Restoring a working antique dish to full functionality..

[Channel Hopper]

Non magnetic CH...
Been taking a look here https://carbonfibreprofiles.com/products/grp-rods
for £30 I could replace all 3 IF they were a metre long.
Sadly not the case as they are 41.5 inches (105.41cm)
I cant order custom lengths so would have to go up a size to 2m which at almost £19 each (16.2mm) diameter is both wasteful and expensive.
I havent even looked into shipping costs.
If anyone has some glass fibre rods around 16mm diameter and longer than 106 cm you have a buyer waiting.

Glass fire rods bend, but you said these are absolutely rigid.
It might be there is an aluminium centre (which would not be the antenna type unless for portable useage)

 

[Vipersan]

OK, VS, I see you want to go 16mm glass feedarms. Then take 3x1m, drill 5mm holes from at the ends and make internal M6 thread in those holes. Then take pieces of M6 threaded rods and fix them in the feedarms. On the attached picture I made a model to better understand the idea. If you get issues with the internal M6 thread, later you can enlarge the holes and thread M8 inside. View attachment 171089

Thanks for the suggestion Rima.
I've found a way to contact CarbonFibreProfiles by email and have sent this to them.
I'll wait to see what response I get if, if any before making any decisions.
>>>
Hello
I think maybe you could help me.
I am trying to restore a 1.8m satellite dish made in the 70s.
I only have one good feed support arm ...two if you include a slightly damaged one.
made from glass fibre.
16.2mm diameter would be fine for this but the lengths you sell are close at 1 mtre...but I need 44.5 inches (105.4cm) thus the 1 mtre lengths are too short and the next size up 2m are far too long.
Also this would make the cost of restoring very expensive.
My questions
Could you provide 3 glass fibre tripod arms of the required length ?
Cost is an issue so if you can supply them...an idea of total cost including shipping to me would be very much appreciated.
I am in Manchester M27
I appreciate this is not a from stock request...and a one time order.
Many thanks for reading.
rgds
E Parton
an old satellite enthusiast.
>>>

..you never know they may have some odd lenths / damaged stock ...

 

[Vipersan]

Glass fire rods bend, but you said these are absolutely rigid.
It might be there is an aluminium centre (which would not be the antenna type unless for portable useage)

I suspect these would shatter long before the showed any sign of bending CH...which is what happened to one of them.
Maybe there is something structural added to the resin during manufacture that makes them so dense and rigid....like a metal powder ?
I do think that 16.2mm diameter even without anything added would provide sufficient rigidity ..in that both the base and the apex are set into cast aluminium.
If I can get replacements cheap enough ..its gotta be worth a punt.
rgds

 

[John]

yep just popped bagged a green chargeable one for myself...
sod the expense.
lol

Mine arrived this morning VS, a very nice bit of kit ... i recon you'll like it

 

[Vipersan]

Mine arrived this morning VS, a very nice bit of kit ... i recon you'll like it

..as did mine John.
Certainly more accurate than the cat toy pen.
Already started the fitting to the plate.
Still some tweaking to do...a 20mm bore hole required in the plastic billet.
..and mounting such that the laser is as close to the plate as possible without touching ...from the back.
That long tail piece on the boresighter will have to come off..
Also appreciated the latching power switch.
pic 25 is the interesting one imo.
Some pix

 

[Channel Hopper]

I suspect these would shatter long before the showed any sign of bending CH...which is what happened to one of them.
Maybe there is something structural added to the resin during manufacture that makes them so dense and rigid....like a metal powder ?
I do think that 16.2mm diameter even without anything added would provide sufficient rigidity ..in that both the base and the apex are set into cast aluminium.
If I can get replacements cheap enough ..its gotta be worth a punt.
rgds

Ah, forgot to ask about taking a picture of the shattered end(s), which map provide clues.
16.2mm over 1.1m shouldn't be absolutely rigid with fibreglass products of the era.

There are alternatives out there

One moment, please...

