Prodelin 1.2 offset on polar mount

[phlatwound]

I picked up a Prodelin offset a while back:

http://www.satelliteguys.us/free-air-fta-discussion/168344-prodelin-1-2-lnbf-suitability.html )

and was wondering about the setup angles required to get it tracking the arc?

I did some study on turbosat's Primestar on a polar mount setup, and it gave me some ideas, but still have some questions.

I have it narrowed down to 2 possiblilities:

1.) Set the mount elevation and declination same as prime focus dish, and then create an adapter that will face the dish down an amount of degrees that equals the offset angle. (I think this is it).

or...

2.) Set the mount elevation to the proper figure, but have ZERO declination in the mount (mounting ring parallel to elevation bar), and then create an adapter that will face the dish down an amount of degrees that equals the offset angle.

Or, possibly the most like scenario.....

3.) Phlat aint got a clue, but would really like to hear the correct way to do it!



I was hoping to come up with an AJAK H-H (or similar) for this project but I don't see it happening, I do have a stack of polar mounts and actuators looking for a nice dish to carry though.

My thought is for this dish to be Ku-only at first (possible min-BUD later), linear actuator, driven by a G-box.

Thoughts, ideas, rants and ramblings are all welcome, thanks.

 

[Anole]

Well, I think the down-tilt of the declination and the down tilt required to get the dish to aim properly, are pretty much cut from the same cloth.

BTW, your #2 proposition should have read: "...and then create an adapter that will face the dish down an amount of degrees that equals the offset angle plus the declination", I think.

Didn't Turbo start out with a standard mount, then make an adapter to down-tilt his dish the same as its offset?
That seems the most straightforward, so long as you have proper travel in all your moving piecces or adapters.
And if I remember, that was what held him up at the beginning: no way to down-tilt the dish enough.
But he solved that with pieces from a DirecTV or DishNetwork mount.
By adding both together, he finally had enough adjustment range.

Also, isn't that pretty much what 1captain did when he adapted a small H-H mount for a similar dish?

Shame you didn't just continue the thread this started in.
That's one pretty dish, and the LNB comments are relative.

 

[phlatwound]

Thanks Anole, well that explains what I was confused about, that is, is the declination angle amount even required (now I know it is), and if so, does it matter if some of that angle is picked up in the mount and some in the adapter....or can it all be factored into the adapter?

Yes, that is what turbo did, very cool project, here it is if anyone hasn't seen it, check it out.

http://www.satelliteguys.us/free-air-fta-discussion/100414-new-project-primestar-polar-mount.html

Ah yes, I need to look at what 1captain did, I forgot about that one! That was a beauty if I remember correctly.

I guess I should have continued the other thread, maybe Mr. Iceberg will merge them sometime when he's making the rounds.

 

[phlatwound]

Here's the link to 1captain's 1.2-to HH mount thread....some really nice work there also, can't believe I forgot about that one.

http://www.satelliteguys.us/free-air-fta-discussion/160314-captain-s-1-2m-h-2-h-mount.html

 

[turbosat]

Phlat>you're on the right track. You set the polar mount up for proper elevation and declination for your site, for prime focus dish. Just like you had a 10' dish on it. But you have to get the extra 22degrees or so difference in the offset, as in-between a prime focus and an offset-dish. Once you have that built-in, it will work. I'm still using mine , but less often since I got that DG380 installed yesterday.
Now, an offset ku dish on a polar mount WITH AN HH MOUNT, that would be something!
Not until I got my DG380, had I ever owned any kind of HH mount. They rule.

edit; Oh and thanks for bringing up my project thread on the polar mount. With my engineering talent, I'm still amazed that I was able
to make that work. (even with all the help I had here!! LOL)

 

[Anole]

Yea, if I had a 6' Prodelin, and a spare AJAK H-H (even one of the smaller two), I'd mate them with an offset adapter.

Below are some pictures from Europe, similar to what TurboSat made up.
There, they have regular kits to do the job - it's not so uncommon.

