Advice on dish wobble in wind

[thecaretaker]

Put up my new Fracarro Penta dish last week. Yesterday however, I noticed the feed arm wobbling violently in the strong breeze. I would describe the wind as brisk, not a gale.

I double checked the bolts holding the arm were tight, but when I got up to the dish, noticed it was actually being caused by a tiny amount of play in the motor leg. The instructions that come with the motor show how to tighten any free play, but the free play is so small, I can't seem to tighten it up anymore. What seems to be half a millimetre play on the leg, shows as 1-2 inches of movement on the lnb.

The movement doesn't seem to affect the signal and I can carry on watching channels fine.

Is this amount of movement normal for a 85cm dish?

I'm just wondering what will happen when I do get a gale. Will it be able to withstand such violent movement? Will it damage the motor?

I've not noticed this before on smaller 40-60cm dishes. I'd appreciate your experiences on this problem.

 

[acezon]

Have you tried this method??

http://www.satellites.co.uk/satelli...280-backlash-adjustment-moteck-sg-2100-a.html

 

[satelliteman]

Although from what you describe the backlash being 0.5mm, this sounds ok.

 

[thecaretaker]

These are the intructions I had for my motor. I assume it does the same thing. (below)

Looking at the motor end, I can't really see any movement at all it is so small. But by the time this is exagerated down the arm, it looks very noticable at the lnb.

If there was too much movement, wouldn't I have problems getting the motor to stop at the correct positions for the different satellites?

I was hoping I'd get posts like "Yes, don't worry. Mine wobbles all over the place and it has been OK for years". I guess I'll have to wait for the first gale/storm and I'll see if I get any damage.

 

[satelliteman]

Don't worry mine wobbles all over the place and it has been OK for years

 

[compufunk]

Same here, we'll for months

We've had a few storms since I installed and it was fine, apart from the whole kit moving a few degrees around the mounting pole on one occasion.

 

[fantom007gr]

the best thing to do is that :
take down the dish again
take the drill and start make holes to the dish with the drill.
imagine how can you make it look like a mesh dish
take care where to make the holes so you wont damage the structure.
then the air can pass from the holes and it will be more stady.
what do you think my friend?

 

[satelliteman]

Destroy a perfectly good Penta 85cm I'd say, lol

 

[wod]

make some metal support arms for the lnb arm and fix to bottom of the dish to stop it moving about in windy weather

i don't have this problem with using a channel master dish

 

[fantom007gr]

i see lack of fantazy

 

[fantom007gr]

most of the times you have to destroy in order to create

 

[Topper]

Destroy a perfectly good Penta 85cm I'd say, lol

I agree SM, if the holes are over a certain size the signal will no longer bounce off the dish to the lnb but will pass through it. Have a close look at your microwave door if you want to get an idea of the max diameter of the drill holes you would need. I suspect even if you could physically manage to do the drilling without breaking the bit you soon run out of patience before you had got halfway across

 

[Channel Hopper]

I double checked the bolts holding the arm were tight, but when I got up to the dish, noticed it was actually being caused by a tiny amount of play in the motor leg. The instructions that come with the motor show how to tighten any free play, but the free play is so small, I can't seem to tighten it up anymore. What seems to be half a millimetre play on the leg, shows as 1-2 inches of movement on the lnb.

The movement doesn't seem to affect the signal and I can carry on watching channels fine.

Is this amount of movement normal for a 85cm dish?

The answer is no, but the motors that are currently on sale for around 40 - 50 pounds will often be assembled by monkeys.

Unless you can reduce the backlash you will never find that weak signal you bought a decent 85cm dish for, and there are plenty of others you might never realise are there.
Don't forget the play is probably in all directions, meaning your true arc is most likely out as well, and low elevation satellites are just impossible to catch.

Buy a decent motor if you can, only another 20 quid or so.

 

[thecaretaker]

Well, I've been at the top of the ladder all day. I managed about 6000 holes but I've gone through 28 drill bits so far and I'm on my 3rd Black and Decker. The neighbours called the Police as they got fed up with the ruddy noise of the drill. Unfortunately, I've got a cold and when I sneezed the darn dish was so weak from all the holes, it broke in half at around 4pm hehehehehehehe

Do you really take me for a numpty?

I think the last suggestion is probably the best option and your siggy says it all Channel Hopper. There is a very fine line between "hobby" and "mental illness

I'll keep an eye on it for a while. If it gets worse, I'll look into getting something better.

At least you made me laugh fantom007gr, something I haven't done all day! Thank you for that anyway.

 

[Navalcarnero]

which are the best makes of diseqc motors? I was thinkign of getting one to go on a 1.2 m channel master

 

[Robbo]

I don't think that you will find any of the Diseqc motors are really 'man' enough to go on the CM 1.2m, although the Super Dark motor is reported to be suitable for up to 40kg and 1.4m, but never tried it on that sized dish. A Jaeger 1224 36V would do it easily for sure though.

 

[Topper]

Do you really take me for a numpty?

I think the last suggestion is probably the best option and your siggy says it all Channel Hopper. There is a very fine line between "hobby" and "mental illness

Even if you give everyone plenty of slack on the rope at least will hang himself ;)

 

[wod]

which are the best makes of diseqc motors? I was thinking of getting one to go on a 1.2m channel master

can only use a jaeger 1224 motor, which i use on mine, or the polar mount if you can find one

they are too heavy and would wear out a diseqc motor quite quick

also if you did try to use one on the dish you would need to make a mount as they aren't standard pole mount dishes

 

[thecaretaker]

Well, after 3 days of playing, I've finally sorted the problem (sort of). I first followed the instructions to tighten a loose tube by turning the side screw. Only to find it slowed the motor up considerably, so I loosened it back again.

I checked the bolt on the tube which was tight.

Later on during high winds I noticed the actual inner works was moving around inside the casing. I could see the allen key holes (x4) all moving inside the case holes. So I tightened them further. It improved it a bit, so I really gave them some welly and it solved the problem.

However, the dish being alloy does have a high degree of flexibility itself. It is no-longer moving the tube, but does move from the screws that hold the dish to the frame. I checked they were tight (which they were).

I can live with that as the dish is obviously designed to flex a little. It was a combination of both the loose tube and the flex in the dish that made it look so drastic.

I did take some time to see what alternative motors are available. The most expensive seem to be STAB motors (almost £100 each) but they don't appear to have any method to adjust a loose tube and reports on forums made me wonder if they are as good as some at half the price.

Still, mine is working OK now and I will monitor it to see how it goes. It is a super dark motor and people keep referring to it and recommending it on forums. I will have to replace it one day and really don't know what make is best. Lets hope that is a long way off. I've got some serious enjoyment to get out of my new Fracarro yet

 

[satelliteman]

I always use the steel version, anyhow, well done