Monday, September 24, 2012

Build Vs. Buy: Build for the Win!

My work has been a bit crazy lately, but I was fortunate enough to get some needed time off and spend several nights observing in Joshua Tree last weekend around the new moon.  The observing at night was great, once I get my photo's together and have a few free moments, I'll post a report.  During the day I had some time to compare some options and think a lot about my next telescope, and I've decided...


I'm going to build

Ever since the idea for this project really solidified in my head, I always imagined building the telescope I want;  Not from scratch, but by assembling the parts I hand picked.  However, I wanted to take a look at what's out there and make sure I could not get a better deal with a commercially available telescope.  Something already built that would fit my requirements.

To help make my decision, I took a look at all the parts that make up a telescope, so I could look at the commercial options out there compared with what I could buy.  It helped a bit to solidify what I was looking for in a telescope, and ruled out several commercial options (for more detailed look at each of these commercial options, check out this post from 10MinuteAstronomy):


  • Orion XTxx Scopes: There are several goto, and push to, scopes in 14 and 16" size from Orion.  Across the board they are just too heavy, and I don't really need the extra cost and complexity of the Goto/Push to.
     
  • Hubble Optics 16" ultralight dob: Price seems good, very portable, but the reviews indicate mechanical issues.  If I have to make a lot of modifications to make it smooth and stable, I might as well get something more solid right off the bat.
     
  • Meade LightBridge 16": Price is very good, but they are pretty heavy.  There have also been mixed reports regarding the motion and overall build/design.  It seems like with a bit of work these can turn out to be nice scopes, but they are still larger and heavier than I think are needed.
     
  • T-Scope, Obsession, StarStructure, et. al.: All very nice options, and they all seem like they could be configured to meet my needs, but I'm pretty sure I can assemble a scope just about a nice, and make some more specific decisions along the way, for less money.  


Additionally, I do like to work with my hands, and I'm sure I'd enjoy at least some parts of assembling my own telescope.


Assembly Budget

Part of evaluating commercial scopes, particularly the high end ones that seem to meet my requirements, was figuring out if they were more or less I would spend to build.  Armed with my broad list of parts, I fleshed out a rough budget.

None of these numbers are very specific, they represent average costs for the components I would need.  As I have time, I'll research each of these components and figure out which specific ones will work best for me and my budget.

ItemCostNotes
16" Primary Mirror$1400Based on JMI Primary/Secondary Kit
Secondary Mirror$0Included Above
Mirror Cell$250Multi Point Flotation Type Cell
Structure$700Based on Dob Stuff 13"-16" Kit
Spider$100
Focuser$200
TOTAL$2650

This assumes a 16" scope, which may not be the size I choose based on a recent experience at the Pacific Astronomy and Telescope Show (more on that later), but the pricing for every component except the mirror and mirror cell is valid for anything roughly 13-16".  In figuring out an ballpark price for each part, it was pretty clear that the mirror is both the most expensive, and the most variable component.

You can buy $500+ dollar focusers, and that would be two or three times the cost I budgeted, but the change to the overall budget would be only 11% or so.  Conversely, I might be able to save a bit of money if I build my structure from scratch, rather than buying the DobStuff kit, but it would not be much compared to the overall budget and I'm not sure it would be a good investment of my time.

The Mirror, however, is the big variable.  In looking around, the JMI option listed above was the least expensive option I found; The costs can easily go to double that price.  If the mirror were $2800, that would increase the overall budget by a whopping 52%!


Next Step: Mirror

If I'm going to try to meet my one year timeline, I'll need to eventually start purchasing stuff, and the mirror seems like the first decision to be made.  It's the largest component, cost wise, and it's size, weight and mounting will influence other decisions.  So I figured it's the component I should research and decide on first.

I've put together a preliminary list of manufacturers, but they are a bit hard to find and I expect my list is incomplete.  Please leave a comment if you are aware of, or have seen reviews for, any mirror manufacturers or suppliers in the 14-16" range.  I'd love to hear what you think.


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