then again, maybe not such a good idea if you live in a cold climate and decide the dish needs turned at 11PM.

Shown below are a couple of pictures of actuators that I use. These are Venture actuators and they are noisy. But they get the job done, and they don't throw positioner errors or lose counts. These actuators are a blessing to have after years of doing it the hard way. Problem is they cost money. I think the cost of actuators has almost doubled in the last 5 years.

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[armadillo_115]

Any idea where I might order a reed switch (preferably with bracket} for this Uniden UST-705? The magnets sit approx 1/2 inch above the metal plate. I'm guessing this magnet wheel was optional or a conversion.... since I have an identical Uniden UST-705, that is optical.

I would order TWO reed switches while I'm at it. Try to make a magnet wheel and convert the optical Uniden UST-705 as well. But that would be a longer process. Need to get the one running asap.
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Dug around in the spares all afternoon. I have a decent spare shaft and 2 or 3 motors with reed switches ... but none mate up. Just my luck!

[el bandido]

What about fixing the one that broke --or is that even an option?

[Only registered and activated users can see links]

[armadillo_115]

I doubt the old shaft is worth fixing. I tried taking one of SuperJack HL's apart before and had no luck getting it back together again.

I'll google around and see if I can figure what specs I need for the reed switch. I believe there is 5 volts on the sensor wires, but not sure.

[el bandido]

A few years ago, this would not be a big deal. The Uniden UST-705 served many satellite dishes well, but today, it is just hard to find parts for anything like that. And finding a New replacement that does not break the bank is almost impossible. The only thing I see reasonable today is an 18 inch actuator.

[armadillo_115]

I found an old post on SatGuys where Magic Static told how to do the mod on a similar actuator. (The Uniden was supposedly a re-badged Von Weise) And luckily there is a link to order the reed switch that he used! I'm going to order a couple and go from there. It may be tricky making two new magnetic wheels with the tools I have on hand.

I still need to determine if the magnet strength matters. More googling to come. Thanks for the help so far. :bigthumbup:

[Terryl]

Now, once you get it all fixed and back together, there is one way to keep this from happening again, (info to others that also have a BUD) what I do to mine is to anchor it in place when I get a storm warning, I first swing it due East or West to the hard stops,(depending on the direction of the incoming storm) I then turn off the Vbox or receiver (to keep the dish from being moved when anchored) and using some anchor points I put in the ground I install two guy lines to the side of the dish.

The guy lines are interchangeable, they can be switched around depending on the East/West hard stops I used, simple eyelets installed on the rim of the dish, and in the anchor points located in the ground at equal spacing's from the dish work wonders.

Note: if your anchor points are located in the lawn, be sure to install them low enough to keep from hitting them with a lawn mower.

[el bandido]

Anchoring the dish for a storm can be a good thing. Similar to tying down an airplane. But it is a fact that we are running out of actuators to use as replacements when something breaks. I had several spare actuators at one time that had been collected from one place or another. And not too long ago, cheap actuators for satellite dishes were available at several places. But not today.

At some point a new actuator will have to be purchased or an old actuator will have to be converted to manual operation of some type. Do you need a reed switch or any switch at all? How about moving the actuator by just connecting power to it and bypass the switches? This is something to think about and switch-free system is probably "doable" in some form. But what are you gonna do when the motor quits and there are no replacements?

IMO, a good quality actuator is a great investment for more than one reason. The problem with a new actuator is they can cost some money. A cheap 24 inch actuator at WalMart for a satellite dish is advertised at less than $200.00. But how long will it last? An expensive actuator may not last long either, but generally well made products last a while unless abused.

Shown below is the cheapest new 24 inch actuator that I could find.

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[armadillo_115]

Now, once you get it all fixed and back together, there is one way to keep this from happening again, (info to others that also have a BUD) what I do to mine is to anchor it in place when I get a storm warning, I first swing it due East or West to the hard stops,(depending on the direction of the incoming storm) I then turn off the Vbox or receiver (to keep the dish from being moved when anchored) and using some anchor points I put in the ground I install two guy lines to the side of the dish.


The guy lines are interchangeable, they can be switched around depending on the East/West hard stops I used, simple eyelets installed on the rim of the dish, and in the anchor points located in the ground at equal spacing's from the dish work wonders.