Ask them how much to cut into four pieces for easier shipping

 

[Vipersan]

No reply as yet CH ...
I no longer have the broken leg ...but no evidence of a metal core on the remaining ones..
I'll try and get a photo ..but camera doesn't like flash exposures of almost black rod ends.
I'll have to wait for sunlight and turn off flash.

In other news...I found my final solution to trapping 23mm diameter ally tube in the bored out casting of the sacrificial bullseye lnb.
A 22 mm manganese circlip ....and a groove cut into the tube with shallow depth pipe cutter to mark/score a circle then a hacksaw blade to widen the groove and cut to a depth of 0.5mm all around the circumference.
This will enable me to 'trap' the circlip applying inward pressure with a custom made aluminium washer with a 23mm diameter centre hole.
I have yet to make this...but here are some pics thus far....

 

[Vipersan]

appologies for any double posts....the server keeps timing out on uploads...
damned frustrating as I have no idea which attempts made it.

Took a look at the link you provided CH ....sadly nothing either solid or hollow tube in the 15 > 16 mm diameter range...
..and £45 minimum transport cost is taking the piss anyhoo.

 

[Vipersan]

The rain held off and Nothing secured...but I just had to drop in the boresighter assembly for a quick photo-op didn't I..
The strings are still in place and easily visible where they cross
lol

 

[Channel Hopper]

Spinning the device keeps the beam in the same place ?

 

[John]

Spinning the device keeps the beam in the same place ?

Prompted by Big Clive, i can say that on the one i have it was really accurate when tested with rotation on a handy door frame with a target distance of about an lnb focal point setting

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[Vipersan]

Prompted by Big Clive, i can say that on the one i have it was really accurate when tested with rotation on a handy door frame with a target distance of about an lnb focal point setting

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As did the one I received ...so any deviation is introduced by myself when drilling.
Obviously since I dont have a lathe...just a drill press....this can happen.
But over a metre or so I cant see any problems.
Cant guarantee I could accuratly blind an airline pilot...lol...
..but I'm happy with it.

 

[Vipersan]

Interesting....
My mate just called for a coffee.
I showed him an original tripod leg....and the first thing he said..
feels like fibre glass resin....then he tapped it end on a paving slab.
His hearing is much better than mine...and his verdict was ceramic..
It rang like pot...
..and because of its ability to shatter...this was yet another indication of ceramic.
Not pure ceramic but a mix of ceramic and resin.
???
As to replacements ...another idea he had ...and I rather like this one.
A wooden former to keep a plastic pipe straight.
15mm plastic water pipe...and slow poured resin to fill it.
This could work imo.
I guess the problem would be trapped air bubbles...but 1mm holes pierced into the pipes length....and a stick like tamper...much like a musket back in the day.
maybe ..just maybe this could work ?

 

[Channel Hopper]

As to replacements ...another idea he had ...and I rather like this one.
A wooden former to keep a plastic pipe straight.
15mm plastic water pipe...and slow poured resin to fill it.
This could work imo.
I guess the problem would be trapped air bubbles...but 1mm holes pierced into the pipes length....and a stick like tamper...much like a musket back in the day.
maybe ..just maybe this could work ?

Before you get too creative

https://www.ebay.co.uk/itm/127233636320

Cut to length, bundle three around a piece of studding and bind each end.

Bob's your auntie !

 

[Vipersan]

So..what do you do when you want to reduce the end of an aluminium feed from 25mm dia to 23mm diameter ?
Enter poor mans lathe.
I've cut the c120 flange from the adjustable feed I recently aquired retaining as much length as possible ...so not just hacksawing off the flange but reduce it with a combination of right angled sawing with a blade then coming up with a creative way to suspend the feed in the drill press ...and using a steel washer as a limiter...plus a length of threaded studding...and a square 10mm file...
Its a slow process...requiring many coffee breaks...one of which I'm enjoying right now.
But like British Rail said decades ago....We're getting there.
lol

 

[Vipersan]

..That worked far better than I had any right to expect...
I will of course have to go up a size on the circlip idea.