 

[1captain]

Plat what help me out here was to read at the Prodelin web site about their polar mount, after spending 2 days to get it to track from Telstar-12 to Gal-18, help a lot.

now you're declination angle is added to you're offset angle of the dish that you are working with. now in you're case dealing with a know dish offset angle an you're declination of you're area you should be able to set all with a angle finder an then be able to track fine. but in my case did not the dishes off set angle so it took some time to get it right.

going to bring that post back once I get the home painted an set a pole for the 1.2 meter to be at it final resting place, already got it wired, but other things first.

good luck Plat, an you will enjoy have a good gain ku dish on a motor, they smoke for signal, just wish I could fine a 1.8 meter then will change it out.

 

[phlatwound]

I'll check out the Prodelin site for their polar mount info, thanks Captain.

I don't know the specs on my dish but can the offset angle be determined by putting a straightedge vertically against the face of the dish, and then measuring the angle between it and the LNB support arm?

As soon as I get some poles planted this project will be slotted in right after one of my Birdviews goes up, can't wait.

Maybe I can even come up with an H-H mount for it by that time, if not I need to start studying what kind of pulse counts come out of a linear actuator, and how a G-Box handles those.

Thanks to all for the pics and comment, keep them coming, heading out for a weekend of girls basketball near the City of Wind, soon.

 

[1captain]

Plat when you're at their web site look for the tech info on the model of dish you have they will have it in their spec sheet. believe me this make things easy, on getting the tracking set up.

now as far as getting more counts out of a actuator, I am working on a 20 magnet wheel right now for a von weise V-76, got all the magnet sitting in the freezer to be pressed in when I get the time, an that is for a Channel Master H to H mount that I fabed a V-76 motor on it, works lot beter than the channel master motor, the CM motor always seem to be under rated running that dish.

 

[phlatwound]

Well I've taken the disc off of the Prodelin frame, and am trying to figure out how to mount the frame/LNBF support onto the polar mount.

My thought now is to weld a piece of 1/4" flat stock, +/- 4" wide, horizontally to the face of the dish ring, then weld a couple of ears perpendicular to that plate material.

These ears would be spaced the width of the dish mount/LNBF support arm, would have holes for the pivot bolt to go through, and would be tall (long) enough to allow the dish to pivot down at least far enough to equal the offset angle.

If all that will work I will probably put an elevation adjuster (allthread, to adjust, set and hold the offset angle allowance) from the tab that is already on the top of the Prodelin mount, to a tab I'll weld on the polar mount ring.

I'm basically just trying to reuse all the existing Prodelin holes, pivot point and mounting tabs on this polar mount.

Crazy???? You tell me.

Any thoughts and suggestions are most welcomed, thanks!

 

[gremlin411]

Phlatwound.
I do not know if you have looked at the Prodelin site yet are not but the offset for your 1.2 meter is 22.6.

 

[1captain]

Phlat after looking at pictures of what you have, I would not use that ring, will me moving the dish out far an put a strain on the offset weight. an the polar mount from prodelin is only about & $250.oo an a lot less work.

what I would do would remove ring, from polar mount, use the angle that is on its lower pivot point (declination adjustment now) an weld 2 flat stock on the sides of the angle to be you're lower pivot point, (looks like a 5/8" bolt in prodlelin mount). then get a about 2 1/2 angle an drill a hole in for the top pivot point in you're polar mount (now I would leave this a little long for now will use it for the actuator to push an pull). on the top H of the prodelin mout will need to weld 2-taps so you can bolt a treaded rod to (for declination an dish off set), also should leave long till get all figured out. then drill 2 hole in angle iron (top pivot point equal to the same spacing coming off the taps you welded on prodelin mount) now this will give you a swing dish execpt for the actuator, just need to get the right angle to put a tap on the top pivot oint to weld to the 2 1/2" angle for the actuator, an still use the back mount where the actuator mounted before.


this may help you, 1 picture lower pivot point, 2nd top pivot point, note the sloted holes that the 5/8" stainless rods bolt too, this was need to get the nuts to seat flat on the bar that locks them down, an 3rd picture side view of my mount.

