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DIY Portable Temporary Observatory


datman

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If you are looking for a heavier and waterproof material try:-

Welcome to the Bags 4 Everything online store

They made some black canvas screens to fit to my balcony - complete with brass eyelets.

They are fully opaque and do a wonderful job keeping out an annoying street light and the neighbours' outside courtessy lights. They attach to aluminium TV aerial poles using a combination of short heavy duty tent guy rope rubber bands and cable ties.

The balcony is ready for the scope in about 5 mins!!

Your portable obsy is really looking the business and I am looking forward to seeing the completed version.

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Had a go at the coverings today. I decided to make the 4 x 1.5M tarpaulins into one long one. Duct tape to hold the sections in place before sewing (yes as well as astronomy and metalwork I am fully trained seamstress and dress maker, if anyone is interested I do a natty line in green tarp). When I tried to remove the duct tape it was trying to lift of the tarp covering! So looks like Duct tape alone may work.

I also had a flash of inspiration why use the observing window as the personal entrance? Set the window stretcher to suit the telescope then cover the lower part. I will use a side panel as the entry which will be about 5' 3" high.

I loosely fitted the tarpaulins and discover a design feature ;-) If the upper eyelets are fitted with a length of 6mm shock cord (I used string here) when it is drawn tight it holds the tarp up on the roof at just the right height!!!! Needs a few more eyelets too.

The shock cord (bungee rope) could also be used on the lower sections to hold the structure together.

N.B. If you decide to have a go at something like this be very careful that you have the correct arragement before glueing. It is very easy to get fittings in the wrong order.

So here is the first fitting.

attachment.php?attachmentid=75364&stc=1&d=1323955643

This shows what will be the entrance I think I will make some sort of hinge arrangement to make a door. The viewing window is to the right as can be seen in previous pics.

I put the top sheet on just to see what needed to be done. As shown the scope would be looking South.

I need to see if the scope can see Polaris just by turning the Obs. 180 or if I need to have an opening in the very top of the roof.

attachment.php?attachmentid=75365&stc=1&d=1323956115

Next Post may be a few days away quite a bit to do and stuff to buy.

datman

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Really impressed with this. Just the job for a lightweight shelter

Are you proposing any means to tie it down? Only wondered because I had a mary poppins type vision of it floating away in the current storms!

Keep the posts coming though... a great alternative to the roll off roof.

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Really impressed with this. Just the job for a lightweight shelter

Are you proposing any means to tie it down? Only wondered because I had a mary poppins type vision of it floating away in the current storms!

Keep the posts coming though... a great alternative to the roll off roof.

I'll have to see! It can't go backwards very far there's a 6' bush to one side, the conservatory to the other and a 2' wide path behind it. I could always nail it to the decking ;-)

I wouldn't use it if it was super windy and it will only take a few minutes to remove the tarps. The frame won't go anywhere.

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i made a greenhouse in the same way. but to hold on the clear plastic i used some of the same tube used in the build to make snap clips.

cut the tube into sections around 4-8 inch long, then cut a slit down each section. pull covering taught then snap the clip over tube and covering. makes it quick and easy for you, a little more tinkering and a couple nuts and bots you can cowboy a hinge from a couple snap clips and have a door with snapclip catch

you may find stitching together causes the tarp to tear after a while.

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i made a greenhouse in the same way. but to hold on the clear plastic i used some of the same tube used in the build to make snap clips.

cut the tube into sections around 4-8 inch long, then cut a slit down each section. pull covering taught then snap the clip over tube and covering. makes it quick and easy for you, a little more tinkering and a couple nuts and bots you can cowboy a hinge from a couple snap clips and have a door with snapclip catch

you may find stitching together causes the tarp to tear after a while.

Thanks I'll try that, although this is 3mm wall tube not so sure it will snap over too easily but it might slide over. I have plenty of bits left to experiment with, I am looking for a way to make a door this could be it.

The tarpaulins were very cheap, I didn't really know how I was going to cover it. I'm onto design phase 4 at the min. The sewn tarps may have to be unsewn. Once I get it right I may well buy heavier grade stuff.

