My name is Philip Matchett and I’ve been involved with the NIAAS/EAAS for over 20 years. Most of the time, I’ve been on the committee, I’ve held the roles of Chairperson, Vice- Chairperson, Treasurer and Webmaster. In all my time in the NIAAS, our main aim has always been to get people to look at the night sky.
Don’t know if this is true but it is told, Bill Gates once said, ‘If I have a difficult task needing done, I always get a lazy person to do it. As they will find the quickest and most efficient method to complete it’. I guess I’m a lazy person, as when it comes to observing, I just want to get right to the observing bit as quickly as I can.
How many of us have looked outside in the evening and seen a nice clear night and said right let’s get the telescope out? The process is then as follows:
– Get some warm clothes on
– Get the keys, open where ever the telescope is stored
– Start taking all the telescope equipment out, Tripod, telescope, power supply, cables, hand controller, dew shield/heaters, weights, eyepieces, chair, table
– Assemble all components
– Switch on and align
– Wait for telescope to cool to current temperature
– Realise that it is now cloudy
– Pack up and go in!
A lazy astronomer is an astronomer with an observatory!
One thing I’ve always wanted Northern Ireland to have is an observatory that people can go to and actually look through a telescope. Most astronomy societies in England have their own observatories, but none over here. Sure we have organizations, Armagh has the planetarium and observatory, but unfortunately both these close their doors when it starts to get dark. A few years ago, big news, the OM Dark Sky Park and Observatory was being built, but yet again, what a disappointment, not open at night and “no you can’t look through our telescope.” Will Northern Ireland ever get somewhere like Kielder observatory in England? Who knows, but read on… maybe in mini form?
So let’s roll back to June 2021, I received an email from a lovely lady in Scotland, it read: ‘Hello, I wonder if you have any interest. My Dad died recently and one of his treasured items was an Celestron 2800mm f10 telescope. Do you know anyone that would be interesting in buying a telescope? I can supply photos, etc should anyone be interested. Thanks Heather.’
Now, I have to say it’s not unusual to get emails like this to the society and between Stevie, Jonathan and myself we follow up on each and every one. What happens a lot, is someone has died and the family is left with, normally a large item, that they don’t know anything about and they want it out of the way. We will then, either pass the information on to someone who buys the scope or basically Jonathan buys it.
At first glance I didn’t see anything out of the ordinary with this email, and from the information given, I had very little idea what the telescope actually was. I followed up on the email and to my surprise it turned out that this telescope was a vintage C11 Black edition from around the mid 80’s, early 90’s. Now these are not small telescopes, they were created to be an entry level observatory telescope and this one was exactly that, housed in its own observatory! My ears pricked up.
Things to watch out for when buying a second hand telescope:
– Where is it located
– What age is it
– What make is it
– Does it mechanically work
– Does it electrically work
– Are the optics in good condition
After several emails back and forth to Heather, we decided the best thing to do was go have a look. Obviously our main concern was the age of the telescope and surely the optics won’t be in a good state. I told her that I may be more interested in the observatory as I was thinking of getting one myself. So myself, my father and Jonathan all met her at her family home in Dundonald. Sitting in the garden all by itself was this small shed observatory and inside it was this huge telescope on its tripod. As you can see from the pictures, Heather’s father was a proper amateur astronomer. What also transpired was the previous owner was a bit of a genius and liked to engineer his own bits and bobs. Jonathan and myself were in dreamland, exploring all his gadgets. So what about the telescope? Actually it looked very clean and the optics looked surprisingly good, considering the age. It also had basic electrical motor guidance and that also looked to be running. Onto the observatory, basically a 4 sided wooden shed with a flat Perspex roof that was built on a quite substantial metal frame that extended over and into the overgrown hedge, and then ran down the side of the garden. This frame allowed the roof of the observatory to roll off and move out of the way. We decided to see if it would work, Heather was very doubtful as she said it wouldn’t have been opened in a very long time, but with a little push it rolled off the observatory very easily.
Heather and her sister in their fathers observatory in Dundonald
The Celestron 11 name plate
My father and me, trying to figure out what we’re about to get ourselves into!
In my conversations with Heather and the family, I told her that to actually sell the telescope could prove extremely difficult. Based on its age and size, its age being of the generation that was before the internet, actually finding out much information on these telescopes proved very hard and when it came to size, who would actually make use of this, it certainly wouldn’t be a telescope to take in the car to a dark site and set up. Also how good actually are these optics, as I write this, that factor is still an unknown.
It was certainly impossible to put a price on it.
Heather agreed that it was more important for the telescope to go somewhere that if possible and still up to the task, would make someone happy and be put to use again.
