Building an Observing Chair ATMing with Mat
Unfortunately, I haven't had the pleasure of observing due to that wonderful condition know as spring in Utah. It is cold, in the 30's right now (yes, that is cold for April) with plenty of clouds, rain and moisture in the air. I woke up around 3:00a.m. and there was a sucker hold outside and I went out and looked at Virgo longingly. Hopefully next weekend is much improved!
So with the down time my friend Mat and I and my daughter Kendra have been working on my new observing chair. We met on Wednesday night for about three hours and worked on getting the notch arms connected by screw to the back. Here is my daughter, yes she has short hair and she is wearing one of her grandfather's old lined plaid shirts which are warm, drilling hold on the the notch arms to the back support. She did a really good job on this and it was fun having her along. Kendra likes working with her hands and with wood so it was a great experience for her. Next, she is going to grind a mirror and make her own dob!
We spend Wednesday working on the notch arms and the back and when we were done, we noticed that there were three minor splits in the back from having the screws in those areas too close to the edge. On Friday night we corrected that my putting in wood glue to the micro-fracture splits and you cannot tell where they were. We removed the screws in those areas and then re-drilled above them so the splits won't have any reason to split in the future.
After getting done we assembled the chair and both Mat and I sat on it and it held both of us. We did this to ensure we got the right angle for the chair. Above is the back leg.
Here is the chair with the seat on it as we sat on it. We used a wide angle on the feet here but you'll see from Saturday's picture the actual seat won't be spread apart so far I believe.
A close up of the seat and I offer that because the seat I took the cheap road on as I have mentioned in a previous post using 3/4 inch plywood that Mat had. I figured I am going to cover the seat so it doesn't matter. Mat thought about it and decided though for the bottom that we would use some corner acrylic (I believe) covering for the bottom which we ironed on yesterday. Mat's used it on his equipment with no problem of it coming off for well over 10 years now.
Here, in the light of day, you can see what the strips look like glued down to the bottom of the seat. This is not the top, but we'll flip it so this is what the bottom looks like. It allows for the plywood to more closely resemble the actual chair, though not too many people I fear will be looking at the bottom of the seat while I am sitting on it or someone else is! That would just be wrong unless we are trying to fix something. Looks great though and I am glad Mat thought of his. I am also glad to have Mat's help on this and he has been a tremendous help in terms of saving time. I owe him big time. He's looking for a 24 inch mirror blank 1 to 1.5 inches thick that isn't too costly if anyone knows of one, leave a comment please or email me at JayLEads at g mail dot com (put it together, it is this way to avoid spammers).
On Friday as I stated, we glued up the very small splits and that worked great so on Saturday we assembled the chair on last time and then started final assembly with glue. Here are the wedges, sanded down on the end being glued and screwed to the chair braces. The braces were needed to keep the angle of the chair correct since the plans were off somewhat.
One of the things we learned from Mat's neighbor who is a woodworker is that the notch arms had some space between them after we had screwed them down to the back. Mat's neighbor said that when we went to glue, to screw down the screw in the middle and work to the each end from there. That should eliminate the space. Sure enough, it did! Saturday then we glued the back leg, the two notch arms to the back and we put the bottom brace on using hanging bolts 1/4 inch with two wing knobs. I'll get a picture of that next time to show. This will allow me to take the bottom brace off and thus to easily take off the seat and transport the entire chair flat. I have Velcro and am going to make two Velcro strips/belts to hold and secure the chair for transport.
So, what is left? We'll, I have all the materials for the seat and we need to finish assembling the seat and glue and screw the actual seat to the supports. Then I need to put my memory foam, my foam and then I purchased a blue sleeping bag pad from Walmart and I'll cut that material to match the foam and put it on top to provide some support to the foam so I don't just sink to the wooden chair when I sit on the cushion. I am going to use a couple of my son's jeans that he has worn out of late to cover the cushion. I thought of a vinyl or something similar but I think that is too much money. The jeans provide a unique look and if I do the pockets right, I just may have a place to store some sketching materials!
After the seat, we have to redrill the holes for the foot rest and assemble that with screws and glue. Then we have to decide where to put the aluminum support, whether up high as designed or down low. I hadn't thought of this until now but if I put it up high I fear it may interfere with the movement of the chair up and down. I'll have to release the aluminum support, move the chair up and then reattach it. I got a 3 foot aluminum piece so we'll see and I'll talk to Mat and look at the chair.
After that I need to sand down the edges so they are rounded and not sharp, and apply five coats of my MiniWax Helmsman Spar Urethane to the chair. I am not going to stain it, I really love the natural color of the Red Oak. It could be stain, but I love natural wood like this so it is just going to get the clear coat. I figure I have another week to go on it and I fear in this week my new Zambuto mirror will show up and I want the chair done before I have to put on my virtual counterweight and perhaps one other counterweight on my 14 inch dob (which I'll document here). Here is a picture of the chair so far right before it got glued.
What have I learned from this? First and foremost having an active ATMer in the community like Mat who is willing to share his time, talents and tools is significant. People here in the Salt Lake area who want to make their own stuff need to get involved in his monthly ATMing. It saves money, I'll have well over $150 in the cost of the chair and more importantly, I know that I will have played a role in building what I am using and that brings a sense of pride. Secondly, it taught me that guess what, I at home, could do this IF I had to and more importantly, I am going to have to second think whether purchasing an Astro-Gear is worth it if I can make it myself. Third, ATMing is a blast. Good friends, good project, and you end up with something you've made yourself. I have to thank Mat again for his assistance, guidance, friendship and all that he has done, not just for me, but for many who are in the process of making scopes and other things. Next up will be a 4.5 and then a 6 inch mirror and then perhaps an equatorial platform for the 14 inch dob. Here are some links for doing that:
One more link to the AstronomyinUtah ATM forum where I've posted a lot of links for this:
ATM AstronomyinUtah Link
If your interested in trying out making a small telescope, I have an extra 4.5 inch mirror blank someone locally could work at Mat's ATM marathon coming up the first Friday and Saturday of May. Just let me know. Friday will be from around 6:00p.m. or when you get off work til 12:00a.m. or you get too tired and then all day Saturday from 9:00a.m. til 5:00p.m. or Mat kicks us out! In that time you should be able to finish a 4.5 inch mirror and then in June, build a structure for it and then get it coated. Nova Optical is right down the road from Mat and I and Steve can get it coated for you (see Nova Optical for costs or email Steve at that link).