Note: if your anchor points are located in the lawn, be sure to install them low enough to keep from hitting them with a lawn mower.

Terryl, I agree with the above. But this actuator was old and half wore out when I mounted it. It was well due to strip out. The winds we had were not near as high as we often get. I SHOULD have turned it a bit more directly into the NW winds though! At best, I may have nursed it along a couple more months. Live and learn I guess.

[ArloG]

If it matters. Using a super-crap 36" actuator here.
It's gone through several stages of encoder mods. I finally got it working very accurately with 20 pulses/revolution of the actuator shaft.
First stage was using an old vcr gear with 12 indexes around the perimeter to glue magnets to.
It worked but was kind of flaky. The Amazon neodymium 4mm round magnets were too strong. They need to be sharpied on one side to keep track of the N-S poles.
I found out that some of the magnets had different strengths. So I had to redo the disc. Strength matched with a needle and thread on the bench with the magnet ref. distance.
Sorted a bunch that had the same strength.
That worked better. Had to make a small mod of the reed switch mountand testing to make sure it triggered ok when a magnet passed it.

Next I did a hall switch conversion. I didn't get what kind of control you're using but I have a ASC-1.
With 3 wires out to the actuator (including the shield). All that was needed was 5 vdc to the hall. A ground, or common. And trigger, or sense, wire.
Magic Static used a reed switch interface at the ASC-1 to simulate the reed switch normally used in actuators that work with it.
I use a SSR. Because I have a box of them. Easy to make and no switch bounce.
The hall sensor is one of the Amazon 6 for 1 packages used with Arduino projects.
It is a true switch with a Schmitt trigger output. Current sink (open collector). And the SSR is Schmitt output also.

Again. Another small bracket and positioning the sensor for solid triggering worked pretty good. But the neodymiums are strong and the magnetic flux is freakin' big.
I tried a few different incantations of magnets. As small as 2mm, tiny bar magnets. A 20ppr magnet disc didn't pan out well because the magnetic flux from the smallest magnets on a wheel that would just fit inside weren't spaced enough to eliminate completely flux overlap. And the same issue caused a long "dwell" when the hall turned on and then back off.
I needed snap action.
The Amazon halls are cool in that they have an led to tell you when they are switched on. But I could never position them to give a nice square wave pulse stream using my 'scope at the dish.
Wash!

Went to an optical thru-beam sensor. Cut a piece of old black plastic "mystery enclosure" from the box-o-junk into a disc. Again. Just big enough to fit in the motor case.
Got another 6-for Amazon package of thru beam optical sensors with Schmitt trigger outputs. With leds to tell you when the beam was blocked.
The disc has 20 slots cut around the perimeter. A little crafty printed paper index wheel fitted around my drill press quill drive pulley with a pointer.
A Dremel in the press vice. With the thinnest cutoff wheel they make.
Fit the disc in the chuck with a long machine screw and nut. Index the quill wheel and lower the wheel. Slice a slot.
Move to the next index. Do it again. And made a slotted trigger wheel.
Same deal as with the hall conversion. A little adjustable bracket. Optical gives excellent "snap" action. And 'scope waveform is almost a perfect square wave with nice +/- transitions.

ASC-1. 127W to 40.5W. Something like 4200 pulses on the counter. And repeatable.
I got chewed a while ago about motor drift. Yes. You do see motor coast when the actuator shuts off. And more noticeable using a high res. encoder.
Solution? A crafty little relay inside of the motor housing that acts as a dynamic brake with a .22 ohm emitter resistor as the braking resistor.
Man. When that actuator hits dead nuts on the center of a sat. That armature....Stops! Super repeatable positioning. Even after "bumping" the E-W control when searching and peaking sat signals.
So. There you have it.

My next actuator will definitely be a Von Weiss. Perhaps a Venture. This super-crap has lived a cat worth of lives. You gotta' take 'em apart and grease them. Or run 'em until they puke.
But honestly my 12' solid 'glass dish has never creeped during a heavy storm.