With that… the foundation was set in my head to do this for them. I told them I would take the telescope and the observatory and try to get it up and running again.
Over the next month, my father and myself spent quite a few days back and forth to Dundonald, dismantling and transporting the telescope and observatory to its new home.
So what came next? I need an observatory.
What do I know about observatories? Well not very much to be honest. As far as I can tell, I had 2 options, buy one or build one, oh and where am I going to put it, relevant question that one. So, location, I live outside Antrim town. I’m out in the country, but not far away from Antrim Area Hospital; Dark Skies?, not too bad, not perfect by any means, but not too bad. So location…. back garden check… trees yes…we’ll deal with that later.
So observatories? Didn’t I just say I took one down in Dundonald? Well yes, but sometimes when you take things down, they don’t always go back together the same way. So I made the decision, if I’m going to do this, I want to do it right and I want it to be a reasonable size so more than one person can enjoy an evening comfortably under the stars. The one in Dundonald wasn’t very big, but I still have plans to use some of the material from it, recycle and all that!
Two main types of observatories are:
- Dome Observatory, the type you all know the look of, you see them in all the pictures on the mountain tops and you may have seen them at Armagh.
- Roll off shed roof, these are by far the most common observatories found in the amateur astronomers back garden. In fact there may be more of them around than you know as they just look like a normal garden shed. That’s one of the benefits, keeps away thieves, although I doubt very much that there is much market in stealing astronomy equipment!
So what choice did I make? Well I have to say that I was leaning very much towards the roll off shed roof type. There is somewhat a market for these over on the mainland and they come in all shapes, sizes and options. You can have a dry room, or the whole roof can roll off on a frame, or just half of it. Or even the sides drop down to allow the telescope to come out and play. Or I could buy a professional dome type observatory, these also can be purchased from the mainland. Now you may have noticed that we live in Northern Ireland and when I’m talking about purchasing I’m saying mainland, or another way of wording it is ‘just charge me double’. Yes as many of you are aware, if you are buying something large to come over this side of the water, you will pay for it. Especially when it comes to observatories, these also come with people to build them and that costs a lot.
I do remember a company over here that were manufacturing domes a while ago, however after searching for them, it seems that they are no longer in business. I guess, not really surprising as it is a very small market.
Can he build it? Well yes I guess I can. I’m an electrical engineer by trade and I’m not bad with my hands. I do seem to have any tool required for any job, however actually finding that said tool can somewhat be a battle!
So research time, google is your friend. Can I just say at this point, that sometimes I find the more you research something, the more conflicting and confusing the subject gets. Observatories fall into this category. After many hours on google and joining groups on Facebook with people all around the world building their own observatories of various shapes and sizes, losing the will to live, I came across this article on the ‘BBC Sky at Night Website’ LINK: https://www.skyatnightmagazine.com/advice/diy/how-to-build-a-home-observatory/
Mark Parrish decided to build his own dome observatory and has recorded how he went about it, complete with pictures and drawings and all documented on this website.
I liked the design, I liked the design a lot. I actually really liked all the information Mark put in on how to build it. I read the complete article and downloaded the supporting material and decided, I could build that!
Now before I go any further, as I’m typing this into my computer at 0045 on Sunday 31st July 2022, I haven’t built it yet. It is in progress, and as you’ll see as I continue the story, things are moving along, in fact I hope to have the concrete poured for the pier on Monday, BUT… disclaimer, when I said above ‘I could build that’, well the jury is still out!
Marks design was a 3 metre diameter dome and building, having measured this out, I decided it wasn’t big enough. I want bigger, how about upscaling his design to a 4 metre diameter dome and building, let’s do that.
Let’s have a look at a suitable location. So observatories generally have a good view to the south, after all this is where all the action takes place as the seasons change. One corner of my garden points south, it also is one of the areas furthest away from the house.
So what are the advantages of locating it here:
- Southwardly horizon
- Furthest away from the house
- Area large enough to locate a 4 metre building
- Close to electrical consumer unit to be able to run power cable easily
- Garden on a slight slope
- Horizon obscured by trees and overgrown bushes
Conclusion, happy enough with the location, garden at a slope and horizon obscured by trees can easily be dealt with by the design of the observatory and some industrial gardening!
Time to build.
Visit to the local hardware store and 10 large sheets of 12mm ply purchased. These are to be used to make the frame for the dome. First job was to make the dome circle, needing 2 of these, one for on top of the observatory frame and the other for the bottom of the dome assembly. These two rings would be separated by rollers that would allow the dome to rotate.
Easy enough to make as the outside diameter was 4 metres and the inside was 300mm less, making the width of the circle 150mm. The thickness of these rings is to be 24mm so that will be 2 layers of ply.
