The Baader 2-inch Diamond Steeltrack for Refractors (BDS-RT) is a heavy duty focuser that is backlash free like a Crayford design, but capable of holding a greater weight due to the surface against which the roller presses. To make the most of the focuser you will need: the correct telescope adapter (to allow the focuser to attach to your telescope tube after you have removed the stock focuser) the correct eyepiece or camera-side adapter (to allow you to attach whatever equipment will go on). The focuser is supplied with a 2″ compression ring. The focuser has 80 mm focus travel Minimum height (as supplied – incl. 2″ compression ring): 78 mm Minimum height (with optional S58 to M68 / M68i / M48 / T-2 direct-adapter): 65 mm Minimum height (with optional S58 ClickLock clamp): 89 mm Focuser weight (as supplied – incl. 2″ compression ring): 1.160 g (40.9 oz) Adapters available or under development to fit a wide variety of refractor telescopes Drive system True diamonds form a micro-geared high precision drive system never accomplished before In comparison to conventional crayford or rack & pinion drives, this micro-geared movement has zero backlash, zero cogging, and zero flexure Diamond Steeltrack 2″ focusers lift a payload of 6kg (13 lbs) straight up, without slipping, without excessive bearing preload (bearing preload can be increased further if necessary) Bearing system utilizes unbreakable Instrument Grade Roller-Bearings instead of simpler Ball Bearings – handles higher loads with greater rigidity and accuracy. No Teflon-pads anywhere 1:10 Stainless Steel fine-focus mechanism, ready for attachment of the optional Diamond Steeldrive temperature-compensating motor drive system Detachable drive block assembly is reversible for right hand or left hand fine-focus operation and for attaching the Diamond Steeldrive motor block Shortest possible mechanical design achieves optimum balance between focuser height (backfocus) and rigidity requirements Zero shift locking knob to precisely stop any movement without affecting optical axis adjustment Clamping system S58 Dovetail ring-clamp built into focusing tube for accepting optional T-2 / M48 / M68 and other S58 direct-thread adapters to enable direct thread connection of accessories and cameras without 2″ clamp 2″ eyepiece clamp with hardened bronze clamp ring (length of clamp: 12.5mm / ½”) included as standard Optionally available 2″ Baader Clicklock-clamp w. integrated S58 dovetail (added length: 16mm / 5/8″) Two auxiliary threads (M60x1 and M55x0,75) cut into the RT & NT focusing-tube for attachment of dedicated field flatteners or focal reducers/correctors Focusing Drawtube: Each bearing individually adjustable for precise alignment of mechanical vs. optical axis Ultra-hard subzero coated bearing races – precision milled and much harder than anodizing or stainless steel Oversized 55mm inner clear diameter, to prevent vignetting, with anti-reflection knife-edge baffles
