NC16 Mechanical design

The tube is made of carbon fiber with less than 4 Kg weight.

The main mirror is supported with 18 points optimized using the PLOP software.

Bafling is precissely calculated to do not introduce vigneting.

The focuser model is the OK3-Z from ASA and could be exchanged between the newtonian focus to the cassegrain focus.

Back focus for the cassegrain configuration is 180 mm.

Both secondary mirrors have 100 TPI screews for precise collimantion, locking screews, and high tension spring.

Three low speed fan suck hot air from the tube to outside (full tube volume every 20 seconds).

THE CELL

The cell is composed by an outer tube connection that connects the bottom plate to the tube. This bottom plate contains three fans removing the hot air from the tube, a focuser adaptor and tilting screws for the primary. The primary mirror rests on 18 support mechanism composed by three groups with two triangular plates containing three contacting points. The mirror is centred mechanically by a central cilinder and retained with inner and outer rings. A baffle connects to this support. The lens correction group is adjusted and screewed to the bottom plate. This guarantees perpendicularity with the CCD camera and focuser and is not affected by tilting the primary.

Note that the central cilinder supports the mirror from the walls of the central hole, but the diameter close to the front surface is smaller. This is done on this way to avoid scratching the front surface when introducing lateral forces on this part.

THE TUBE

The tube will be made of carbon fiber, with 1.5 mm inner unidirectional carbon fibers, 8 mm central nomex, and 1.5 mm additional outter unidirectional carbon fibers with a final layer of 2K twill and clear coat. Length of the tube is 1252 mm and wall thickness is 11 mm. Total weight is only 4 Kg. Inner diameter is 460 mm. The tube contains two end rings made of alluminum with 485 outter diameter. Support rings are also made with a carbon fiber structure.

NEWTONIAN CONFIGURATION

For the newtonian configuration, the diagonal supporting the spider is screwed to the outer parts of the tube with the use of suporting tube plates. The spider has three 100 TPI screws for precise collimation and is fully assembled on high tension spring and locking screws. The light cone is directed to the outer part of the tube where a OK3-Z focuser from ASA is located.

The spider vanes are made of 0.5 mm stainless steel in double vane configuration.

Note the inner ring located below the spider. This ring is permanently fixed and used for the assembly of the cassegrain secondary.

CASSEGRAIN CONFIGURATION

For the cassegrain configuration the newtonian spider is removed. The secondary is permanently assembled on a separate ring and a similar support for the newtonian diagonal for precise collimation. The suporting ring enters through the top and is screwed to the inner ring. Four pin reference are used for precise centering.

Final image of the full telescope assebled on top of the german mount.

THE CELL The cell is composed by an outer tube connection that connects the bottom plate to the tube. This bottom plate contains three fans removing the hot air from the tube, a focuser adaptor and tilting screws for the primary. The primary mirror rests on 18 support mechanism composed by three groups with two triangular plates containing three contacting points. The mirror is centred mechanically by a central cilinder and retained with inner and outer rings. A baffle connects to this support. The lens correction group is adjusted and screewed to the bottom plate. This guarantees perpendicularity with the CCD camera and focuser and is not affected by tilting the primary. Note that the central cilinder supports the mirror from the walls of the central hole, but the diameter close to the front surface is smaller. This is done on this way to avoid scratching the front surface when introducing lateral forces on this part.
THE TUBE The tube will be made of carbon fiber, with 1.5 mm inner unidirectional carbon fibers, 8 mm central nomex, and 1.5 mm additional outter unidirectional carbon fibers with a final layer of 2K twill and clear coat. Length of the tube is 1252 mm and wall thickness is 11 mm. Total weight is only 4 Kg. Inner diameter is 460 mm. The tube contains two end rings made of alluminum with 485 outter diameter. Support rings are also made with a carbon fiber structure.
NEWTONIAN CONFIGURATION For the newtonian configuration, the diagonal supporting the spider is screwed to the outer parts of the tube with the use of suporting tube plates. The spider has three 100 TPI screws for precise collimation and is fully assembled on high tension spring and locking screws. The light cone is directed to the outer part of the tube where a OK3-Z focuser from ASA is located. The spider vanes are made of 0.5 mm stainless steel in double vane configuration. Note the inner ring located below the spider. This ring is permanently fixed and used for the assembly of the cassegrain secondary.
CASSEGRAIN CONFIGURATION For the cassegrain configuration the newtonian spider is removed. The secondary is permanently assembled on a separate ring and a similar support for the newtonian diagonal for precise collimation. The suporting ring enters through the top and is screwed to the inner ring. Four pin reference are used for precise centering.
Final image of the full telescope assebled on top of the german mount.