Obviously the sheets of ply are not big enough to make these rings in one go, so they needed to be cut and glued/screwed together to make the circle. What also became very apparent quickly was, a 4 metre circle is very big and I didn’t have a work area big enough to build this in. So the whole dome is going to be built in sections that will be put together later. We also don’t want the ply to get wet/damp as this would cause it to warp and fall apart.
First cut out of the ring, laid on the ground for sizing
I cut these quite happily over the winter months. Then it came to making the rest of the dome. At this point after studying the cad drawings Mark had done, I started to notice some discrepancies between the drawings and the pictures that were taken. Some of the dimensions on the cad drawings didn’t make sense and match the pictures. Some of this could easily be explained as sometimes when you design something and actually get to build it you may decide to stray away from the original design. This might be the case here and the CAD drawing not updated after the build. My dimensions were going to be different anyway as my observatory was going to be bigger, plus Mark is obviously a joiner by trade and as I’m an engineer, I have some different ideas on how to do the design.
Because my dimensions are different, I needed to work out what they needed to be when it came to the rest of the structure of the dome. I needed to do a CAD drawing.
Philip learns CAD.
So I did have some previous experience with CAD, but not much, mostly just navigating around it and making some small changes. Certainly not designing something from scratch and also, and this is a big also, not much experience at all of 3D CAD! Firstly, I needed CAD software. Did you know that you can get CAD software for free? And not just a budget version, actually something really powerful and from one of the biggest names in CAD software, Autodesk. The software is Fusion 360. You download the software but it actually runs online. This actually means that the large calculations that may be required can be completed on the Autodesk servers and you don’t need a really high spec computer to run it. Fusion 360 is available for free to hobbyists and not for commercial use, although it comes with some limitations, it will do everything and more that I will ever need to design the observatory!
Next step, how to use it! Fast forward many hours of online training and YouTube videos and I can mostly use it now. What I learned really early on, Dome design is actually not straight forward, in fact it’s probably one of the hardest shapes to design a frame around. It took a good few attempts until I actually got something that seemed to resemble what I wanted to build. Why don’t they just make them square?
This took forever to get the CAD drawing to look like this
Back to building.
Now that I had my radius’s and angles all figured out, it was back to measuring, marking and cutting more plywood to make the frame of the dome.
Now that the frame was mostly cut out it was time to head back out to the garden. Firstly some extreme gardening. Let’s see if I can get myself a good horizon. Chainsaw out and lets cut me down some trees.
Trees and high hedges cut down along the back wall. Grass cut well down and marking out started
Now that that is done, time to mark out the ground for the observatory frame and most importantly the base for the pier.
Some sort of weird symbol has appeared on the ground
The observatory frame is to be made with 8 100×100 posts positioned at equal distances around the circular dome. These posts will be there to hold the ring of the dome, the sides (fence panelling) and the floor of the observatory. They need to have a good solid foundation as they have quite a load to carry. My dad is good with a welder, so we decided to use some of the metalwork that came from the observatory in Dundonald and make post holder spikes from it.
Medieval torture devices
Me trying to figure out how to make this device start again
Rather, than just drive the spikes into the ground we decided to put them in holes filled with concrete. The pier base is to have a hole in the ground measuring 900x900x900, yes, almost a cubic metre. This was a lot holes in the ground to dig, so we decided it best to hire a hole drilling machine for a day! Still a bit of hard work but we got it done.
We mixed the concrete and got the 8 metal post holders positioned into the ground.
Posts in the ground, power cable ran in
Next, the pier. So I decided to go with a solid concrete base and pier. I managed to acquire a couple of metres of twin wall drainage pipe 225mm inner diameter. This would be submerged into the hole mentioned above and concrete poured around and inside it. But before we could add concrete, I also needed to install 4 M12 stainless steel rods and I decided to add a 40mm plumbing pipe in the centre for running cables to the telescope. I built a wooden template that would hold these items in the correct location while the concrete was being poured.
The steel rods were heated and bent by 90 degrees a couple of inches from the ends. These are going to be buried in the concrete and will help them hold in place.
Monday 1st August 2022, mixing day. Shortly after 11am we started the mixer. The mix was 3:2:1 ratio of stone/sand/cement. Myself, my father and my son, 3 generations were about to build something that was going to be in place for a very long time and as I told my son, you are going to have some fun when I’m gone trying to get this removed! The wheelbarrow started the journey back and forth from the driveway at the side of the house, across the garden and being tipped into the large hole in the ground. 3 hours later, and after constant level checking with a spirit level, the monster was created! The mixing gods were on our side today, just after we finished the last mix, the mixer broke down.
Well, that isn’t coming out of there anytime soon!
We’ll just let that cement set now! See you in Part 2!