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4/05/2012

Northern Utah ATM Session: Building Shaun's Observing Chair

Ever since getting my 14 inch scope several years ago and my 20 inch scope, I have wanted to get a larger observing chair since my Starbound Chair is too small at zenith.  Now don't take me wrong, the Starbound Chair has been wonderful and works great with my 10 inch dob.  However, it doesn't come close with the 14 or the 20.  So I am going to post about the ATM project I am embarked on which is making my own observing chair with the help of my friend Mat. 

Early this year I almost pulled the trigger on the World's Greatest Observing Chair by Walt. When I was ready to do this, my daughter, who is now 19, but is still a relatively novice driver took her eyes off the road and drove her driver's side wheels into the curb, blowing both tires and messing up a few other things.  I fixed what I could and then had a $400 bill for new tires, alignment etc.  That took the chair away.  I had mentioned this to my good friend and ATMer Mat, who said we could build a chair.  So I started looking around and after a few models, I found Shaun's Plans from the Yahoo Group Observing Chair Group.  Those plans can be found in my Google Documents at this link.  Now if you decide to build this chair there are a few things you will need to remember, and a few things I or Mat can share with you from the experience.  First and foremost, on the plans, the front legs are angled backwards! Don't do what is there or you will have to re-cut the feet. We did that. Not a biggie but it took 3/4 to 1 inch off the height. Perhaps this log of building this chair will inspire a few others to do some ATM stuff.

First are resources.  What do you need? Mat has a table saw, a skil saw, a drill press, and two sanders.  Mat is graciously helping me and I am very much indebted to him for this.  You will need screws, glue and a drill to put the screws in.  In terms of material, I decided to use red oak since it was strong, a good hard wood and looks quite well.  I will write down here what sizes I purchased. I got my lumber from Lowes.  Cost was a little more ($20.00 or so) over a commercial lumber yard but the commercial lumber yard sold the sizes such that I would have had far more lumber than I needed.  The red oak from Lowes was already smooth and ready to go.  I spent about $90.00 to get all the wood for the chair. 


Today as I mention below I read that the chair built as the plans are, tilts the seat forward. Mat and I put the A frame of the chair together using clamps as you can see in the following image. The piece of the wood by the front leg is the piece we used to simulate the back. 








Next, Mat and I spent a day drilling the holes for the notches, and cutting all the pieces up.  When we were done I came home and did some researching and found that the chair actually tilts using the measurements because the beams that hold the chair in place are actually two far apart.  So today Mat and I took a look at the chair and put it together somewhat with some vices and we were able to see that this is true.  The chair slanted forward quite a bit.  Here you can see the first set of holes we cut for the dowl that will hold the chair on the notches and on the front piece.  They were to far apart. Mat brought them in by 3/4 of the inch, making the angle perfect!











So the angle was correct, but we found when we went to adjust the chair, the seat would not clear the notches to be moved.  In reading the resolution for the tilted seat it said we could use the table saw to cut off a blades width, or a use a plane to shave off an 1/8 of an inch.  Mat had a better idea and used his belt sander to sand off what was needed.  In this image you can see that we have taken off some of the edge using the sander.  The sanded piece is in the foreground and the leg/notches that are unsanded is in the background. 










This next image shows the reverse, with the unsanded piece in the foreground and the sanded piece is in the background.









We both noticed at this point, that we don't want to take anymore off the back side or we fear the notches will be too shallow to hold the dowel which will hold the seat in place. So we will be a new belt sander and will sand the front evenly to bring a little bit more down so the seat can move freely. 








The image above shows that we rounded the front of the seat holder and they are laying on what will be the seat.  The seat we are modifying and are using 3/4 inch plywood that will be covered in foam and old jeans to use as a functioning and comfortable seat.  Why jeans? They warm the dairy-air quicker than many other fabrics and they wear longer.  Plus when they do wear out it is an easy fix to replace. Find an old pair of jeans and there is the seat functioning again.

That is as far as we got on it and on Saturday, at Mat's monthly ATM meeting in his garage we are going to work more on it and get it really ready for assembling so I can coat it and the goal is to use it for first light on April 19th or April 20th (my birthday) which would be a great birthday present. So if you want to see how it works, come on out to Mat's.  Not sure where Mat lives, leave me a comment and/or email me a JayLEads at G M A I L dot c O M (put it together so I don't get caught in some hacker's program) and I'll forward it to Mat and he can send you directions.  If you want to see mirrors being made, telescopes being planned and worked on, a chair like mine being worked on, or a binocular mount come out.  


I have a couple of sketches from M45/Venus and of M42 that I want to share and will post them up this weekend.  Please, if you have wanted to get going into an ATM session come out, even if you don't think you have the skills. People are willing to help! Yes, you'll do your fair share of the work so you learn, but there is plenty of help!





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