Hello fellow Instruct-ables... What better way to celebrate space than to look at it through a really big telescope? I have been an ATM for quite a while and this is my latest project, a big refracting telescope on a big mount.
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Signing UpStep 1: Gathering Parts
The mount is made from mostly easy to find scrap parts I found on line. I spent a lot of time looking for scrap pieces that were close to sizes I needed until I found that the metal merchants would cut pieces to size for pretty cheap. I used common power tools such as a small drill press, router, circular saw and chop saw. Working with aluminum is a lot like working with very hard woods, the cutting feels the same but slower.
The chassis is made of 1/2" sheet aluminum. The bearings are pillow block bearings. The Main(RA) shaft is 2-5/8" diameter aluminum and the smaller(dec) shaft is 1-1/6" steel. The large worm gear was purchased cheaply from an astronomy website.
The chassis is made of 1/2" sheet aluminum. The bearings are pillow block bearings. The Main(RA) shaft is 2-5/8" diameter aluminum and the smaller(dec) shaft is 1-1/6" steel. The large worm gear was purchased cheaply from an astronomy website.
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Hopefully my wife will let me spend a little more time in the shop now!
Sean
Do you know of anyone that has used a section of the heavy Green plastic sewer pipe which is available in diameters starting at 10 or 12 inches for this?
I have found the white PVC pipe locally that is 8 inches approx. in diameter.
Anything 6 inches or less is available in the plumbing supply / home improvement stores .
The problem is that once you get to the green commercial PVC piping the gets buried underground a ways , it also gets very heavy as the wall thickness is quite thick as it is schedule 30 or 40 so it won't crush when buried in the ground.
The Blue PVC underground piping is for water mains and has an even thicker wall on it than the green sewer piping as it needs to be schedule 80 and be able to take the municipal water pressure continuously .
If you know some one in the business and can get thick-walled PVC, go for it. You won't find a cheaper easier-to-work material and you won't have to go to the gym again ever!
Once the lenses are installed into it the tube I am very sure that the weight of these sizes of lenses won't be very light either.
I figure that it is going to take 2 people to set the scope up of that size on site anyway.
The ground or earth base , the mount system and then the scope tube and other parts will need to be assembled in pieces to be able to handle them .
In theory it could be "portable" with some work involved with the set up.
If you were going to make it portable and transportable what length and diameter of tube would you consider to be a maximum for such a project ??
What would a person use to anchor the thing into the ground without a hard pad to set it on?
Perhaps 3 of those large 36" or 48" tent spikes with plates welded on the ends that could be leveled ??
Would that give a steady enough base to install such a powerful telescope onto without worrying about vibrations etc.??
What kind of clock drive system would be best for tracking the stars OR moon for these larger scopes ??
No joke: when I started to get a feel for how heavy this thing was going to be I started lifting weights and doing back exercises so I wouldn't kill myself lugging it around. I have to drive about 45 miles to get to dark skies so the scope travels a lot. So far, no major issues but I hesitate to go larger/heavier without permanently installing it in my yard(not possible at this time)
With a scope as large as you suggest, a clock drive of 12" or better would be minimum, they get pretty pricey if you buy them off-the shelf. Last time I looked they ran from $900 to around $3,000.
If your scope is of Newtonian design, I would suggest an "Equatorial Platform"
Easy to construct on your own with good enough tracking even for basic photography. Google it to see what they look like.
Thanks,
Sean
Just saying.
Most of us do not live way out in the country .
But your point is well taken and I am sure that someday "someone" would come up with an instructable for building a stationary observatory facility at home.
Are you game?
I wonder WHAT the building inspection office will tell you when you go in to get your building permit for such a facility ,LOL .
How are you going to make it rotate to track the stars?
There will be all kinds of other structural questions they will ask of you.
They will probably tell you that you cannot design it yourself and you will need to get the service of a qualifies architectural and structural engineer.
I KNOW our building inspection office would tell ME that .
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I set out with this project to prove that you didn't need a full-on engineering degree to make an accurate large mount. Frankly, Imprecise is my middle name, I measured very little during this project. It was more important for the parts to be square with each other rather than specific sizes.
Everyone's access to materials is different all over the world. One of the largest homebuilt refractor's (a dialyte)is in the UK with an objective of 32" or so. During the first year I was gathering parts, no dumpster was safe! I remember measuring pipe in my restaurant's basement for a pier I was thinking about mounting the scope on!
let me know and perhpas it will be for you. 2 scopes and crappy needs reapirs tripods. free for experimentals on LI.
Drop me a line through instructables and I will put you in touch. These will be free, but you gotta go get'm
PVC. Short lengths = Flower pots.
Split lengthways = Vegie Garden.
2 X 2 meter lengths makes 44 Gal US water tank.
Fan in one end & cut out in the middle makes a Wind Tunnel for testing model aircraft wings.
Have fun.
Author unknown
I like the minimalist design of yours. I camped next to an 8" f15 once at a star party and it's huge size made me decide on a 6" for myself... Who made your lens?
Best Wishes.
Hope you will bring it to the Prairie Skies Star Party!
Sean