[el bandido]

Hopefully my days of working on and modding actuators for satellite dishes are gone. I installed the 36 inch Venture shown in post# 2 on my Prodelin c band dish in the early part of 2019. Above 61 west, you can start-stop-call a satellite-stop calling a satellite-manually bump the dish east./west, or do pretty much anything else that has to do with moving and not lose your sync. I had some positioner errors in 2019 due to water, but don't recall having any since. So far, I guess you could say I paid a hundred dollars per year Not to have dish moving problems.. The only thing I dislike is it is noisy.

The 10 foot mesh started having dish moving problems in 2021-2022 with errors and over-shooting or under shooting a satellite. No real explanation for the errors as they would just happen randomly, without a clear reason. Finally the actuator quit and it was replaced with an old spare. It wasn't long though and dish moving problems started again. The 10 footer got a 24 inch Venture ball screw in early 2023 and have had no dish moving problems since. Dish actuators wear out and need replacing at times. It is that simple. A properly running actuator does not coast.


We should take things apart such as actuators and fix them. But we can only do so much. It gets hard to fix something when replacement parts are not available. Sometimes modifications work very well. Sometimes they don't. One reason why satellite tv is a hobby!

[ArloG]

It would probably be a good statement that of all of the components of your sat. system. The actuator is probably going to be the one thing that gets replaced and hits the bin.
In my case my bin has a pile of 24" tubes and motors. Saginaw gear. Probably a few Venture rebadged ones. A few no-namers with a Houston Tracker hall sensor.
And. I rebuilt the polar mount pivots and used pillow block bearings. Plus modded the actuator mount geometry to be able to use a 36" actuator. Solved the dish flop syndrome.
At the time I ran across a brand new super-crap 36" actuator. A big mistake but at 60 bucks. Why not?

Having popped a few of the old tubes open. Acme screw versus ball screw units. Spend the bucks guys and get a ball screw.
Two schools of thought. Run 'er 'till she pukes. Or take a little time and service it. All of the acme tubes had the factory charge of grease clumped up like a ball of clumped-up wax inside. Grease was grease no more.
And the same with ball screw ones. But the balls still were working and everything looked great inside. The bronze bearing units had a lot of slop. Ball construction were still tight.
Water intrusion made the guts inside nasty.
So. Knowing that I drilled a shallow hole in the super-c*** tube down by the motor end and screwed in a Zerk just deep enough to not interfere with the inner tube.
Every year it gets a few shots of Lucas low temp. grease. An entire extend/retract cycle. And a few more squirts. Grease will ooze out of the accordion and motor end. And any gook gets flushed out.
At -20 here. Although very slow. I get no motor errors. Something a gaw-ja person would never realize. Dad had wrapped the tubes with heat tape and a sleeve of pipe insulation.
The motor is not so bad to pull apart and oil, grease. And check the brushes. Super jacks, Venture. All of them will need brushes. And the bronze bearings fed a few drops of earl.

Or. Toss it in the bin every few years. And accept that your tube will cost you 25 -50 cents a day to own.

Now.I can buy the fact that a 4 or 6 magnet encoder will exhibit less positional errors over time. And that a new, tight motor and gear train and tube bearings will provide enough friction to keep armature coast to a minimum. But I'm pretty darned sure that over a period of dish movements and sat. searching, "bumping" E-W to peak signal and storing the position. Errors will occur. That slight motor armature coast when the relays open will add up.
At least the ASC-1 has a fix built in. I use 127W for my 0 reference. Things get off. I spin it down to 127 and peak the signal and do a resync. And all is good.
But. With my hair-brained 20 ppr encoder. Slight coasting adds up fast.

It would have been nice if the ASC-1 had its counter at least active a second or 2 after the relays opened. Or better if it kept it on all of the time for the instances where wind "might" actually manage to spin the actuator a touch. But that's not the case. And the code is locked in it so a firmware mod is not possible. And it's all good!
My little dynamic brake works darned well. The motor stops almost in its tracks when the controller kills juice to it.

As mentioned. Perhaps when I do happen to get the samolians for a Von Weise or Venture tube. All of that crap will disappear too.
For now. I'll milk mine for every last inch of its life.
And hey! I managed to get past my rant of the mods made with both "cheeks" intact. That's cool!!

