Restoring a working antique dish to full functionality..

[Channel Hopper]

If in doubt, hammer and vise.

 

[Vipersan]

Not perfect but overall I am pleased with how they turned out...
Having cleaned and degreased them ..the first coat of auto paint has been applied.
..giving me time for a spot of breakfast.
..paint hides a multitude of sins ie hammer marks
The wood former will provide a second function ..in that it can be used to correct that rim bulge on the right side of the Christine

 

[Vipersan]

Even such a small deformation could be contibuting to her deafness...
Hopefully I can coax her back into shape.
Would you apply heat CH ?or just keep winding the G clamps ever tighter ?
Shes had this bulge since I got her...obviously a problem from when she had a previous owner.
Now I have the wooden former I figured ..time to try and fix it.
C band is very forgiving KU not so much.
rgds

 

[Channel Hopper]

The wood former will provide a second function ..in that it can be used to correct that rim bulge on the right side of the Christine

Are you likely to have a go at a shakedown ? The former could be used in conjunction with string and visual LOS across the rim.

 

[Vipersan]

Are you likely to have a go at a shakedown ? The former could be used in conjunction with string and visual LOS across the rim.

Indeed I will give her a shakedown at some point ...but as I said earlier ...I rate it a 2 man job so I can only do the shakedown when my mate is available.
Not putting it off permantly but just putting it aside for now.
Like I said ..getting the pre shake jobs done first.

 

[Channel Hopper]

Crossed posts. Now I see what you are trying to achieve and yes, unless the reflector is straight all round, not all signal will end up inside the scalar. With many distortions on prime focus you may have two or more sweet spots when the should be just one (and an equal drop off all round).

I doubt just clamping will be enough as thick aluminium will have some spring in it, you would need to deform slightly further than the desired profile for it to return. Perhaps a bit of leverage with a piece of long pipe at the right spot(s) rather than a mallet.

 

[Vipersan]

Crossed posts. Now I see what you are trying to achieve and yes, unless the reflector is straight all round, not all signal will end up inside the scalar. With many distortions on prime focus you may have two or more sweet spots when the should be just one (and an equal drop off all round).

I doubt just clamping will be enough as thick aluminium will have some spring in it, you would need to deform slightly further than the desired profile for it to return. Perhaps a bit of leverage with a piece of long pipe at the right spot(s) rather than a mallet.

If you look closely at the wood former there a slight steps at each end of the curve which I didn't rasp out...so my theory is that the centre of the curve could be packed with shims or washers acting as shims to push the centre of the deformation slightly past the natural curve point achieving what you descibed.
If ya catch my drift.

 

[Channel Hopper]

If you look closely at the wood former there a slight steps at each end of the curve which I didn't rasp out...so my theory is that the centre of the curve could be packed with shims or washers acting as shims to push the centre of the deformation slightly past the natural curve point achieving what you descibed.
If ya catch my drift.

I did see the incremental tightening of the clamping screws, though not the former itself.

Did you keep any of Sheila's earlier giblets ? It might be wort checking the difference on each nearest the deformations on Christine for a pattern
(But a shakedown would be my first as you know, the current work could be a step too far and the issue just goes away.

 

[Vipersan]

So I guess that's all for today...
I left it as late as possible to allow the painted brackets to dry hard.
..but it is now too dangerous for me up ladders in the gloom.
All three brackets are on but only finger tight until tomorrow.
The top one you cannot see but the bolts might be visible.
a good days work imo.
rgds
VS

 

[Vipersan]

I did see the incremental tightening of the clamping screws, though not the former itself.

Did you keep any of Sheila's earlier giblets ? It might be wort checking the difference on each nearest the deformations on Christine for a pattern
(But a shakedown would be my first as you know, the current work could be a step too far and the issue just goes away.

sadly no I didn't keep any of Stellas gibbys ....except for the original extension panel wood and fibre glass mold ...just case I ever wanted to re-make those panels (doubtful now)...it's in the loft somewhere.

 

[Channel Hopper]

sadly no I didn't keep any of Stellas gibbys ....except for the original extension panel wood and fibre glass mold ...just case I ever wanted to re-make those panels (doubtful now)...it's in the loft somewhere.

Sheila is in the loft.

Understood.

 

[Vipersan]

Finally the sun came out ..and my coloured string had arrived so perfect day to string her up..
Ony done 2 sets of panels in opposition....red and yellow.
Still have to remove the former and clamps to do the last 2...and if any are really bad/far out it will be these 2 I suspect.
here are some photos of the process....and to be honest and considering age / wind / gravity etc...they are still pretty damned close.

Also got on order a 40mm diameter plastic billet to drill out and allow me to mount a laser pointer.
rgds

 

[Vipersan]

As I suspected Christines deafness is most likely related to the panel at 20 min past the hour.
an old injury which -MAY- be correctable..
The green string was put on last becuse I suspected it would ride higher..

rather than beat the panel back into shape I'm imagining a steel cable attached to the mid point of that panels rim ...the other end of which goes aound the mast/pole...and a come along hand winch to pull downwards and inwards. ?....something like this >>>>

 

[Vipersan]

I've started this thread in the hope that CH can move all my posts regarding Christine ..a 1970s 1.8mtr petalised dish to a seperate thread.
When he has time of course.
I appologise for clogging up the low SR thread ...but thats how it goes sometimes when a question becomes a quest.
rgds
VS

 

[Channel Hopper]

Time ?

 

[Vipersan]

Since this post isn't a continuation of anything else related to Christine ..I figured I'd post it in this thread.
The 40 mm diameter PVC black plastic billet arrived this morning..
Obviously an offcut from something larger but perfect for my needs.
So the most difficult thing was finding the centre ...and for this I first stuck a white label on one end..then used the 2 chord method with right angles at each mid point....thus where they crossed was as near as dammit centre.
Having marked this point I drilled out to about and inch with a 2mm pilot drill then used a 14mm wood spade bit about 3 inches depth as to allow a laser pen to slide inside...another 1/4 inch push depresses the on button and turns on the laser.
No gurantees of course of the central accuracy of the laser pen...but imo...close enough for government work..
here are the pics.
rgds

 

[Terryl]

Nice job Vipersan, I did almost the same thing but with a solid 3 inch diameter by 3 inches long piece of nylon, I used a wood lathe to make a piece like that for aiming a modified 3 meter dish.

 

[Channel Hopper]

Is there no way to install the laser at the reflector end ? It would save time.

For anyone wishing to try similar on a PF dish.

https://www.ebay.co.uk/itm/278395455491

 

[Vipersan]

It could be done CH ...put this seemed a better method in that it can be done quickly plus removed more easily .
In my case there is a removeable panel at Christines centre..though a flanged panel would have to be created that both centres and allows rigid mounting at exact right angles to the dish plane at the centre..
So yes ..of course it could be done but much more work involved...with less room for error.
..but technically once fitted it could remain permanent...since the laser would be in a permanent area of shadow beneath the lnb.
maybe I will consider this at some point.
rgds

Gotta love that bore sighter...
much more likely accurate than a cat toy..
lol

 

[Terryl]

They make a laser boar sighter for rifles, it runs on two "AAA" battery's and has a switch on the back so you don't have to get very creative, I have one for my .308, but after setting up the scope on it I hardly use it, only when I need to with a friend or someone that needs it done after a new scope.