Tuesday, 13 September 2016

South horizon hatch video

I've now got the linear actuators attached and working on the south horizon hatch. When the hatch closes it locks the sliding roof in place and stops it moving sideways or vertically. The actuators have positional sensors so they both move in unison and each is rated at 2000N so both can roughly hold 400 kg force or something very close, this means they have enough holding force to resist strong winds and gales. I still need to fit the limit switches and write the software to open and close the roof and make it ASCOM compliant.

Monday, 12 September 2016

First images with new mount

Got a few images using the new mount, starting to look better. Need to sort out the electronic focus and auto guide next.

200mm RC on EQ6
Cannon 1300D
30s stacks
all around 15mins exposure

Saturday, 3 September 2016

Homebrew EQ6 pier

After a bit of looking and searching around I figured that I could make a decent pier form a post hammer. These things are made from thick steel and are well constructed and cheap. I also needed a top plate for the EQ6 to mount onto. I realised that the inner part of a car wheel would fit just perfect.. (These are also called Post Rammers and Post drivers)

After a bit of investigation I worked out that the top of the EQ6 mount could fit onto to the inner section of a car wheel. The plate normally has three legs attached but by using some carriage bolts bent with a right angle in thing they line up perfectly with the wheel holes! On the right is the section cut out from the car wheel.

I also fashioned a new bolt which would also grab the bottom of the pier as well as the four bolts giving me five points securing the EQ6 head to the pier. Left is the old bolt and right is the new bolt made from M12 threaded rod with a section ground to remove the threads. 

The post hanner had the handles removed, the wheel section welded to the top and some new tabs welded to the bottom for bolting it down. I also cut a hole in the side to allow me to put my hand in to access the bolts.

This is the finished pier ready to get bolted down and accept the mount.

All done! Well one scope anyway.

Thursday, 1 September 2016

Roll off roof mechanisms

If your planning to build a rolling roof observatory the one piece of advice I would give above all else is don't skimp of the rolling mechanism. Make sure you get some decent steel castors and rails. I initially used some big nylon castors but it wasn't great. Get decent steel castors like those used for large sliding gates/hanger doors. The roof here is around twenty suqare metres and weigts quite a lot, I used 6 large quarter ton rated casters with built in ball race bearings. The rails are made from sections of angle iron welded together sitting flat with the angle side pointing up. The result, I can move the roof by pushing it with my finger.

Saturday, 27 August 2016

Video of roof rolling open and closed

Video of the roof rolling open and closed again on the new castors and steel track.

Friday, 26 August 2016

Single frame images testing 1300D

Some images testing a new setup, the mount was not properly polar aligned but wanted to give it a quick test. Will get it mounted on it's telescope pier soon.
NEQ6 mount with 8" RC and Cannon 1300D
All images are single frames 120s @ 3200 ISO

M27 - The Dumbbell Nebula is a planetary nebula in the constellation Vulpecula, it was the first planetary nebula to be discovered by Messier

M13 - The Great Cluster in the constellation Hercules

Vega, the brightest star in Lyra, it's relatively close at only 25 light-years from Earths

Heavy duty steel roller getting fitted

Fitting some heavy duty steel rollers for the roof. Each one has a in built ball bearing.

Tuesday, 16 August 2016

Roof plastic sheets fitted

The plastic roof sheets are all fitted. Took longer than I expected over 500 fittings! The sides are starting to fill in as well.

After moving the roof a few times I decided to get some metal wheels and runners for the roof. The wheels are 80mm diameter 250Kg V-groove pulleys with ball bearings.  Each track will be made from angle iron. These will hopefully make a more friction free system.

Saturday, 13 August 2016

Rolling roof frame in place and rolling.

The wood structure for the rolling roof is now complete. It seems to roll quite well. For now it is using ten rollers, each capable of handling 100kg. I'll see how it performs over time and if it starts to degrade I'll swap to a metal track similar to those used on sliding gates.  You can see that the roof sits about 300mm above the rest of the structure. This is so the entry door can be normal height and also means the scopes don't need to be parked at odd angles to avoid the roof.. The South side of the building (farthest in picture) will have a small section of the wall than can be folded down to allow visibility to the horizon.

Wednesday, 10 August 2016

First roof truss

This is the first roof truss, it's sloped at 15 degrees so has a maximum height of 600mm. I picked 15 degrees as I didn't want the roof to be too height but have enough of a slope to cope with the weather. The base is 4800mm as this will allow an overlap on each side of the building. l just need to another four of these now.

