Elevated tower / platform for astrophotography

[900SL]

You could guy a pole using post tensioned rigging (like a yacht mast). Thus would significantly increase the stiffness compared to a freestanding cantilever. 

 

[Rusted]

2 hours ago, 900SL said:

You could guy a pole using post tensioned rigging (like a yacht mast). Thus would significantly increase the stiffness compared to a freestanding cantilever.

Much the same effect, but far less bulky, could be obtained by attaching [minimum 18mm thick] longitudinal, plywood ribs.
Like the welded piers but extending the entire length of the taller pole.
Glue is very unlikely to work on a pressure treated or tarry telegraph pole. BTW: These poles can stink depending on age.
Metal strap clamps make more sense for rib attachment. Even if it means cutting windows in the ribs to thread the clamps through.
Anything which projects from a pier is crying out to be caught by the telescope[s] at some point of normal sky coverage.
Remote operation would require cameras and monitors to avoid tangles or obstructions. 

[uhb1966]

On 16/10/2023 at 23:09, Rusted said:

Thanks. After a long running thread on my observatory build, on C&N, they finally got rid of me.
Because I kept mentioning H-alpha telescope mods in answer to queries. Which were banned from discussion.
I was using a 6" f/8 modified PST myself at the time. You can blame Peter Drew for that. 😉
Fortunately H-alpha telescope mods are discussed at great length by some very clever people on SolarChat!! forum.
Where progress and understanding of the safety, limitations and advantages of modding continues to this day.

 

@Rusteddont dismantle your obsy, it's the coolest we got on this forum!!!

[Rusted]

12 hours ago, uhb1966 said:

@Rusteddont dismantle your obsy, it's the coolest we got on this forum!!!

Thank you for the kind words but several, serious problems arise. This is not my thread so I'll try to keep it brief.
Though there is a warning here to others considering building high. Or considering building a plywood dome:

The 10' plywood dome leaks like a sieve at the joints: It is far too difficult and dangerous to apply GRP over the entire dome so far from the ground. Cherry picker + time + huge expense for materials. I no longer want the smaller, 10' dome anyway. The 2-storey building has already been enlarged to 4.3m Ø for the larger dome. The old [leaking ] dome has to come down before the larger one can go up. Which means crane hire. A larger top ring and rollers must be fitted before the larger dome will fit on top. The 4.3m dome is an unfinished project. Which means risking working on an unsafe dome high above the ground. My motivation is at rock bottom. So I am trying to give away the 4.3m dome and then dismantle the entire observatory.

[Mr H in Yorkshire]

1 hour ago, Rusted said:

The 10' plywood dome leaks like a sieve at the joints:

If you change your mind, and stick with the smaller dome there are some remarkable cartridge gun applied 'goo' products available these days, no need to GRP the whole thing, just seal the leaks. Not so easy to seal motivation that has leaked. All the best.

[Rusted]

Thanks. I used the most expensive "marine" quality cartridge sealer.
It was hopeless. Some kind of tape might have been [theoretically] better.
I don't know of any suitable for the job.

[Mr H in Yorkshire]

@Rusted I've been introduced to C-TEC CT1 adhesive/sealant by my local Dales Hardware/Agricultural merchants. They recommend it to all their customers as the best there is and they have never been wrong in their advice. It is pretty new on the market. I have now used it in a number of situations including polycarbonate to wood. It is definitely up to the recommendations. It comes in clear and a range of 'building' colours. I have no idea if it is available in Denmark.

[Rusted]

46 minutes ago, Mr H in Yorkshire said:

@Rusted I've been introduced to C-TEC CT1 adhesive/sealant by my local Dales Hardware/Agricultural merchants. They recommend it to all their customers as the best there is and they have never been wrong in their advice. It is pretty new on the market. I have now used it in a number of situations including polycarbonate to wood. It is definitely up to the recommendations. It comes in clear and a range of 'building' colours. I have no idea if it is available in Denmark.

Thanks. I'll do some homework on the C-TEC CT1 but it may already be too late.
It seems to be widely available over here at around £10 equivalent.

[Mr H in Yorkshire]

2 hours ago, Rusted said:

£10 equivalent.

It's about that much here. It's more fluid than many similar products. Should you use it, I found it best to wide mask either side, put down a bead then really squeeze it into the joint so that it grips/sets on all the interstices and irregularities. 

[Rusted]

1 hour ago, Mr H in Yorkshire said:

It's about that much here. It's more fluid than many similar products. Should you use it, I found it best to wide mask either side, put down a bead then really squeeze it into the joint so that it grips/sets on all the interstices and irregularities. 

Thanks.

 

[8324689]

Thanks all for the replies 

sorry I was away for a while.

 

I haven't given up hope!