Hi all,
I'm starting to work out my first observatory for my 12" Dob. Being in a farming district I see these mobile field bins around every harvest. I can pick up an old one for about $500, It would not be hard to put a door & a floor in one. Also because they have wheels for towing on the road, I wouldn't require a building permit at all. There weather & water proof as to keep the grain dry if it rains. What do you think?
I would imagine that the hardest part would be getting a stable floor to work on. As it is mobile and the shape it is I presume your floor would be at the lower junction of the outer wall and base cone unless you plan to remove that. Walking around it would flex the floor and creat vibration and movement problems. Dobs are usually used outside an Observatory as you need low walls to reach lower atltitudes.
I could see one being converted easily to a proper Observatory but it would have to be 'de-wheeled' and 'de-coned' and mounted at a permanent site. ( Send one over, I got ideas !! )
Can you elaborate a bit more on how you would do it please ? I might be completely off-track with my assumptions.
You pretty much said it all really, I was thinking of removing the lower cone, re-sheeting the lower section, remove the wheels or just block it up. Could put in a 3/4" ply wood floor & have a small solar panel vacating the air in the daytime so it won't get too hot inside. Being movable it could be turn around before each nights viewing. Also these hold 25-28 tons of grain, I doubt it will move with an 80kg person walking about inside.
Great idea Doug,
The other thought would be to hack off the top cone and add a track and some rollers between the wall and the top. That way you can rotate the top only.
Bo
Great idea Doug,
The other thought would be to hack off the top cone and add a track and some rollers between the wall and the top. That way you can rotate the top only.
Bo
I did consider this however until I can get inside one, it's all a matter of how there are built. The last thing I want is the project costing more than the telescope.
I've heard of floor roller rotating Obs but I think you would need to make it a permanent installation. The scope would have to sit on a flat isolated base. If the scope is on the same floor platform as the viewer, even 3/4 ply, it will move and flex.
My plan would be concrete base with sealed to ground low height inside roller wall ( 100mm maybe ) that acted as the track and also kept water out. Easy to motorise as well. But I'd be having an EQ mount on an isolated pier block rather than a DOB.
Bit more work obviously..
If it is for a DOB then outside walls need to be quite low. You may be able to cut off the bottom cone and drop it down to give 1 meter (?) high walls which should give you reasonable horizons.
Rotatable would need other options looking at, eg an internal low wall as I mentioned above.
Take measurements, lots of them. And some closeup pictures. Inside as well.
Cone height, outer wall depth, diameter opening dimensions, anything you can wrap a tape measure around.
Need to understand how robust the wall is or whether it would need bracing or whatever for rollers.
If it is just a welded plated steel sheet there will be a fair bit required to make it usable.
Well I had a closer look at the field bin and it's BIG. The second thing which is good is the lower cone is bolted on, so removal will be a cinch, so a lower level is a possibility because the bin is about 4 meters high. I haven't done a ground to peak measurement yet but that's a fare estimate. The top cone is also bolted on so modification to make it turn is also possible.
I will start drawing up a plan & see if this boat will float..
RAIN & more rain, all I've done is checked it for leaks, however It's bone dry inside. I've done my plan & it will cost $250 for the floor & an engineer has advised a 1" square tube frame around the aperture which will go from the roof down to the floor, this way I'll have views all the way to the horizon. The aperture door will be hinged on one side with an overlap to seal out dust & weather. The aperture frame may cost around $100 for labor & material. So the whole project may come in under $700.
One thing I didn't know when I bought it is, it has a trap door under the cone giving an easy entrance & exit point. The door is heavy steel & lockable. Lastly the wheels are raised or lowered via a canter-lever & turning the whole thing is very easy & takes less than a minute. As soon as it dry's outside I'll start taking photos.
)