[lme]

I learn my lesson with the super-crap, made in china acct long time ago.
Even the original actuator (from 19Osummer !), witch came with the dish, was better then those junks... is a bit rusted at the mounting end, but it has a 2" strong tube. I keep spray it from time to time just to save it as a last resort.
bought 1st Venture ACMe. no more problems. After 8 years, last march I decided it's better to replaced it with a new one
just as a precautionary measure. Not that the 1st Venture is bad, but i noticed some play in the shaft...is still working.
Von Weise is a dream these days. You may be lucky to find an old dish with a Von Weise on it still working.

[el bandido]

Here is a link to a store that still has a few parts left:
[Only registered and activated users can see links]

Don't know if they have anything that will work or not but they also sell new actuators if needed or wanted.


I think the Accordion Boot for the actuator tube helps a bunch as far as keeping moisture and dirt out of the working parts of the actuator. It might also be a good idea to get a cover for the motor too, especially in cold climates. The site listed above also sells actuator heaters which is what I would have if I lived in Alaska or anywhere else where the temperature goes below 0 degrees. Installing boots, covers, and heaters for a cold climate should give a smooth running system.

[lme]

Well, this vendor I deal with last month, has not updated his web page in centuries !!
Before ordering, I advise to call him (Jim), to find out if listed items are still available.
I ordered online a chaparral corotor 2, and he sent me a wideband type !!!, not perfect for NA, despite the fact that in the description of this product on his web page, he stipulates that wideband is suitable for other parts of the world !!!
He returned the money, and didn't want the feedhorn back !!!
Asking him about any chaparral products, his reply was what everyone knows: Chaparral is out of business !!!
Why he is not updating his web page: he couldn't answer....
Although, the last Venture actuator came from Venture factory, so I think he does not have in stock everything is listed.
So, I think that he may not have Von Weise in stock. I hope I'm wrong.

[ArloG]

Well. A few years ago when I tried contacting Von Weise directly at the TX phone number. No joy.
After a few emails. One fine day I received a phone call from a very nice man with a Spanish accent. Von Weise moved operations to Mexico.
We had a very good conversation. At the time only 24" actuators were listed. He assured me that I could get a 36" unit tailored to my needs.
High ratio gear reduction. Hall sensor (only pots and reeds were listed). I was told that they build per order. If a company wants 10, they build 10. With very little wait time.
They are heavily into the medical supply industry for beds, treadmills and such for manufacturers.
I considered them the Cadillac of actuators.Trying to contact Venture directly got me nowhere. Maybe things have changed.
I did discuss a quantity buy and perhaps a discount thinking maybe doing a group buy thing would be cool. If I could get enough people to commit.
From memory. Mind you the '70's were good! A full mechanical drawing and parts list could be sent also.
Having the owner call directly was a very nice experience.

[el bandido]

I think VonWeise moved to Mexico for most of their current operations. Good luck on finding 2 or 3 fta folks willing to fully commit to a cash or card type transaction as a group buy. Doubt that happens with a fta group.

Thomson Saginaw I think still makes actuators for satellite dish applications, but expect to pay a bit more than Venture.

Venture Does answer their telephone and are knowledgeable about what they sell. That is why I ended yup with two of their products. |

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[armadillo_115]

I called Venture a few years back. A nice guy asked what I needed, dish size, etc. He explained about the pulse count I needed, differences between acme and ball screw, etc, etc. Probably talked 20 minutes or more with me. I remember he priced a 24 inch acme and a 24 inch ball screw but don't recall the prices at the time. As it turned out, I happened upon a decent used actuator with the 12 ft dish. (Still to be mounted :hide: ) And I never ordered a new one.

If I ever buy a new actuator I hope to go with a 36 inch. Preferably ball screw type. And Venture is probably who I will call. The attention that tech spent with me was quite impressive. :yes2:

[el bandido]

Hopefully you will fix what you have. But at least you know what to do if you can't fix it. :pray:

[Terryl]

My actuator went fubar a long time ago, and I cant find parts for it, (OEM channel master, wheel cog for the reed switch) so all I did was move it tot the satellite with the HD NASA channel on it and fixed it in place, this until I find a replacement actuator that wont cut too deep into my budget.

[armadillo_115]

First attempt at magnet wheel pic below. Magnets are pressed into tight holes in middle plexiglass sheet. Thin plexiglass sheet is glued on each side. (Magnets entrapped) It may not show well in photo, but magnets are NOT perfectly spaced apart. Drill creep thru off the alignment.

