Bintel GSO BT252 f/4 Carbon Truss Newtonian
This Deep Sky imaging scope utilises Carbon fiber to eliminate weight, whilst the Serrurier truss design ensures there is no flexure in the scope and all the time looking very sexy.
The serrurier truss system, first designed by Mark Serrurier whilst working on the 200″ Hale telescope at Palomar mountain in 1935 has been used to stop flexure in telescopes. It works by supporting the primary and secondary mirrors with two sets of opposing trusses before and after the declination pivot point. The trusses are designed to have an equal amount of flexure, which allows the optics to stay on a common optical axis. By having one set of trusses working against the other set of trusses ,thereby keeping the optical elements parallel to each other. This keeps the scope in collimation regardless where the scope is pointed on the mount. The use of Carbon Fibre truss tubes eliminates the changes in focus due to thermal expansion.
The primary mirror is housed in an aluminium mirror cell. The mirror cell has six recessed collimation screws accessed from the rear of the scope. The push – pull collimation system holds the collimation more securely than knobs and springs. Three small computer type cooling fans arefitted to the rear cell to speed up the cooling of the primary mirror. Powered by 8 AA batteries (battery case only supplied) or can used external 12vDC power supply.
The secondary mirror is housed in a top cage with two aluminium rings, The top ring holds the secondary spider and secondary holder. Collimation is done from the front of the tube. An optional heater can be fitted around the secondary holder stalk. The bottom ring is the anchor point for the truss tubes. The hardware for holding the truss tubes is CNC machined in aluminium and uses Stainless hardware to holding all together.
The focuser is a 2″ Linear bearing Crayford design with a 1.25″ adapter both the 2″ and 1.25″ holders use brass compression rings for better centering and zero damage to expensive cameras and eyepieces. There are two course focus knobs and on one side there is a smaller Black fine focus knob. This has a reduction of 10:1 enabling fine focus. The focuser also has two thumbscrews on the underside for tension adjustment and locking focus. There is 51mm of travel of the drawtube and there is a scale on the drawtube with mm increments to enable zeroing focus easier with image train fitted.
Optional Coma Correctors are available in various brands and qualities, please email for details on each.
Losmandy D-Style Dovetail Bars are fitted top and bottom for mounting on mounts with D-style saddles.
|Optical design||Newtonian Reflector|