Go Back   IceInSpace > Equipment > ATM and DIY Projects
Register FAQ Calendar Today's Posts Search

Reply
 
Thread Tools Rate Thread
  #1  
Old 10-03-2012, 06:52 PM
Keltik's Avatar
Keltik (Trevor)
Canis Major, Canis Minor

Keltik is offline
 
Join Date: Oct 2011
Location: Melbourne
Posts: 98
Carry-On Thread from the "Surplus Shed" thread...

....being my continuing saga of trying to build a refractor based on a Surplus Shed 127mm achromat. The Surplus Shed link saw me coming to terms with the fact that I had purchased a whacking great lump of refractor glass, and scratching my head as to the next step.
Deciding that too much head-scratching might lead to baldness, I tried sourcing a suitable cardboard tube that may provide a decent housing for the objective. The search was relatively futile. None of the local (Melbourne) companies bothered to reply to my email enquiries, and anyway, I was in some doubt as to whether I really wanted cardboard as a tube medium. I hate the futility of trying to apply screws to media that simply disintegrate with wear.
So: off to dear old Bunnings, who would surely post negative quarterly figures if I ever stopped visiting.
I came home with three 1.0 mtr-square woven fibreglass mats, and two cans of acrylic and catalyst. And attached is the progress.....
Attached Thumbnails
Click for full-size image (scope.JPG)
36.3 KB57 views
Reply With Quote
  #2  
Old 10-03-2012, 06:57 PM
Shark Bait's Avatar
Shark Bait (Stu)
'ZZ9 Plural Z Alpha'

Shark Bait is offline
 
Join Date: Dec 2011
Location: Brisbane
Posts: 1,017
This is true DIY.

I am looking forward to seeing the progress of your refracting scope.
Reply With Quote
  #3  
Old 11-03-2012, 02:19 PM
Keltik's Avatar
Keltik (Trevor)
Canis Major, Canis Minor

Keltik is offline
 
Join Date: Oct 2011
Location: Melbourne
Posts: 98
After a good sanding back, I put another thick layer of acrylic to fill out any tiny pits...nice shiny-looking finish, another very fine sanding and it should be ready for a few coats of gloss spray...
Attached Thumbnails
Click for full-size image (IMG_0104.jpg)
187.3 KB46 views
Reply With Quote
  #4  
Old 18-03-2012, 08:07 AM
bojan's Avatar
bojan
amateur

bojan is offline
 
Join Date: Jul 2006
Location: Mt Waverley, VIC
Posts: 7,112
Hi Trevor,
I am very keen to find out how your lens is performing.. both visually and photographically.

Long time ago I obtained 125mm dia, 616mm FL achromat (previously used in ~100 years old astrograph) and went through substantial effort to mount it into OTA.. only to be disappointed with it's performance (not that I didn't know it wasn't good for today's standards - I only didn't know what "bad" means in this case because the warning I've got was not accompanied with any numbers nor test pictures).
Now I have a tube which may be suitable for Surplus Shed lens - if it proved to be significantly better..
Attached is the test photo, crop from the 100% scaled frame made with my lens stopped down to F8 (at full aperture it was useless... this way it is sort of OK (for photometry, for example), but not suitable for "pretty pictures" applications)
Attached Thumbnails
Click for full-size image (JewelBox_col.JPG)
42.8 KB19 views
Click for full-size image (616_F8_test_coma_UL.jpg)
4.8 KB14 views

Last edited by bojan; 18-03-2012 at 09:38 AM.
Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 01:19 AM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Advertisement
Bintel
Advertisement
Astrophotography Prize
Advertisement