I know I could just mount it to test. BUT, the wheel needs to be glued onto an optical disk. Be a PITA to glue it on, then have to remove it. Any ideas if this will be usable as is, or should I attempt to make another wheel with better spacing to begin with?

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Any micro cracking shouldn't be an issue since three plexi sheets are glued together. (Many are heavy sanding scratches for a good bond, not cracks)

[el bandido]

What you have to me looks good. Probably cannot do much better unless you get into a place that has equipment to make this stuff. Another thing to consider is whatever you do will probably be wrong. If you don't mount it, then you should have, and if you do mount it then you should not have.

My opinion is you should mount what you have already assembled and see how it does or does not work. It might work fine like it is for what you need it to do.


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[clucas]

My first actuator had magnets that alternated polarity N then S, N then S, etc. on the wheel. The sensor screwed into a white plastic mount so that it could be adjusted in or out to miss the rotating wheel. The sensor failed and I replaced it with a reed switch in a glass tube by soldering #14 copper wire to each end. The wire was stiff enough to hold it all in place. Worked fine but my count doubled which was an added benefit for Ku. I guess back then the magnet would either pull on the internal workings of the switch then push it out assuring full motion of the switch.

[armadillo_115]

After thinking some more: I can temporarily mount this with a hot glue gun. Center only. Shouldn't be too hard to remove if necessary.

First; I'd like to rig up a AAA battery and light bulb circuit to determine the distance to mount the sensor. Visualize what is going on since I don't have high-tech test equipment. I will have to build a sensor mount from scratch. (Maybe make it adjustable) I believe these little magnets are too strong, but embedding them in the plexiglass will lessen their strength. Plus the magnets will never drop off.

I plan to bring actuator inside the house to do the testing. Weather too unreliable to do much outdoors.

[armadillo_115]

My first actuator had magnets that alternated polarity N then S, N then S, etc. on the wheel. The sensor screwed into a white plastic mount so that it could be adjusted in or out to miss the rotating wheel. The sensor failed and I replaced it with a reed switch in a glass tube by soldering #14 copper wire to each end. The wire was stiff enough to hold it all in place. Worked fine but my count doubled which was an added benefit for Ku. I guess back then the magnet would either pull on the internal workings of the switch then push it out assuring full motion of the switch.

One of these actuators had a 4 magnet wheel, but NO sensor or bracket. Not sure how the magnets were orientated since they jumped out of place when I removed it from the shaft. Magnets are large in diameter and I don't believe they would function with the double count switch I bought.

I could have tried a single count switch with this magnet wheel.... but didn't want to be limited to only a four count wheel. If my homemade wheels don't work, it may be a fallback option. (Or I could remove the large magnets and glue my small magnets in their place, and use a new double count sensor.)

Time will tell.

[ArloG]

Glad to hear a little crafty experimentation is happening. Can I help keep the head banging down a little?
From #26. And from what clucas stated. Once you understand a few thing that I found out over time, hopefully building your own encoder wheel might help you get it working faster and better.

Clucas stated that he converted from a Hall sensor to a reed switch. And his counts doubled. Understandable.
Reed switches for the most part just need a magnet close to them to open/close the "contacts".
Because his counts did double, that leads to understanding the basic hall sensor types. More on that in a minute.

Your older magnet wheel encoders most probably used ceramic magnets. My dive into making a wheel sent me to buying a stack of 4mm diameter neodymiums.
I used an old Houston Tracker hall sensor from and old (I think) Saginaw actuator and mounted it in a Superjack.
The wheel was just big enough to clear the inner workings of the original 6 pole ceramic disc magnet.
I used 20 magnets super glued evenly around the inside diameter of the disc. Used a sharpie to mark the side on them that was the same polarity. So all black sides faced up.
Here's where I lucked out. More on that soon.
All put together and the magnet wheel mounted to the actuator shaft gear shaft in place of the original magnet. Time to position it.
I wired everything on my bench. Gave the Hall sensor 5 VDC. Powered the actuator with my 12 VDC Harley battery.

