Channel Master/Laminas 1.8m project

Did you see which sections were moving ?

(I won't ask your pole girth)
 
It's tiny contributions from all over the place. Bracketry in general seems to be the weak spot, so I need to think about what I can do there. The first step is to cut off a bit of bracketry to the dish as in the last photo of post #572. But since the whole dish wobbles a little, I started thinking about struts...

The pole length is as small as it can be.
 
I took a video to better show what's happening. I wonder if part of the wobble is the dish itself? It's much lighter than the CM so will be flimsier/more flexible...

 
Captain Jack said:
I took a video to better show what's happening. I wonder if part of the wobble is the dish itself? It's much lighter than the CM so will be flimsier/more flexible...

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I had a similar problem on my 1.2 Gibby of dish flexing from the dish mounting bracket, fitted top bottom and side struts which cured that. just took a quick shot of the dish in nearly dark sky but you can see what i mean.

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Dish struts.webp
 
John said:
I had a similar problem on my 1.2 Gibby of dish flexing from the dish mounting bracket, fitted top bottom and side struts which cured that. just took a quick shot of the dish in nearly dark sky but you can see what i mean.

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View attachment 164929
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Thanks John. Are the struts attached to the top motor bracket or the dish bracket itself?
 
Captain Jack said:
Thanks John. Are the struts attached to the top motor bracket or the dish bracket itself?
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Err can't remember to be honest CJ, i'll have a better look at it tomorrow in daylight and report back
 
John said:
Err can't remember to be honest CJ, i'll have a better look at it tomorrow in daylight and report back
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The back bracket on the 1.2 Gibby CJ is quite substantial so i made up a 3 way bracket to fix onto the back bracket for the extra dish rim edge supports - made an improvement to the stability of the reflector face for sure.

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Gibby 1.2 extra bracing..webp
 
That looks high up @John Fortunately I recently had the opportunity to move my cm1.2 to ground mount. I didn't fancy having to get up ladders as I get older to adjust dish or motor
 
Thanks @John - I have a few spare threaded rods, so will give that a go! Will wait for the winds to subside a bit first...
 
Manikm909 said:
That looks high up @John Fortunately I recently had the opportunity to move my cm1.2 to ground mount. I didn't fancy having to get up ladders as I get older to adjust dish or motor
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Looks like there's a view of the entire arc - especially being on the 1224 H-H motor.
 
Manikm909 said:
That looks high up @John Fortunately I recently had the opportunity to move my cm1.2 to ground mount. I didn't fancy having to get up ladders as I get older to adjust dish or motor
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Yep it is high up and yep it is a pain but i had no other option, i swear by the old saying "where's there's a will there's a way"
 
John said:
Yep it is high up and yep it is a pain but i had no other option, i swear by the old saying "where's there's a will there's a way"
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You must have really understanding neighbours. Mine have kittens every time I work on my dishes...
 
Captain Jack said:
Looks like there's a view of the entire arc - especially being on the 1224 H-H motor.
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Nah, unfortunately not on this 1.2m Gibby Ka/Ext Ku install, it can see from about 70 East to about 15West
** The 1.2CM install is on the main house roof, that goes from 71E to 71West unobstructed on the 1224.
 
Captain Jack said:
I took a video to better show what's happening. I wonder if part of the wobble is the dish itself? It's much lighter than the CM so will be flimsier/more flexible...

Click to expand...
You should be able to feel any play in the geardrive itself, especially if there is a noise.
 
There's very little play in the mechanism itself. Most of the play is at joints of the motor (and it's tiny play) but it translates to larger movements towards the dish.

I took some time off work this morning to modify the back bracket a bit to make it more "compact".. Not sure if it did much to the play but I like the look of it better. The "flanges" on the back of the bracket are for reinforcement rods (a la John) for whenever I get around to it.

I prefer the general "tidy" look of this setup than the monstrosity behind the CM dish that I had...
 

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Whilst tidier and compact, you will have to wait for a storm to see how stable the new gearbox is.

As befor I was surprised how little tightening was needed to fracture the clamping with mine, so didn't bother looking to repair.
 
Channel Hopper said:
As before I was surprised how little tightening was needed to fracture the clamping with mine, so didn't bother looking to repair.
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Do you remember which bit cracked? The alloy shell is light but has no give at all, so I am not surprised that it just shattered. I was thinking of packing any tiny gaps with washers or similar material...

Whilst tidier and compact, you will have to wait for a storm to see how stable the new gearbox is.
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I suspect that it's mostly aesthetic rather than it having an effect on stability... But every little helps?!
 
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Captain Jack said:
Do you remember which bit cracked? The alloy shell is light but has no give at all, so I am not surprised that it just shattered. I was thinking of packing any tiny gaps with washers or similar material...


I suspect that it's mostly aesthetic rather than it having an effect on stability... But every little helps?!
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It was the casting that bolts to the post, tightening one the - six ? bolts.

I'm sure the box and motor is still here, unused/unloved.
 
John said:
The back bracket on the 1.2 Gibby CJ is quite substantial so i made up a 3 way bracket to fix onto the back bracket for the extra dish rim edge supports - made an improvement to the stability of the reflector face for sure.

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View attachment 164937
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Blimey @John, I didn't realise how much the dish itself contributes to the wobble.

Take a look at this clip - it's filmed through the hole on the side of the dish looking at the brackets bolted to the dish. Some of it is phone movement but look at the bracket relative to the hole... wibble wobble. Don't have time today to fit the rods but I'll try this week while it's sunny.

 
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