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dont want it to snap over to easy. my build used 10mm internal diamiter tube, just cut a couple test pieces and differnet width slits after a couple trys you will find just just right. imagine the profile of the clip as a C and this clips over your main tube. use the same tube used in build this way you get a nice tight clip and grip. to tighten the sheeting just twist the clips round the pipe, this will tighten the sheet slightly.

use a snapclip and a couple nuts and bolts to hold it to the door, then clip onto door frame, a little grease should help keep it free to swing. maybe sew the tops section so it can slip over frame and snap clips around base to hold it on.

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that looks great, when I saw it It reminded me of the very early c a r p fishing bivvys from the early 80's, did a google and found this cover which may be of interest to you.

FISHING UMBRELLA COVER-TENT/BIVVY,****,PIKE,COARSE,NEW. | eBay it will be more expensive but much more durable.

When I had one I sewed velcro straps to the inside to attach to poles to make it more rigid which would work with your frame.

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dont want it to snap over to easy. my build used 10mm internal diamiter tube, just cut a couple test pieces and differnet width slits after a couple trys you will find just just right. imagine the profile of the clip as a C and this clips over your main tube. use the same tube used in build this way you get a nice tight clip and grip. to tighten the sheeting just twist the clips round the pipe, this will tighten the sheet slightly.

use a snapclip and a couple nuts and bolts to hold it to the door, then clip onto door frame, a little grease should help keep it free to swing. maybe sew the tops section so it can slip over frame and snap clips around base to hold it on.

Hi

I tried the snap clip need to take out about 1/4 then it works, might apply a bit of heat to releave some of the stress when it's open. I've figured out a way of making a door using tees as hinges, The snaps may well come in handy for holding parts of the cover.

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Hi

Just to let you know I haven't died of xmas pudding poisoning and to answer the last post. After a number of experiments I've come to the conclusion that the best method of hanging the tarp is like a wigwam but not having American indian descent it took a while for me to figure this out. This will be done with 2 tarps (I have had to order another and am awaiting it's arrival). These cover the entire structure but not the observing window and will leave the square at the top of the roof bare. This will be covered with a 1.8 X 1.8M tarp which can be easily moved if I want to look straight up.

I have put extra eyelets into the tarps and will use mainly bungee loops (100mm) to secure the edges (Velcro might work but Bungee loops are readily available). The long bits of shock will be used to hold everything together and reduce flap. I have made a door at the front using 2 x tees as hinges. This is now permanently covered using bits from the tarp I messed up and bits of spare tube as clips as suggested by Tamiya Cowboy, it needed about 1/3 removing to make the clip "soft" enough.

The roof trusses were not quite right, using the base and middle as the jig was not the best way because the jig was too stiff and allowed me to fit tubes that were a bit too long. This is why the middle stretchers were popping. I could have left them as they were but......

The wheels are now fitted and the 2nd tarp is in the post so hopefully I should be able to take some pics of the finished project soon.

I have done some experiments with the telescope and with the tripod sort of central it does most things fine, turning the observatory 180 gives a sight of Polaris through the PA scope but not the telescope itself. If any objects are a bit high I can either fold back the top tarp or "bump" the whole observatory so it gives more clearance over the scope. It's not heavy and easy to move.

With regard to "stealing" my idea, it's not mine and even if it was I would be more than happy to share construction techniques and other detail.

I have more or less completed a Howto which explains how to go about designing one to suit your own needs. It is not a set of plans but has diagrams explaining how to workout dimensions etc. I need to update it to show how to make the door. I could also add the pics I have taken for extra clarification

If you want a copy PM me.

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Here is my first attempt at dressing the observatory. I haven't got the bungee loops yet so it looks a bit loose. Although it's not as tight on the frame as the first try it is much more functional. The top is held by ties holding it to a length of bungee that goes around the inner part of the roof.

The new tarpaulins a only a bit heavier 80gsm vs 70gsm but the material is much darker and reduces stray light much better. You can see here it looks quite dark inside.

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To get the folds correct I put in 3 extra eyelets between the existing ones at the back corner and 2 extra at the front corner. I put one extra eyelet between all of the others

The door cover is held by clips made from spare tube, these were much too tight and I had to ease them using a hot air gun. PVC is thermoplastic so once it cools it's just as springy.

post-24509-133877710887_thumb.jpg

There are 2 pieces of shock cord going all the way around this helps to keep the tarp in place and it does tighten the whole thing up. When I try to move it now it feels like one structure.