Hooked my oscilloscope to the Hall sensor output lead an ground. Powered the actuator. Quickly found out that the Hall sensor was an 'open collector' output.
So put 5 VDC in series with the output terminal and ground lead of the sensor. If you have an actuator controller with reed switch sensor inputs, you should be able to measure DC voltage at those pins. Oscilloscopes aren't good at all measuring switch closures/resistance. They are voltage/time.

Alrightey. Next I positioned the hall sensor module close to the magnet wheel until I got a nice square wave. A bit....not perfect....some pulses were wider than others. "Design error" in spacing the magnets equally? Yeah that's the ticket. Somewhat. Once satisfied with the positioning of the sensor. I marked and drilled slotted holes (for wiggle room) in the gear cover plate and and mounted the sensor. More on that too.....

Let's call this part one.

Hall sensors come in several types. Some detect magnetic strength. Imagine being able to turn radio volume up by putting a magnet closer to the volume control. Or turning it down by pulling it away. Proximity. Not what we want. We need snap action like a toggle switch.
Some turn on and off when a magnet is brought close. No matter if the N or S pole is used. They get a magnetic field strong enough, they turn on. Pull it away, they turn off. We can use those types.
Some turn on when the N pole is brought close to them and turn off when the S pole is close. Meaning you could turn one on and take the magnet away....Hall would still stay on as long as it had power on the voltage supply. When you brought the S pole close, it turns off and stays that way. Most probable the type that was originally in clucas' unit.

So. If we want to build a Hall sensor encoder. A unipolar (magnet close, no matter which pole, turns on. Pull away, turns off) or a bipolar (turns on when one pole is brought close, and is forced off when the opposite pole is present). Those are the types needed.
Most all modern Hall switches have a Schmitt trigger output. Also very important. Gives a fast and positive action. Think of a snap action Lutron wall switch that clicks versus a Decora that "kind of" does.

Coffee, chores, more on this.

[armadillo_115]

Any ideas how to set the Limits on this Uniden actuator? (Von Weise) I'm not familiar with this type. I see where it can be set... but that looks to me like it will only work for one direction. Or am I missing something? If only one limit... I will set it for maximum safe extension. *Picture taken before reed switch conversion

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Actuator has been briefly tested OFF the dish. Counts are flying in both directions, so it should give many counts between Sats. How accurate/precise it will be remains to be seen. Hope to install it tomorrow if everything goes as planned.

Thanks for all assistance!

[ArloG]

Pretty easy. The stacked microswitches and cams control the limits. From the factory the lower limit is usually already set. That's the lower cam. It's non-adjustable (unless you loosen the geartrain cover plate to disengage the gear that drives the cam). So from the factory the actuator tube is retracted all the way in (shortest) and then turned out several turns. I choose 6 full turns when setting mine up.
The upper cam is for the extended limit. Loosening the top 2 screws and lifting the cam and turning it to adjust the upper limit. Then engaging the stepped cam coupling to the lower cam and tightening the screws. You adjust it so that the upper microswitch 'just' clicks.
Of course you need to be aware of which way the cam turns when it extends/retracts.

There are cases like when you remove the gear drive from the tube that the lower limit cam will get off kilter.
Just unbolt the motor from the tube. Drive the motor to it's lower electrical limit until it shuts off. Retract the tube with a pair of Vice Grips. Spin it out, oh let's say 6 turns. And reinstall the motor.
Then you will want to verify that the upper limit is still set right.

There will be some times that the limit cams "jump right past" the microswitch and the motor keeps running. Like if a switch gets dirty or is failing, the plunger is worn.
You could get fooled and flustered because what seems to be is totally "off". Because the cam needs to rotate to the opposite side of the switch plunger. That's where loosening the gearcase cover and turning the cam gear would be needed.

[armadillo_115]

Thanks Arlo!
After looking at it better with my glasses on today I 'discovered' that lower limit. :rolleyes: And yes, it was preset for the retraction. I adjusted the upper limit with plenty of margin for error. Will determine exactly where it needs to be later.

Actuator is mounted!
On the west side and pushing up as previous one. (This dish only needs to cover the western arc) Sats are programmed in from 135w to 116w so far. Done messing with it today. Mama wants her PanAmericana NOW!. lol

135w to 116w = 19 degrees.
135w to 116w = 291 counts
15.3 counts per degree Which is higher count # than I ever had before.

