I also thought about stretching the pipe to 11.3cm and cutting grooves in the tube so that I can fit the assembly in, but I don't know if this will work. Just a thought. By the way I am going to try and get the pipe to 12cm before I look at other tubes.
Just looking at the above, and wondering if your making the mistake I made initially with the 80mm. The long end of the objective mounting with the ridges is where the dew shield fits. The other end fits inside and over the tube. (assuming the construction is the same as the 80mm)
Just checked the pics and it looks like you have the cell wrong way round just like I did.
Looking good Phil
I used small self tappers to hold my 80mm together rather than rivets, which was just as well as I had to adjust tube length a bit once I got the final focuser and 2" diagonal fitted.
Looking at Phil's set up I think I have put it the wrong way . This will make thing much easier thanks for correcting me. I've never owned a refractor before so I'm a complete novice.
I checked the SS website, & this is how they say it orients. The lower end has an ID of 109mm. Although it does look kind of counter-intuitive.
Following Bill's suggestion, I just went back on the site to double-check. It says: "The mounts smaller diameter side is meant to point to your object or the sky and has a diameter of 112mm (OD) and the larger side (bottom) has an ID of 109mm, OD of 116mm and an outer flange with a diameter of 127mm."
So the way it is in my photo definitely conforms to this spec (both dimensions & flange). But of course, it could still be wrong! I will drop them an email today just to confirm.
Last edited by PhilW; 16-02-2008 at 09:08 AM.
Reason: added info
Happy to help Christian. I had mine completely assembled by the time Omaroo pointed out the error. It does tell you on the web site ad, but I'm one of those people who only reads the instructions when all else fails
Instructions? What are they? I would have been kicking myself if I went to all that trouble and it was the wrong way. All I need is a focuser then and I'm ready to assemble. Thanks again
I like the idea of using self tappers (not that I've ever made an assembly error you understand ). Although with rivets you can just drill them out & re-rivet the offending part. I like the riveted look on my binoscope, it has a couple of kilograms of them.
Cristian, I have a spare focuser if you're interested in having it. It is cheap & basic, but it does the job for these little scopes. PM me if you want it (free).
Phil, I initialy had a plastic focuser on mine (SurplusShed el cheapo) but changed it for a better one and added a 2" diagonal. Then found most of the eyepieces wouldn't come to focus (not enough inward movement) so had to shorten the tube. Thats why I'm glad I used the self tappers.
OK, I have the OTA together & it is all working. I realised I made the dew shield incorrectly once I saw Bill's comments. It needs to fit further down the cell over the flanges & not at the end the way I have it. Oh well, first you make it then you fix it.
What are everyone's mounting ideas? I was thinking maybe just a camera tripod (it is 1.6kg), or a refractor dob mount like the one in Richard Berry's "Build your own telescope" (with round dob alt bearings on the sides). Ideas?
My 80mm is about the same weight with the rings and dovetail attached. It fits on a camera tripod but is decidedly shaky. Your second suggestion is probably best, a lot more solid.
I had a look earlier Chris, will have to dig up the Rainmaker pics.
Started on the 102 x 900, initial assembly done. Now for the tweaking. Will post progress in the other thread later.
. This will make thing much easier thanks for correcting me. I've never owned a refractor before so I'm a complete novice.
). Although with rivets you can just drill them out & re-rivet the offending part. I like the riveted look on my binoscope, it has a couple of kilograms of them.
Oh well, first you make it then you fix it.
