The Orion project...
Posted 22 November 2012 - 04:30 PM
I had planned to just add some reinforcements to the XT12i base to get rid of the flex, and look for some magic mix of lubricant as well as maybe adding a laminate ring to the existing base, but I think I've decided to re-build the base from scratch entirely. (I'll re-use some of the existing hardware, but it'll be mostly a "from the ground up" project.)
The one thing that was keeping me from doing this, was I was a bit worried about being able to transfer the push-to Orion encoder/computer system to an entirely new base, but after really looking at the entire system, I think that's going to be a non-problem.
I've taken some starting measurements, and am in the process of putting together a basic plan, which I'll post as soon as I complete it. I'll also try to post pics of my progress/trials and tribulations. I'm starting this in the ATM forum since I'm guessing this type of thing is fairly small potatoes for you guys and gals. However, if I'm about to go down a precarious path at any point, some of you expert ATM'ers can give me a "FOR THE LOVE OF GOD MAN, DON'T DO THAT!!!"
I'll be moving somewhat slow on this though, since I'm kind of a "measure once, think about it for a while, measure again, think about it for a longer while, eventually cut" guy. Also - the scope is usable as-is, so there is no rush. I'm kind of setting an informal goal of having it ready for spring galaxy season.
Thanks in advance for any and all help and direction!
Posted 22 November 2012 - 04:51 PM
Posted 22 November 2012 - 05:14 PM
I've gone back and forth between doing an ground-up rebuild vs. a fix-it job, and I've kind of come to the realization that I think I might have a bit of fun going ground-up. I'm not going to ruin anything with regards to the original base, so humpty-dumpty can be put back together again if needed, and when I priced things out, it looks reasonable (famous last words, though).
Posted 22 November 2012 - 05:24 PM
Posted 22 November 2012 - 10:50 PM
Posted 22 November 2012 - 11:11 PM
The upper cage would hold the focuser and secondary assembly etc.
Has anyone tried anything similar?
Posted 23 November 2012 - 12:36 AM
The measurements I've included are ones I think are somewhat important to keep consistent with the existing base.
Posted 23 November 2012 - 08:29 AM
Posted 23 November 2012 - 01:34 PM
The base of my 6" f8 is 17 inches in diameter. I can't imaging putting a 12 inch on a disk that small. I'd say 22 inches is a minimum. Try to put the side walls of your rocker box above your laminate ring, rather than outside it.
That footprint seemed kind of small to me as well, but I was going off of dimensions I saw from Obsession's 12.5" rocker box. I've increased the bottom dimensions to 22"x22", which has also allowed me to put some "wings" up the sides like Orion does on their xx12, which should also help the flex problem.
Here's version 1.1:
Posted 23 November 2012 - 01:46 PM
Here's a difference in height between the original and modified Lightbridge base and the new one I'm currently working on:
Posted 23 November 2012 - 02:32 PM
Posted 23 November 2012 - 03:43 PM
Posted 23 November 2012 - 03:55 PM
It can be done easily. I adopted the Orion system to an Obsession. I mounted the encoders in plastic project boxes, attached an arm to the boxes, ran 1/4" bolt thru the hollow Orion encoder shaft. Then mounted them to the scope like standard encoders.
Really!! Now that is interesting! You don't happen to have any pics of your handiwork, do you?
Posted 24 November 2012 - 12:10 AM
Posted 25 November 2012 - 03:34 PM
Posted 25 November 2012 - 05:44 PM
Posted 27 November 2012 - 10:49 PM
I moved the front board in about 1.5", which (I think) will stiffen things up even more, and I've notched out the tops of the sides a bit after looking more closely at the xx12 base.
After considerable mulling, I don't think I'm ready to to a re-design with the bearing system at this time. Perhaps after I get my feet wet with this project.
I hope to be buying some plywood and making some cuts this weekend. (As long as temperatures don't plummet between now and then, as I'll be cutting in my garage and outside on my deck.)
Posted 01 December 2012 - 03:34 PM
I used a 4x8 panel of 3/4" birch plywood from Home Depot. I suppose I could have spent twice as much at a specialty wood shop on a higher grade, but I think my mediocre woodworking skills will end up being the "diffraction limited" part of this project, so I figured this would do.
Next, I'm going to take a leap of faith where I disassemble the original base, remove the encoders, and use the original base panels as templates for drilling holes.
While at Home Depot, I looked at some vinyl flooring samples. They sell smallish samples of a number of different types, but the sample size ends up being too small to cover my base board. Any suggestions for my source of Ebony Star-like laminate? I see I can buy the real thing from some specialty scope stores, but I was hoping I wouldn't have to spend near that much.
Posted 01 December 2012 - 11:18 PM
Original hardware and encoders bagged and tagged:
I used the original base pieces to transfer some important measurements to the new pieces:
On the laminate front, I see that there is a lumberyard in the area that deals Wilsonart (makers of Ebony Star) laminates. I've heard that Ebony Star is no longer offered, but maybe they offer something close. I'm also hoping they have remnants, as I only need a 2'x2' piece, and it looks like entire sheets run about $100.