I will need to slide the actuator down at the clamp 2 or 3 inches to maximize the throw. Ran out of daylight today. Finished wiring the motor wires using the cellphone light.

Whether the count positions remain accurate over time remains to be seen.

:churn::yes1::agree::talk015:

[el bandido]

I get about 446 counts from 135w to 117w. It helps to have a few more counts to align the dish better. I think a bigger dish will have more counts than a smaller dish if everything else is equal except for dish size. My experience with old actuators is they have inconsistent counts at least part of the time. Positioner setup has been modified some in TNAP images to make it more useful for dish alignment and calibrating c band actuators.

Regardless of what the counts are, you got the dish moving again without spending hundreds of dollars. I call that a Success any day of the week. Congratulations!

[ArloG]

Awesome!
I have my 'cheat sheet' in a ring binder. Across the arc you find that sections of it need more or less pulses to travel so many degrees.
So even though I have some 40 sats located and stored already. I know that for...lets say 0 is my starting point for 127W. For easy resynching of the ASC-1 when things get out of whack.
From 127-125 I get 125 encoder pulses. Or right at 62-63 pulses/degree (don't know how to do the little degree character).
As I extend the actuator from 113 to 111. I get 142 pulses. Or 71/degree. Then 101-99.2 turns out to be 129 pulses. Or around 65/degree.

I have a 36" tube. It lets me cover 131W (damned trees) out to 40.5. Everything from zenith. Or let's say around 81W out to Britain. Counts get a bit freaky due to the actuator to dish mounting geometry.
So 58-55 turns out to be 66 pulses. 22 pulses per degree.
All of those stats are logged in my book-o-notes.
Since I scanned in all C band sats first and my ku lnbf is offset by 6 degrees from dish center. And my channel list is divided by C band first and then ku band. To keep the dish from swinging all over the place when peeking around. Interpolating where a sat 'should be' is a lot easier.

I have as many sats scanned and stored as I was able to. Even if they don't have viewable channels. Because sometimes they do have wild feeds. And transponders are added and deleted on a whim.
I just don't know how those dudes actully do discover wild feeds. If they sit there scanning the arc and scanning every single satellite looking for periodic channels, a newscaster picking his nose in dead air. I don't know.

[armadillo_115]

Slid the actuator UP about 1.5 inches today. (Believe I mistyped that it needed to slide DOWN in previous post) From 135w to 87w = 787 counts. Averaging 16.3 counts per degree. Counts increasing as it gets closer to zenith.

I may build an 8 magnet wheel for the other Uniden actuator instead of a 6. Not sure how that will work with magnets spaced closer together. No rush to get this other one done since it will be a spare.

Taking these actuator arms apart were MUCH easier than the SuperJacks! Remove the 3 screws connecting the arm to the motor, then the acme screw just screws all the way out.

The acme screw and arm had some dry rust and old grease powder. I wire brushed the acme screw pretty well and applied some rust remover. Greased it all up with some gear oil and a small dab of bearing grease. (All I had handy) Seems to ruin nice and smooth now. I need to add a grease fitting to the arm later. An accordion boot would be good as well.

Time to watch tv! :talk015:

[ArloG]

I didn't get to add to my previous encoder rant. But briefly. You have to beware of neodymium magnets and spacing them closer to try and get a higher resolution.
The magnets are so strong and if you don't allow adequate spacing between them, the flux will overlap and the sensor will see it as one continuous field.
The idea is to get as much spacing as you can. If you have the room inside the motor to build a bigger wheel, you should.
And I mentioned I had started out with a certain size of magnet. I ended up getting the smallest ones. I think 2mm. You need that tight rise and fall of magnetic field.
Not so bad at slow speeds. Like when I bench tested mine with a 'scope. But once it was up to full speed on ASC-1 voltage. I started getting errors that didn't show at the slower speed.
And I used a hall sensor at first. A reed switch on high resolution was a no-go. The hall was very high speed with Schmitt trigger.
But still.....

