Wednesday, March 27, 2013







Here's an example of a 9-point flotation mirror cell for a 13.1" thin mirror (5/8" thick). The cell components are a combination of aluminum plate and a Baltic birch substrate. The mirror will affix to the cell with silicone. The placement of the 9-points (three triangles) were computed by, and optimized, with Plop

Sunday, March 24, 2013

Kevin's 12.5" Telescope with ETT option.

















Here's Kevin's 12.5" telescope. The ETT (Easy Transport Telescope) option is complete and installed. Another benefit of this design is that intermediate ring lends a bit of extra "rigidity" to the OTA assembly.

Saturday, March 23, 2013


12.5" F4.78 for Kevin A. in Billerica MA.
 A 12.5" telescope for Kevin A. in Billerica MA.  The mirror a very nice F4.78 with new coating. Kevin asked that the telescope be built and shipped without a "finish" so he could apply a custom color of his choice.

Yet to be completed is the ETT (Easy Transport Telescope) option. The ETT option will cut the struts in half with an intermediate ring to reintroduce the rigidity of the assembly.

Here is Kevin's "finished" telescope (4/29/2013).









Filer slide pulled in the full "out" position.












A unique feature of the telescope is a "filter slide". just below the focuser. It allows the use of 3 filters -- or none -- as desired by the observer.. In this photo, the filter slide is pulled all the way "out" along the optical axis.







Mirror slide, Moonlite focuser and Destiny spider.










Here, the filter slide is "down" into the OTA and in the "no filter" position.









Detail of the mirror cell with counterweight mount -- if needed.









As part of the build, Kevin provided me with a University Optics mirror cell. You can see, in the center, an additional mounting "bolt" for counterweights if needed.













Detail of the mirror-box and rocker-box. The mirror cover is to the left of the photo.

Friday, March 8, 2013

12.5" Profile. Note the "strings".





 I'm just about complete with Richard's 12.5" telescope with a Zambuto mirror. This is an F5.74, so it's a longer focal length. Notice the "strings" that add rigidity to the scope. The secondary and spider are Protostar and the focuser is a Feather touch. Very nice. A nifty feature are two corner eyepiece holders on the inside of the rocker box. These also add a bit of rigidity as well.

Rear of the 12.5" scope with fan.

Rocker Box with Eyepiece "corner" trays.

Protostar Secondary and Spider.
Feathertouch Focuser.

Tuesday, March 5, 2013

A 12.5" F5.74 for Richard in Palm Coast Florida. His telescope sports a very nice Zambuto primary mirror, Protostar 4-vane spider and Feathertouch focuser. The mirror cell is a 9-point flotation cell made by an unknown vendor but modified to fit in my telescope design.

The telescope is still under construction. Yet to be completed is the string option, primary mirror fan and a couple of eyepiece holders in the inside corners of the rocker box. So far, though, the scope is look very good. The motions are great and the images are really good with that Zambuto mirror.