So ya wanna build a pier; Wonderful idea, brilliant idea, I had the same idea meownself.
Some of you may not wanna tell your semi-old back what you are about to do!
I wanted a pier as I have come to understand that it saves setup time and makes for better accuracy.
But, we may move out east sometime in not too distant future and so I wanted to lessen the permanent pier factor, consequently I did not want to have to go to concrete pier as its permanency factor was high.
Also, semi-old, semi-retired, semi-stingy so was looking for something cheaper than what most astro companies are selling by way of steel piers.
So, while perusing the broadway of idea sharing on the web I bumped into a little thing called a Todmorden Pier. And then I found this site – A Pier in Our Backyard
http://popupbackpacker.com/a-pier-in-our-backyard/
Great site, great narrative of building a pier. So, using it as a guide I began.
The first step in my endeavor to image the sky better and more accurately was to remove two large pecan trees that were right in M31’s path. Squirrels still not happy but I promised to share photos with them.
I then waited ‘til evening and found the best spot to place the pier in my Bortle 8 backyard.
Next, dug the hole, about 18x18x18 inches. Took 4 50 lb bags of concrete to fill. Note the above comment about semi-old backs.
Following his suggestion, I put 4 anchor bolts in a 18×18 slab as the base to set atop the concrete. I made an effort to have the slab level and pretty well pointed to True North (3͗° 15” from magnetic North in my local).
24 hours to set.
I set three 8x8x16 concrete blocks upon which the mount would sit and glued and bolted them together. In hind site, and after setting the mount and telescope, I would have made one of them an 8x8x8 as the telescope tops out at over 8 feet now! I can work around it but if I do a second one (already have the materials) it will be 8 inches shorter. I would also suggest trying to do a pilot hole prior to drilling in the blocks as they ain’t the smoothest things to try to get an accurate hole drilled. And perhaps use a drill bit just a bit larger than the bolts for wiggle room.
Besides the metal pier most folks use, the adapter for the mount that sits atop the pier can be very expensive. As Nick mentions in his site, there is a cheaper and just as effective substitute – a car brake rotor; in the case of the Celestron CGX, a 2010 Malibu LS’s rear rotor. I bought one off of Amazon (ACDelco Silver 18A1675A Rear Disc Brake Rotor) for $33 and one from AutoZone
(Duralast Brake Rotor 5491) for $59. The Autozone fit just that much better. If I were more patient I would have gone to junk yards for cheaper still but, . . . this ain’t a cheap hobby any way you look at it and despite the lies you tell your spouse!
My brother had a drill press and so I headed his way and he and his son helped me drill the holes that joined the two rotors and the holes that joined the mount to the rotors. My brother had only SAE tap and dies and so we used that to drill and tap the holes to the rotor (a new skill I have picked up!). In hind site I should have sprung the extra bucks for a metric set and then been able to use the one set of screws. It works out because the holes in the mount are about the same size.
Nick suggests that if properly laid, the concrete, slab, and blocks should be level so no need for the elaborate “spider” system some folks have used to get the two rotors to level the mount. Mine was pretty level but not quite what I wanted to so I used pennies to achieve that last bit of leveling. I may try screws for just that bit more accuracy.
Put on the mount and then the scope. It is tall but solid. I have a border collie who wants to do astrophotography but she always tries to get me to image Sirius (for some reason) and if I don’t she barks and jumps up at the scope so I have installed a Canine Impediment Screen to keep me on the target I want and to keep her from imaging Sirius.
My hope and plan is to build a shed around it, possibly large enough for two piers. LORD willing.
I have so far shot M27 – the Dumbbell Nebula. The pier made the massive difference in set up time and tracking that I was hoping for!
I highly recommend this for you who are considering a pier.
The Text and the Telescope 