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Garden Pier for my Telescope

 

I have been given a 100x100x2400mm (4"x4"x95") timber pole. With this I finally decided to construct a temporary pier for my telescope in my back garden. I can now leave my mount aligned between sessions. This will save me a considerable amount of time setting up my scope and leave me with more observing / imaging time between clouds. Laughing

My mission was to construct everything with materials that I already have. No money was to be spent.

Starting point: one pierless garden and one massive timber pole


One hour later the hole had been dug out. The width and length are the size of the spade and it's about 60cm (23") deep.

Then I've cut the pole to 130cm (51") which leaves about 70cm (28") of it above ground.

Next I drove 8 bricks around the pier between the timber and the walls of the hole using a piece of timber and a rubber mallet. This will hold the pier in place.

Then I filled the gaps with about half of the dug out soil (more like clay and chalk than soil, really). I kept compressing it with a piece of timber and a mallet as it filled up. The top layer almost looks like concrete. Wink

Here is the view from inside the house. You can also admire my rather unobstructed view in all directions... Foot in mouth

Then I constructed a pier adapter for my CG5-GT mount. This is the bottom of the mount which needs to be attached to the top of the pier:

So I took another piece of wood and cut 2 rings with 2 different sized hole saws. One slightly bigger and one slightly smaller than the required diameter.

And removed the wood between the rings.

Then I added a "North Bolt" to polar align the mount with.

Next day it was time to mount the pier adapter on top of the pier.

When trying to put the mount on the adapter I realised I needed a bit of extra height around the rim of the mount. So I cut some piece of ply into shape.

Now it fits nicely.

The mount is secured in place by a long 3/4" BSW bolt that I happened to have.

Then it was time to put the telescope on top of the mount and see what it looks like. Not too bad I think...

The above photo also shows a mod I did earlier. A 50mm finder guide scope mounted on a big, solid B&S camera mount. With the B&S mount it is far easier to find a nearby guide star than with guide scope rings. And with that small, lightweight finder it doesn't move when tightened. The camera is one of my LX modded Philips SPC900.

And finally, this is what it will look like most of the time.

I do realise that this pier will eventually start rotting. The timber hasn't been treated at all. The idea was for this to last about 1 year until we buy a house and I can at last build a proper observatory.

I got lucky the night after I finished the pier. There were still a few clouds but the gaps between were big enough to allow me to align the mount and check if everything works. The pier is a lot more solid than the tripod.

I had tried my best to make the pier vertical. This wasn't easy as the bricks in the ground determined where the pier was pointing. I managed to get the East-West almost exactly straight (the Wixey shows 0.1 deg to the West). However, the pier does lean to the South by just under 2 degrees (Wixey shows 1.9 deg). I think this can be compensated for with the altitude adjustment bolts of the mount. This would not be possible if the pier was leaning East or West.

As usual, many more pictures of the build can be seen here:
https://picasaweb.google.com/117034922665750406576/201108GardenPier#