Quote:
Originally Posted by Merlin66
Rom,
The original slit was two polished stainless steel blades, which could be "set" to any nominated gap width. The latest LhiresIII uses a chromed multi-slit plate (4 slits).
We found it VERY difficult to cut and polish s/s slit jaws to the required accuracy; then position them to maintain parallel, square surfaces to give the required consistant guide star image. In the end we gave up.
The Astronomical Spectroscopy group has recently got around this problem by designing, developing and getting OVIO (France) to make a Custom chromed reflective slit plate. This plate has 9 slits (100 to 20 micron) and three pinholes (100 to 20 micron). These are now available to members.
We are currently designing and prototyping an indexable holder and guide transfer mirror/ lens system (this will also incorporate a flip mirror/ lens system for reference lamps).
Hope this helps.
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Hi Ken,
My research ruled out tying to construct a set of jaws. Tedious and difficult without the right gear and the cost of a comercial adjustable slit is not that much compared to the sweat required to build one.
The technical drawings for the LHire III demonstrated the principle of the reflective plate to allow guiding but I was not convinced by the technique used. I have been contemplating an adjustable slit with an OAG for guiding but this is only a thought at this point in time.
The OVIO plate may be the answer but this is a new concept for me and part of the learning curve I still have to climb.
I assume the OVIO reflective slit will eventually use indexing based on the Hall-effect and I am very interested in this idea.
Rom