Telescope Making

11 April 2023

 See below for several current/active telescope projects.  For more information to join us email Jim Roe at

11 April 2023

Jim Roe's 3D Printed Telescope

This design came from the Internet and all the structural parts were printed on a Creality Ender 3 printer.  The 114 mm mirror and diagonal mirror were purchased on Amazon for under $30 and the aluminum rods were purchased locally (for about $32).  Miscellaneous #10 screws and nuts at a local hardware store.  Less than $100 total.

The gunsight finder was replaced with a 3D printed laser pointer mount for easier location of targets in the dark and the horizontal bearings were replaced to get a more stable mount.   It is a very good telescope for bright planets and the Moon.

A detailed description of its construction including STL files used with the 3D printer can be found here.

11 April 2023

Jim Roe's Schiefspiegler Project

The telescope design was published in a 1969 issue of Sky and Telescope magazine and I have wanted to make it ever since.  However, I was deterred by the mounting as I had no idea of how I could make such a mount with the hand tools that I've mostly had all my life.  When 3D printers became available I could see the chance to fabricate such specialized items as required so I got back into telescope making.

The special quality of this design is that it has no obstructions in the light path which  contributes extra diffraction spreading in the image which means lower contrast, especially on extended targets such as the Moon and planets.  On the other hand, it is limited in aperture to about 4.25 inches so those are the only practicable targets (but that's not too bad, it it?)

To see a detailed report, including the parts design for 3D printing, see here.


11 April 2023

Peter's 6 inch F/6 mirror

This is Peter rough grinding his 6 inch mirror blank  to a spherical surface of 72 inch radius with the help of our fixed post grinding machine.  The machine really excels at fine grinding which will be the next stage for Peter.

11 April 2023

Len's 4.25 inch mirror

Len started a 4.25 inch mirror while in High School but didn't finish it then.  But he came back to it and took it from a rough ground stage through fine grinding and polishing.  Figuring was an educational experience but this calculation of his surface error (compared to a perfect parabolic surface) shows the precision we are able to obtain.