Next. You really should check each and every magnet you use for equal strength. That was one of my issues. It took a bit to figure out.
Even with a precision divided encoder wheel. I was getting long and short pulses. It kind of flustered me.
I took the wheel out of the motor and benched it. Put it on a piece of wood with a hole drilled for a machine screw for a pivot.
"Borrowed" a sewing needle and thread. Taped the thread to the board at a distance where one of the magnets passing it would attract it.
Sure enough. Some magnets would lift the needle and attract it pretty good. Others didn't so much.
So. Hand select them for equal strength. And mark one side with a sharpie so you know what pole is what.

I have 3 incantations of magnet wheels. I'll dig those up and put up a few pics.
Two use 2mm disc magnets and one uses bar magnets.
Hall sensors have a window defined on them. That's in the data sheet for them. The 2 wheels using disc magnets should have been built with the discs around the perimeter of the wheel.
If you search for the key words 'neodyumium disc magnet flux characteristics' or something like that. You will see why.
Placement of the sensor. Whether hall or reed switch is a bit critical. Too high of a resolution on a small wheel with closely spaced magnets, for me, was just very inconsistent.
And. With closely spaced magnets. And many of them on a small wheel.
Actuator controls like the ASC-1 stop counting as soon as the relays in them deactivate. If you spun just the encoder wheel, the ASC-1 wouldn't care
Just a small motor coast will add up in errors. My 'scope has a pulse counter function. Compared to the ASC-1 and it hooked up at the sensor port. In a very short while with the actuator inside on my bench.
"Bumping" it like you would when peaking signals before saving the position. Added up 1, 2, 4 count discrepancies in a very short while.
The 'scope was always spot on. Because it has to be.
A dynamic brake consisting of that 24 VDC mini PCB mount relay with the center (relay armature) contacts out to the limit switch/motor. And the NC contacts having a .22 ohm resistor soldered to them.
With the ASC-1 motor wires connected to the NO contacts. All fitted inside the motor housing cover. Count errors reduced drastically. Not 100% when bumping the actuator E-W, W-E. But very very much better when just sending out a go-to from the receiver.

Enough. Merry Christmas!!
But. I'm going to turn you on to an optical encoder. Almost as easy as making a magnet wheel. Not one bit of tweaking for the sweet spot like for your reed/hall switch.
Just make sure the wheel slots are as accurate as you can make them. Assure that the thru beam is positioned so it either passes light or is blocked by the wheel slots.
And hope a spider doesn't decide to set up home on it. It's THAT good!

[armadillo_115]

Well it may not be pretty...

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Multiple layers of plexiglass stacked to mount the reed sensor. Reed sensor was crazy glued on lightly and tested. After it seemed to function ok, I epoxied the heck out of the whole sensor mount platform.

New magnet wheel epoxied to (trimmed down) optical wheel. Magnet wheel was a press fit, but I epoxied the center to the shaft for good measure.

I opted for strength over 'pretty' when it came to the epoxy job. I'll need to do fancier work if I open up a magnet wheel replacement factory. lol

[el bandido]

IMO, that magnet wheel should be left alone providing you have enough counts to accurately adjust the dish.

Coasting or improper counts are common actuator problems. A given actuator can only produce a certain amount of counts until you start having problems in other areas. Industrial actuators may have internal mechanical brakes which would provide a higher degree of accuracy. I think any actuator builder would tell you that actuators will have a certain amount of coast in them. If the counts get added into the coast, then there will be alignment problems. So if the dish is align-able with a decent degree of accuracy, then leave everything alone and enjoy it!

[armadillo_115]

IMO, that magnet wheel should be left alone providing you have enough counts to accurately adjust the dish.

Coasting or improper counts are common actuator problems. A given actuator can only produce a certain amount of counts until you start having problems in other areas. Industrial actuators may have internal mechanical brakes which would provide a higher degree of accuracy. I think any actuator builder would tell you that actuators will have a certain amount of coast in them. If the counts get added into the coast, then there will be alignment problems. So if the dish is align-able with a decent degree of accuracy, then leave everything alone and enjoy it!

I don't plan to 'fix it' as long as it works. Besides, we need this up and running... not on the repair bench.

I may experiment with an 8 count magnet wheel on the other actuator though. I'd also like to be able to adjust the sensor height and the in/out direction.

[Fearless]

My conversion from optical to an eight magnet wheel and double counting glass reed switch.

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