 

[phlatwound]

Thanks for that info Gremlin, there is a lot of info on their site, good stuff.

Thanks for the thoughts and pics, Captain.

I see what you mean about gettting that much weight extended that far out from the pivot point, might be too much. Never even thought about removing the ring but I understand that it is just there to interface with a round dish, and I could use anything that will pivot on the mount, as long as I can set the elevation - (declination + offset) angles with it.

Still looking at a possible AJAK H-H for this project but don't think it's going to happen so looking at going polar....back to the drawing board.

 

[Anole]

wants AJAK ?

Well, if it's a small AJAK you want, put the word out.
NObody can read your mind.
I thought you had this mount idea pretty well under control.
But, if an AJAK would suit you better, let people know.

Someone might have an unused or spare, and make you a deal.
Couple of years ago, I asked. Nobody answered.
I never thought I'd see one in person, then somebody offered me mine at lunch.

To swing a 4' dish, I will guess that the smallest Patriot model might work (?)
Here are some pictures posted by Glater of that small unit.

 

[gremlin411]

Phlatwound you are welcome.
Prodelin quoted me 240.00 for a polar mount for my 1.8 meter I have not got it yet LOL.....
I just noticed the Ajak mount looks like the HH180 that Sadoun sales. I think it would be great for a 4' dish and they had it on sale a while back for under 100.00.

 

[phlatwound]

Thanks for pointing me to the pics, Anole, those are nice. I have been pursuing an AJAK locally (the only one I have ever seen around here), and haven't gotten much of a response, but haven't given up.

I'm almost to the point of actually offering some MONEY for it!!!!!

 

[phlatwound]

Phlatwound you are welcome.
Prodelin quoted me 240.00 for a polar mount for my 1.8 meter I have not got it yet LOL.....
I just noticed the Ajak mount looks like the HH180 that Sadoun sales. I think it would be great for a 4' dish and they had it on sale a while back for under 100.00.

Does Sadoun still carry the HH180? I wasn't able to find it on the website but seem to remember them blowing them out for $49 or $59 a few months ago. I heard they had some problems the gears being torn up by wind on a 6' dish, maybe?

 

[gremlin411]

phlatwound I could not find them either I think they are not selling them anymore. And you are right they had problems on 6' dishes with wind load breaking the housing. I think it was 60 plus mph.

 

[Anole]

... I have been pursuing an AJAK locally ..., and haven't gotten much of a response, but haven't given up.

I'm almost to the point of actually offering some MONEY for it!!!!!

OMG, you ARE getting serious! - -
I'm sure it's in the threads I linked, but I believe the little Patriot weighs around 30 pounds.
I have the large model, which I believe is called the 180. It weights in about 63 lbs.
Linuxman has posted some pix of the intermediate model recently.
I think it has two sets of chains, internally. No clue on weight.
Either the small or medium should sling a 4' dish.
If you found the big heavy model 180, it'd be a waste to use it for such a little job.

Check also in our Manuals & Documents Department for further guidance.

edit:
Say, as long as you are considering the expenditure of money... both for a motor and a Gbox 3000 to run it...
Have you given thought to the big H-H motor Sadoun sells, the 380?
I'd seriously evaluate that alternative. No Gbox required, so quicker 'n cheaper in the long run.

 

[phlatwound]

.....Say, as long as you are considering the expenditure of money... both for a motor and a Gbox 3000 to run it...
Have you given thought to the big H-H motor Sadoun sells, the 380?
I'd seriously evaluate that alternative. No Gbox required, so quicker 'n cheaper in the long run.

The DG380 would definitely be my first choice (couldn't be happier with the one I have been using for a year) but I believe there is just too much weight there for it to handle.

The bare reflector is right at 30 pounds, then if you add for any sort of mount, LNBF and LNBF support it's going to exceed the 31 pound limit by a ways.

If I use the factory frame/LNBF support like I am planning on, the weight is close to 50 pounds, with reflector.