Monday, 8 August 2016

Rail supports and exterior cladding

The main support beams that will carry the rolling roof are now in the right place, they are currently sitting on temporary supports. The proper supports will be finished later on and then the beams will be cut to the correct length.

Two of the exterior sides are now clad, I want to get the walls sheeted and painted so that I can start to weather proof the structure a bit before the roof work starts. Being Ireland we do get a good bit of rain and if the walls are clad it means I can at least use a temporary tarpaulin in place of the roof.

I've left room on one wall for two small windows. I don't want the structure to heat up excessively during the day so I'm keeping the windows to a minimum. The exterior will be painted white for the same reason.

Saturday, 6 August 2016

Progress with walls and piers

Wall frames are getting along fine, three now complete. I also got the three telescope piers cast in concrete. These are the bottom of the piers that are anchored solidly to the large block of concrete foundation under the floor. When the formers are removed there will be a gap all around each pier to isolate it from the main floor.

Friday, 5 August 2016

First side wall frame complete

The first side wall frame is now finished. This wall and the opposite one will also become the rail for the roll off roof, so they are quite sturdy. The top piece of wood is another 45x145 joist as it will support the roof. Each vertical consists of two pieces of wood so that the top rail is resting on a solid bit of wood and not relying on fixings. It was easier to use two bit of wood rather than order several thick posts, but posts would work just as well you would just need to slot the top of them to accept the rail. I also made a few 45 degree braces to ensure everything stays vertical. When I was finished fixing the wood together minus the 45 pieces I used a block hammer to get both diagonal measurements equal ensuring it was perfectly square, then I fitted the 45s. I'll post some more detailed plans of the side wall later on.

A few more detailed pictures below :-

Plans - Floor

I'm posting some basic plans for the floor layout here.

The main design is to have the floor completely isolated from the telescope piers and foundations. If you take a look at the posts on the telescope foundations you will also see that this has a barrier layer of sand and gravel below it and also all around it to try to isolate it from the surrounding ground as best as I can. The telescope piers will protrude through the floor via openings but will not come in contact with it. So people can walk

The floor is resting on two long concrete foundations which run the length of the building and the joists span the entire span between them. For this reason the joists are quite thick C16 grade 45mmx145mm and spaced approximately 400mm apart.

Thursday, 4 August 2016

Putting down the basic floor

The main floor that the rest of the structure will be built on top of is now finished. When the inside is being completed this will be covered again with a cheap laminate flooring. The sheeting used for the floor was 1.2mx2.4mx11mm OSB. It's cheap, strong and easy to cut with a circular saw.

I made sure that when the sheeting was going down there were lots of trap door panels left that can be lifted later for access under the floor to allow cable runs to the scope piers. There are also three openings for the main telescope piers as well, for now they are covered to stop me falling down them. Cross braces were added between the joists at each edge of the openings.

Some more photos below.


Sunday, 31 July 2016

Floor joists finished.

All of the 12 flooring joists are now in place. The joists are 45mmx145mm (6"x2") and are spaced 40 cm apart. The end joists are fixed to the concrete foundations with angle brackets using concrete bolts. Each joist also is resting on a strip of thick damp proof membrane. There is also a strip of 24mmx75mm (3"x2") running down each side to keep the joists in place. I painted the joists with wood preservative as they might get wet. The OSB flooring panels are getting fitted. Each one of these also has some trap door sections cut out so that I can access the underfloor later for running cables etc.

Saturday, 30 July 2016

Telescope foundations nearly done.

Today we managed to get about half of the telescope foundations cast and finished, all that remains is a final pour of concrete. Below is a few photos as the day progressed.

1. Digging finished, using a flooring joist between the foundations to keep a level.
2. Here the hole has been filled with a layer of gravel and sand, this is part of the vibration isolation to keep the slab out of contact from the ground.
3. I had an old wall I wanted to get rid of as well so I'm using the old blocks as part of the foundations as hardcore. I have placed a few bricks vertically so the two layes of this concrete pour are solidly joined. You can also notice that around the outside there is a barrier of gravel and sand.

4. A very wet mix of concrete has been poured in to fill all the spaces between bricks.

5. Everything is ready now for the final our of concrete. I will be starting to build the floor before the pour is done. I have to wait for more concrete so I don;t want this to keep me back. I will be able to pour the concrete into the mould that is currently sitting there. You can also notice the layer of sand and gravel around the very outside.