Sunday, 23 February 2020

DIY Steel Observatory Pier

DIY Steel Observatory Pier

One aspect of running a small home observatory, is to make best use of the space that you have at your disposal.  When I lived at a previous address, I quickly found the importance of having a permanent pier set up.  I wrote about the pier I made and posted it on the DIY pages of this blog.  The pier was made of two railway sleepers bolted together and then set into concrete in the ground.  
Some years later, at a new location and with the new observatory, I initially ran with the mount head sitting on the supplied tripod.  This was always going to be an interim fix until I created my own pier.
The footprint of the tripod is quite large which made manoeuvring around the observatory very tricky.  Not to mention the vibrations from walking on the floor shaking the mount and telescope hideously.  I kept accidentally kicking the legs which then affected polar alignment etc.  It just wasn't going to work long term.


It was time to put part two of the plan into action.  Back when I dug out the footings for the observatory, I created a concrete base to which I could retro-fit a new pier.  


With factory made steel piers costing anything from £500 and upwards, I decided that I would call in a couple of favours, source the materials myself and put one together DIY style.  Pier design is pretty basic.  Most are made of a steel baseplate, a cylindrical column and then some sort of pier head and mount adapter.  I saw no reason to deviate from these basic principles, although when trying to source a suitable piece of steel cylinder, I struggled.  I thought back to my old pier design using wooden railway sleepers.  The square cross section worked well.  It proved that the pier didn't have to be made with a cylindrical column. 
It's much easier to source square box section steel, and so I decided on 4 lengths of 100mm box section.  I could bolt 4 pieces together to make the column then weld that column to the steel plate base.


Given the success of my previous DIY pier, I decided to stick with the same principles for the design of the pier head.  I cut out some notches from the corners of the column which would give me access to attach the top plates.  I stuck to the same idea of using 4 threaded rods to form the pier head itself.  And then, of course, there was the recycled brake disk which I removed from my old wooden pier before we moved house!



So, all the component parts were now drilled, cut and fitted together.  It was time for welding.  It was during the welding process, I come across the only real design flaw which I have found.  And that was the thickness of the baseplate of the pier.  In hindsight, I should have gone for a steel plate of a thickness of around 10mm, rather than the 3mm thickness I went with.  During the welding process, the baseplate has warped slightly due to the heat generated during the welding process, and while the pier is still works perfectly well, it is an improvement which should be made if I were to repeat the process again.
Other than a couple of coats of red oxide paint, all I needed to was to drop the pier into place through the pre-cut gap in the observatory floor and bolt it into place with expansion bolts.  The final result now means that everything is mounted on the pier, without the spread out footprint of the tripod to trip over.  The pier itself has also provided with room on which to mount the control box for everything, and freed up floor space for power supplies.


So, to wrap things up, it might not be the most aesthetic of solutions, but does exactly what I want it to do.  I can now walk around the observatory, (in fact, I have had 3 people in there while operating the imaging rig!) without the concerns of vibrations shaking the mount and scope.  I haven't needed to re-polar align since the day I put it all in first and I now make full use of the park function on the telescope handset meaning that I don't repeat the star alignment process when I first start.  It save so much time!

3 comments:

  1. Thanks for this blog, have re read it since my new house will have a obsy in the garden. now to find a location that works..,..

    ReplyDelete
    Replies
    1. Hi, thanks for reading it. Sorry for the waffle though. I do go on a bit! The new obsy has made things so much easier and more accessible. 1 hour imaging sessions are now possible with ease, instead of having to spend most of that time setting up or de-rigging after. Now, shut the door and roof and leave it until next time :-) Never looked back.

      Delete
    2. One thing that I forgot to mention regarding the baseplate for the pier though. If I were to make another one, next time I would use thicker steel for it, perhaps up to 10mm thick. The steel for the baseplate I used did warp a bit during the welding process. The pier is still perfectly useable and sturdy enough, but a 10mm baseplate would do a better job. Clear skies!

      Delete