Guys, thank you for kind comments.
I will certainly post updates on project progress, as it advances..
Quote:
Originally Posted by Tandum
bojan, I'm not sure what sort of finish polyurethane gives you but it might be worth while looking at a arcrylic render finish. Taulbmans armawall roll on render can be applied directly to styrofoam, no mesh, and gives a hard finish. It comes pre mixed in 15L containers and before application looks like really thick paint with .5-1mm stones through it. I applied it to mine with a trowel and once set, I gave it an acrylic texture top coat. Mine was hit by cricket ball a while back, leaving a small impact crater which I just slapped some top coat texture over to seal it. It's pretty tough stuff. |
Robin, thanks for comment - I will certainly have a look at that.
So, you didn't try to use any kind of mesh?
I was thinking, metal woven mesh may give me the additional strength in case of hail impact...
Quote:
Originally Posted by ChrisM
Bojan, that is going to be one very solid dome! Your choice of materials should provide a good measure of thermal insulation too. My 3V dome from plywood (without any frame) is very rigid - even after the aperture opening was cut. Some pics here http://www.iceinspace.com.au/forum/s...t=36222&page=2 (see posts ~#44)
Have you worked out the width of your aperture yet? Don't underestimate how far off-centre a GEM will put the scope! I'm almost on the limit for mine (at nearly 700 mm), but a narrower opening = more shelter for the scope and operator.
Looking forward to more progress reports.
Chris |
Chris, your work inspired me to take that challenge.. apart from a need to cut cost (pre-fabricated domes are terribly expensive).
The thermal insulation was something I thought of when I was browsing your thread couple of years ago.. when I was considering whether to buy or to build.
But those days I was working full time, and now I am in "forced" retirement (made redundant last year, and the job market for old, one-foot-in-the-grave RF engineer is very limited recently) - so cost became a major issue - and as at the moment I have enough free time to build myself, I decided to take that approach.
My opening will be 60cm wide - it should be enough for both for me and my 10" Newt, even at zenith (the eq centre-to-centre displacement is 34cm).
It will be a bit of the problem for synchronisation of dome and EQ and meridian flip, but this is something to be dealt with in the future.
For now, I am running a production of hexagons (using the template).. 13 + 2 1/2 are needed.