But back to the wooden wedge that Rod’s friend built. In the book Mr. Mollise also said his friend had built a permanent pier for his observatory out of wood as well. There was a picture of the completed work but its quality was not very good. Being a member of the Yahoo group for the EQASCOM project I sent Mr. Mollise a message asking him if he had any better pictures of the construction of the wooden pier/wedge in Pats observatory. He informed he did not but sent me a link to the newsletter Skywatch in which there was an article written by Mr. Rochford detailing his plan and construction details of the wooden pier/wedge. This was indeed just what I needed as I was also planning to build a new pier for my Atlas mount/C11 combo in my observatory, Black Hole Observatory. The Atlas mount has been part of my astro adventures since back in the early 90’s and I am now on my second Atlas, the Atlas EQ G with the GOTO system. On my Atlas mounts had ridden a C8 very happily for quite a few years while I saved my coins to purchase a larger CAT. Well that day finally arrived in early May of this year (2013) as I ordered my C11 and waited anxiously for it to arrive. Of course, as with any new astronomy purchase it seems to bring cloudy weather and my case was no exception. I waited for about 6 days for the sky to clear so I could give the C11 first light, but that is another story. What I did find out on the night of first light was the pier that I had in my observatory was not quite “beefy” enough to handle the increased size and weight of the C11/Atlas combo. So I began to research options for a larger pier to replace the one I had.
That brings us to the main topic of the post. The building and testing of a wooden pier for a permanent installation in an astronomical observatory.
After making a few calls to plumbing suppliers here in the eastern KY area I was amazed at how much a steel pipe cost. For an 8 inch diameter steel pipe the cost was $29.00 per FOOT!!! I needed a section of pipe at least 40”s long as well as for someone to weld it up to plans I had drawn up. Total cost estimate was around $300.00 dollars and a significant wait time to get it all done. While waiting, my observatory would be hard down with no place to mount the scope/mount combo, as the person who was going to be fabricating the pier would need my existing pier for a template in order to get the hole spacing correct where it connected to the bolts embedded in the concrete filled sono tube under the floor. I also looked into pre-made piers from some of the venders on the internet and was amazed at how much these things cost. The least expensive I found was $800.00 and this did not include an adapter for the top plate to hold the mount!! So this was not an option for my poor pocket book. Plan “B” then was in effect. I went to a large home improvement store and purchased a single 4X8X3/4 sheet of oak plywood. I had worked out my dimensions and determined that the entire pier could be made from a single sheet. Along with the plywood I purchased all the hardware I figured I would need to put it together and make it as strong and stiff as possible. This list included 12 5/8” bolts, nuts, flat washers, and lock washers. I also got a pound each of 2 ½” and 1 ½” fine threaded drywall screws and a 1 pint bottle of Titebond III water proof glue. The stain and poly coating I already had so didn’t need to purchase these items. The total cost for this trip to the hardware store?? $116.00!! I now had all I would need to begin construction of my “wooden pier” ala Pat Rochford’s design idea.
The first phase was to cut all the pieces I would need out of the single sheet of plywood. This was made easier by the simple fact that the store would cut the sheet to my dimensions and only charge me .50 cents a cut. I had them rip the sheet into 4 pieces as my ripping skills are very much nonexistent. I am fine cross cutting on my table saw but ripping an entire sheet of ¾” ply was not in my best interest. I play guitar and really like my fingers.
Plywood ripped and hardware in hand I began cutting the ripped sheet into smaller pieces. The main pier column was to be 10” by 10” with a base of 20” square and 40” tall. My plan allowed for the base plates to be double thickness for a total thickness of 3”. The very bottom plate was painted black with a primer coat as this piece would be in contact with the top of the concrete. The other bottom plate was attached directly to the pier column and stained/polyied to match the rest of the pier parts. I also added double thick gussets to the sides of the pier column that were 20” tall and 4 ½” deep to provide extra support for the pier. (See pictures attached). All pieces were then glued and screwed together and then stained or painted.
While building the new pier, I realized that the existing pier was filled with play sand from top to bottom. Inside the new pier column I was going to add a stiffener plate half way up the column. If I wanted to put sand in the pier, it would need a hole in this piece, so I cut a 3” hole in the middle plate and then installed it.
In order to ensure a proper fit I would need to take the existing pier apart and mark the location of the bolts in the concrete. I waited for the very last to do this as I was positive the skies were going to clear up and allow me to test the new pier the very same day I installed it. Well folks, the pier was completely installed and the mount/scope was put in place on Friday the 28th of June and here it is July 1 and still no clear skies are in sight!!
So, for right now, enjoy the pictures and wish me luck with this endeavor as I await clearing conditions to perform my PA and put the new pier/mount/C11 through its paces.
Sorry this post is so long, but I thought it might interest those of us who do not possess the resources needed to purchase a “store bought pier”. My total cost including labor (my labor rate when I was employed was $20.00 per hour)? Right at $300.00 for all the pieces parts that went into the construction phase. I already had the power tools as I have always liked working with wood. I did need to purchase a forstner bit to drill the hole for the bottom of the Atlas to fit properly on the double thickness top plate. This cost me $41.00 and was not included in the above total as I will find other uses for it down the road. If you want to add it to the total that’s fine by me. I still was able to construct a pier for less than half what a commercial pier would have cost.
Oh, by the way, after getting it all put together, I thumped the side of the pier near the top and counted the settling seconds using a glass of water setting on the top plate next to the mount. It damped out in less than 3 seconds!! That’s without the sand as I am hoping I will not need to put any in the column. It’s very messy and makes it harder to take the pier apart should I have to move one day.