PLate OPtimizer: Difference between revisions

Revision as of 03:13, 21 May 2009

Revision as of 10:11, 21 May 2009

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{{notability}}

{{ otheruses4|the CAD program, PLOP|the computer language conference group, PLoP|Pattern Languages of Programs}}

{{Notability|date=May 2009}}

'''PLate OPtimizer''', or '''PLOP''' is a [[CAD]] program developed by [[telescope]] maker David Lewis, first described in 1999,<Refref>{{Citation| last = Lewis| first = David| author-link = | title = | journal = Sky & Telescope| volume = | issue = June| pages = 132-135| date = | year = 1999| url = | doi = | id = }}</Refref> and used to simplify calculations needed in the design of [[Mirror#Instruments|mirror]] support cells for [[telescope]]s.<Refref>{{cite web| last = Holm| first = Mark| authorlink = | coauthors = | title = Mirror Cells for Amateur Telescope Makers| work = | publisher = | date = | url = http://www.atmsite.org/contrib/Holm/Plop_optimized_cells/index.html| format = | doi = | accessdate = May 3, 2009 }}

</Refref> It was based on Toshimi Taki's 1993 program PLATE<ref>http://www.asahi-net.or.jp/~zs3t-tk/cell/cell.htm Taki's brief intro to cell design</Refref>, however provides a simplified user interface, thus giving it wide acceptance among makers of large [[Dobsonian telescope]]s, with good support of mirrors as thin as two inches for a diameter of thirty inches.<ref>{{cite web| last = Anderson-Lee

| first = Jeff| authorlink =| coauthors = | title = Best of 18 and Over - A collection of plop cell designs

| work = | publisher = | date = | url = http://www.cs.berkeley.edu/~jonah/18plus/| format =| doi = | accessdate = May 3, 2009}}</ref>

PLOP produces less mirror [[Yield (engineering)|stress]] than equal area rule calculation: it uses [[Finite element analysis]] and can be set to ignore [[Deformation (engineering)|deformation]] which merely results in refocus of the mirror's [[parabola]].<ref>[http://www.atmsite.org/contrib/Holm/Plop_optimized_cells/cellfaq.html#old Atmsite PLOP FAQ]</ref> It is useful to calculate floating support points for mirror [[Optical axis|axial]] (rear) support however additional tools are needed to calculate potential error from mirror lateral (edge) [[Lateral support|support]].<Refref>http://www.cruxis.com/scope/mirroredgecalculator.htm ''Cruxis'' site mirror edge support calculator tool</Refref> Additionally, PLOP calculations do not overcome error introduced by gluing the mirror to its cell, excessive tightening of edge supports nor impingement of the cell structure onto the mirror as result of differential cooling shrinkage. PLOP is not sufficient for the significantly more complex calculations arising from the support of large [[honeycomb mirror]]s nor those using [[active optics]] systems.<Refref>http://medusa.as.arizona.edu/lbto/tech/ua9502.htm Mirror Support System for Large Honeycomb Mirrors</Refref>

==See also==

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==External Resources==

* [http://www.cs.berkeley.edu/~jonah/18plus/p18.html A Study of 18-point Mirror Cell Optimization Using Varying Forces] Jeff Anderson-Lee, January 2003

* [http://www.davidlewistoronto.com/plop/ David Lewis authorlink]