I also did some research on loose joints and was suprised at how little it takes to make a loose joint. Approx 1" of electrical tape on the end of the tube made a good fit. Tape all the way around will not fit!! Wiping the tube with a bit of solvent glue also works but is a bit more hit and miss and if you get it wrong you can't take it off.

The top will be held down by more shock cord going to the base which will also help to control the big tarp. These covers were a bit thin so I've used 2.

I will use a similar piece to cover the front when it is not in use.

This shows how the top cover is fitted. I also put a piece of wood across the top of the frame to support the cover in case it rains. The top is 2' 9" x 2' 9" so there is a good possibility of an overhead water storage system forming!

This was pointed out by a friend. I will make a properly shaped one when time permits.

post-24509-133877710898_thumb.jpg

Finally got the hang of inserting pics just in time for one last one of the finished job.

Now where did I put that telescope?

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That's a very clever use of proprietory bits.

When I started out on my first obsy I decided to bite the bullet and buy a MIG welder for about £150. Getting the hang of a decent, if scruffy, joint is remarkably easy. Well, this investment has proved to be worth its weight in gold. I've made four observatories with it, two large garden tables, several benches and an observing seat along with railings all round the sites, etc etc. Plus loads of little sundries out of mind.

Just a thought for those reading the thread.

Olly

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That's a very clever use of proprietory bits.

When I started out on my first obsy I decided to bite the bullet and buy a MIG welder for about £150. Getting the hang of a decent, if scruffy, joint is remarkably easy. Well, this investment has proved to be worth its weight in gold. I've made four observatories with it, two large garden tables, several benches and an observing seat along with railings all round the sites, etc etc. Plus loads of little sundries out of mind.

Just a thought for those reading the thread.

Olly

Thanks,

Yes MIG and even more so No Gas MIG are probably the easiest welders to use. In a former life I built a Ranger Rover based Off-Road special with one. Although if I had the room to build a permanent obs. I think I'd try a wooden octagon.

PVC tubing is probably the easiest material I have ever used and you could build the whole thing with hand tools.

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Finally completed. Each time I try I find a better way of doing things. Tarpaulin held in place by bungee loops and cord. I haven't used it for real yet but a quick try last night with bins was very satisfactory.

There is plenty of room inside, my c130 looks lost in there.

To answer one post about wind, it was left for a few days when it was very windy. it moved about 6' but did not blow over. It will be very easy to anchor to the decking.

I've ordered a tarp that will cover the roof and observing window when not in use. This will fold back over the top and be held by bungee cord.

So unless I get questions this should be the last post , did I hear a bugle?

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Fantastic job!! I really can't believe I haven't seen someone making this before? It seems so obvious once you've seen it!

I think you'll find you will be starting a trend on here! Peoples signatures will now include.." Datman Observatory" :(

Well done! Hat off to you!

Michael

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Well as I've already mentioned it's not my idea I spotted one like it on the internet. I just made my method of construction available to anyone else who wants to have a go. I believe in sharing ideas.

Just tried it out, bit cloudy so didn't stay long but very pleased, had a quick look at Jupiter and the Pleiades before it clouded over. I can fit a fold up chair and could probably squeeze a computer in there. However the plan is to route cables through the window into the consevatory for computery stuff!

Can't detect any light from the house or anywhere else.

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Do you think you would use it truly portable i.e. to take to dark site and use?

What do you think the total put up or take down times are?

I personally would not but I won't take me either (age thing).

If I were younger I'd say definitely if you were going for long enough. I'd say in it's easiest to transport form it would only take about 20 minutes to put up. It would need a couple or 3 lengths of bungee cord around it and a couple over the top to hold it all together. The tarpaulin is more of a problem depending upon the wind and how clever you are at fixing it. Depending upon your transport you could glue some sections together (2 stretchers would be about 2M long.

If you were going to a star party or something I think you'd need about 10'/3.1M size then you could live in it too. Wouldn't be much harder to erect the frame but that's alot of tarpaulin!

I intend to leave mine up unless the weather is really bad then I'd take the tarp off. I'll take it down in the summer.

This was the best compromise I could get given the size and location of my garden.

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