TS-Optics 2" MONORAIL focuser with 96 mm flange connection
The TS monorail focuser for many Skywatcher, Celestron and Orion refractors is a further development of the proven Crayford focuser. Our goal was to offer a focuser for the highest loads, such as heavy CCD cameras, with very high precision at the same time. This is exactly what the Monorail extensions have achieved.
The MonorailR96 has a 96mm connection flange with three M4 internal threads and 360° rotation on the telescope side. This allows connection to Skywatcher and Orion ED refractors from an 80mm aperture, as well as Skywatcher, Celestron and Orion achromatic refractors from a 102mm aperture.
Summary of the advantages of the TS Monorail focuser:
♦ Higher resilience than normal Crayford focusers: instead of small ball bearings, a solid stainless steel rail is used, which is fixed on the side.
♦ More precise guidance of the air chamber and no more tipping when clamping
♦ smooth operation and finer adjustment even with loads up to 4 kg
♦ 1:10 micro-speed reduction for precise focus
♦ Motor focus can be tailored
Attaching a seeker shoe
The headless screws marked in the third picture above can be removed and one or two finder's shoes can be attached with one M4 screw each. Make sure the screw used does not go deeper into the focuser than the grub screw! Otherwise, the drawer may be damaged.
How the MONORAIL focuser works and the advantage over Crayford focusers:
Instead of small ball bearings, as is the case with Crayford focusers, a solid stainless steel rail takes care of storage as well as lateral fixing.
The downside of ball-bearing Crayford focusers: The small ball bearings in the Crayford focuser are loaded when clamped. Also, since the clamping screw is not located exactly between the ball bearings, a pair of ball bearings will be more heavily loaded. The result is tilted, fuzzy stars in one corner.
The advantage of the MONORAIL principle: the function of the ball bearing is taken over by the stainless steel rail, which is permanently connected to the extension tube. Nothing can go wrong there anymore. Only the side guide is still taken over by ball bearings. However, these bearings only fix the lateral position and no longer have to absorb any load.
The extension tube is fixed with a clamping screw, which is located exactly in the middle at the top. As a result, the entire structure is uniformly loaded. Definitely no more twisting, the extension tube remains 100% in the prescribed position.
With the lower center screw you only adjust the friction (resistance to friction) - see the image on the left.
||Flange, 96 mm diameter with three radial M4 thread bores
|Eyepiece side connection:
||2" receptacle with compression ring and reduction adapter to 1.25"
|Minimum height from telescope flange to 2" receptacle:
|Draw tube travel:
||mmm and inch
||Stainless steel rail - Monorail principle
||860 g incl. 1.25" reduction adapter