LHIRES III focuser

[cynosure]

It might not strictly be the correct forum for this, as it is a bit of a project, but it is most likely to be of interest to people in this section. I have just had a bracket made with a motor, which I have added to my LHIRES III spectroscope. I find it makes focussing much easier, and this can now be done from the warmth of my study! It works well at the minute, my only worry is if the ealsticity of the drive belt changes and becomes too hard when it gets colder again in the winter. I will solve this if it becomes an issue. Anyway, for those that are interested, the link to my web page with pictures and description is:

http://www.cynosurechem.co.uk/Astronomy/Spectroscopy_HIRESIII_focus.html

Thanks,

jonathan

[Charles]

That's a great solution.  I think you are right to be concerned about the drive belt.  I don't know the answer, but I bet there is a good product out there.  these people (who I have not used) might have something.
http://www.modelfixings.co.uk/index2.htm

Good luck

[robin_astro]

That is an interesting mod. I have plans to fully automate my LHIRES eventually. (so far I have automated moving and switching the neon which as well as allowing me to stay in the warm has improved the repeatability of the calibration)  Have you checked if leaving the doublet unclamped affects the stability of calibration as the telescope moves round the sky? (Various flexure problems already limit the LHIRES wavelength precision)

Robin

[cynosure]

I have not checked this yet, it has been rather cloudy here of late, however, the drive belt is under a fair degree of tension and I would not expect much movement. I ran a series of checks under "bench" conditions over a week, moving it round, refocusing etc and it was surprisingly reproducible...unfortunately, I suspect that only time and field use will really show up any limitations.

jonathan