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16-1/8 x 0.70" f/6 Fused Silica (Quartz) Polished Blank Unfigured Sold!

Price - $350.00

Ad Number: 168899

Posted: 20 Apr 2019

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This is a 16-1/8 x 0.70" f/6 fused silica (quartz) mirror blank, fully polished out and fairly spherical. It will be going onto the generator soon to be remade as a very thin f/4 mirror so if it's interesting at all speak up soon.

But much of the work is already done if you want a longer focus mirror. Has some traces of AccuLap on the surface from the last go on the machine, and it has cerium residue on the bevels and sides.

At 23:1 it's a bit challenging to finish but doable if you have experience. Ronchi shows a basically spherical curve with a touch of long edge and some minor astigmatism. Nothing that some dedicated work with a large polisher wouldn't correct. One could take it directly to the paraboloid most likely if perfection wasn't your major concern as at f/6 it's pretty forgiving.

Quartz is an excellent substrate, with better thermal characteristics than borosilicat glass and slightly stiffer as well. Takes a superb polish.

Price is $350 firm, shipping included (domestic US) via UPS. Paypal only, no fees.

Thanks for looking!

NB: THIS IS NOT A FINISHED MIRROR. It requires parabolization to be usable in a Newtonian telescope.

General


  • Condition New
  • Location Salem, OR



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