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Weight of SCT primary mirrors??
Anyone know the weight of say the 8", 10" 12" etc Meade SCT primary mirrors?
I've got a 12" which has some, not a lot of mirror flop, but just enough to move a star of my 20 micron slit in the spectro.
The usual solution ( see MAPUG for details) is to put a locking screw into the the rear cell. I don't think this is great. BTW the latest GPS versions have a locking collar which "grabs" the central baffle to reduce clearance and hence flop, but again, I don't think it's great.....
What we need is "Harry's Mirror Mat", can be fitted to any Meade ( don't know about Celestron yet) and will 100% support the mirror, anywhere in its travel up and down the baffle WITHOUT flop!!!!!!!!
I'm putting together a pneumatic tube/ring about 2" wide which will support the back of the mirror near the edge. Needs about 1.5psi ( a hand air camera release will do) to support what I think is about 30Lbs for a 12" mirror.
The air supply tube, about 4mm diameter can be routed throught the locking screw hole in the rear cell, so no additional machining required.
To prevent over pressure a poppet valve will be set to limit the pressure ( to suit the mirror weight) so that it's safe.
" Harry's Mirror Mat", coming to a SCT near you.
To finalise my design, it would be good to know the various mirror weight to set the pressure range.
Any comments, development $$$, donations????
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