Alstar AccuFocus Electronic Telescope Focuser - Auto Focus System for Astronomy & Stargazing - Perfect for Astrophotography & Night Sky Observation

Focusing a telescope by hand can cause the image to shake or even move completely out of the field of view, especially at high magnifications. But with the AccuFocus electronic focuser, those annoyances are a thing of the past. Please Follow these simple steps to install the AccuFocus. Phillips head screwdriver is required during installation (not included) Remove the focus knob from the right-hand side of the focuser. This is done by loosening the set screw that connects the knob to the focusing shaft (Figure 1). Use the supplied 1.5mm hex key to do this. After the set screw is loosened, simply pull the knob off of the focusing shaft.Remove the focuser’s locking thumb screw. This is the chrome, knurled thumb screw that locks the focuser drawtube in place (see Figure 1). Remove the four Phillips head screws from the focusing shaft cover plate. Use your thumb to maintain downward pressure on the cover plate so it does not fall off when the screws are removed (Figure 2). If the focuser drawtube rotates, that is OK. You can reposition the drawtube later, once the focuser bracket is connected.Use the supplied four Phillips head screws to connect the bracket to the focuser. The screws go through the bracket and the focusing shaft cover plate, and thread into the focuser. Do not firmly tighten the screws yet. If the focuser drawtube has rotated, rotate it back into position now. The flat area on the drawtube should make a good connection with the focusing shaft (see Figure 3).Now, firmly tighten the four Phillips head screws. Replace the focuser’s locking thumb screw. Do not tighten the thumb screw. Position the motor so the end of its shaft coupler goes over the exposed end of the focusing shaft.Insert the supplied thumb screws, with washers attached, through the slots in the motor’s bracket and thread them into the focuser bracket (Figure 4). You may need to rotate the motor to do this. Tighten the thumb screws firmly with your fingers; you can also use a flat head screwdriver to tighten the thumb screws.Engage the motor drive to the focusing shaft by tightening the set screw on the smaller end of the shaft coupler. Use the provided 2mm hex key to do this. For the most secure connection, make sure the coupler’s set screw seats onto the flat area of the focusing shaft. Use the set screw from the focus knob on the opposite end of the focusing shaft as a guide to determine rotationally where the flat on the shaft is (Figure 5). Use of the AccuFocus Using the AccuFocus to focus your telescope’s eyepiece is very straightforward and simple. Just push one of the buttons on the control box, and the focuser drawtube will begin moving. Push the other button to move the focuser drawtube in the opposite direction. To increase the speed of the motor, rotate the speed knob clockwise. To decrease the speed, rotate the knob counterclockwise.Generally, begin focusing with the AccuFocus at a higher speed to get close to focus. Then, slow down the speed as you approach the actual focus point to get the most precise focus. Keep in mind that best focus will be achieved by focusing on a bright star.Remember, if you wish to manually focus with the focus knob, be sure to first disengage the Accufocus. This is done by loosening the set screw(s) on the shaft coupler that connect it to the focusing shaft. Use the supplied 2mm hex key to loosen the set screw(s). Note: Do not turn the focus knob manually when the motor drive is engaged, or damage to the motor may result. Be sure to loosen the two set screws which connect the shaft coupler to the focusing shaft before attempting to manually focus with the focus knob. Installation steps Choose speeds from coarse to very fine with the adjustable speed control knob. DC motor installs easily and works with many Celestron, Skywatcher, Meade and Orion refractor and reflector telescopes. Troubleshooting If you are having problems with your AccuFocus, one of these tips may help. For rack-and-pinion focusers, make sure the four pinion gear cover screws are not too tight. They should be snug, but if too tight they will restrict the motion of the focuser’s rackand- pinion gears.The large thumb screw on the focuser’s body will lock the focuser drawtube in place once the telescope is properly focused. Before focusing with the AccuFocus, remember to first loosen this thumb screw. Do not loosen the thumb screw too much, as some tension helps keep the drawtube secure within the focuser.If you find the drawtube tension when focusing is either too tight (the AccuFocus struggles to turn the focusing shaft) or too loose (the image shifts when focusing or the drawtube does not move), you can adjust it by tightening or loosening the drawtube tensioning set screws on the focuser. These are the small set screws located near the focus lock thumb screw.If the motor shifts on the focuser bracket, tighten the thumb screws that connect the motor’s bracket to the focuser bracket more firmly. You can use a flat-head screwdriver to tighten the thumb screws, if necessary. For rack-and-pinion focusers, also make sure the two pinion gear cover screws that attach the focuser bracket are adequately tightened.If the shaft coupler is rotating with the motor, but the focus shaft is not turning, tighten the set screw(s) on the end of the coupler connected to the focusing shaft.If the shaft coupler is not rotating, but you can hear the motor running, try tightening the set screw on the coupler that connects it to the motor’s shaft. For Crayford focusers, this is the set screw on the knurled section of the coupler.If the motor begins to slow or no longer provides enough torque to smoothly rotate the focusing shaft, replace the 9V DC battery. Specifications： Fastest motor speed: Rotates focusing shaft approximately once every 7 seconds Slowest motor speed: Rotates focusing shaft approximately once every 28 seconds Item Weight 15oz/425g Focus Type Manual Focus Power Source Battery Powered (Not Include) Voltage 9 Volts (Not Include)