Quote:
Originally Posted by PRejto
Hello Eric,
Thanks for your further thoughts. Just playing the devil's advocate here, might my refractor be somewhat less sensitive to things such as non-orthogonal secondaries. etc when considering if a flat might help with the initial alignment of the rotator? I am of the opinion that I must do my very best to at least place the rotator as close to square as I possibly can. At this point the only "solutions" seem to be using a laser to aim at a mask over the objective, or "maybe" look at some flats to see if vignetting is even. Perhaps even a combination of both ideas would prove of some benefit. I don't know. (Josh suggested using a lathe with a dial indicator. Nice idea but I think impractical. How would I hold the OTA? And I don't have access to a lathe!).
I know that the earlier idea of putting a camera directly on the OTA is no longer under consideration, however, you did ask about numbers from my rotator test: The rotator was 20 feet (ca 6,000mm) from the wall and the beam moved a max of ~10 mm from center in a complete rotation. There are also 2 times where the displacement is quite rapid, almost like something is slipping in the rotator. I'd appreciate it if you could take a look at this video and give an opinion. Normal? Each square is 5x5mm.
https://drive.google.com/file/d/14PY...ew?usp=sharing
Thanks,
Peter |
Hi Peter.
In my opinion a flat frame isn't going to tell you anything about tilt, nor will tilt effect the look of a flat frame. Would you agree Eric?
With my idea of a lathe, i am asuming the mounting surface of the TEC is orthogonal to the optical axis... that leaves the rotator and its adapter to test... which you can put alone in the lathe, no ned for the scope aswell.
Was tht 10mm from center on side and 10mm on the other or 10mm total runout?
A dial indicator on the side of the rotating rotator will give you the runnout... i know i keep going on aboit it
Regards, Josh