Feather Touch 3.5" Dia Dual Speed Focuser Body, 4.5" DTT, with Brake
- Focuser is fully rotatable relative to telescope position
- Locking ring for rotation feature allows on the fly adjustment and locking
- Heavy duty 10:1 reduction unit
- Course focus on both sides of pinion housing
- Interchangeable end caps
- Laser scibed scale on both sides of the draw tube (115mm with 1mm resolution)
- Precision manufactured from the best materials available and built for long life and trouble free operation. All alumimum parts are anodized and all other non alumimum parts are corrosion resistant stainless steel. No short cuts and no compromise in the design!
- Machined (sharp edge type) internal light baffles for best low reflectivity properties
About our Internal Brake System...
Because the focuser is so smooth in operation and moves so freely, it can only hold a limited amount of weight (generally about 1 lb.) without drifting out of focus when the focuser drawtube is not horizontal and has a vertical component. The focuser therefore contains an adjustable tension internal brake system to allow astrophotography and visual use with heavy eyepieces without the possibility of the focus shift.
The brake consists of a lever arrangement internal to the pinion block. Adjusting the thumbscrew on the pinion block causes the lever to press a friction pad onto the pinion. This increases the torque needed to turn the focus knobs. If the thumbscrew is turned all the way in (only 1 to 1½ turns), the pinion shaft and the drawtube are locked in position for long exposure astrophotography.
Visually, partial tightening of the internal brake offers a virtually infinite range of braking force to accommodate various eyepiece weights. Moderate finger-pressure tightening of the drawtube tension screw allows the lifting capacity to be adjusted up to a nominal maximum of five pounds, although greater payloads are possible by further tightening the tension screw.
|Name||Starlight Instruments - Feather Touch 3.5" Diameter Dual Speed Focuser Body, 4.5 " DTT, with Brake|