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Alstar AccuFocus Electronic Telescope Focuser

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$68.99

$ 33 .99 $33.99

In Stock

About this item

  • The electronic telescope focuser kit contains a variety of parts including two different types of focuser brackets; hardware and coil cables
  • There are three installation methods for this electronic telescope focuser that is simple to install and makes achieving sharp focus easy
  • The control box requires a standard 9V battery to operate; The 9V battery goes into the battery compartment in the rear of the control box; which can choose speeds from coarse to very fine with the adjustable speed control knob on the box
  • Choose speeds from coarse to very fine with the adjustable speed control knob for precise focus adjustments
  • Accufocus electronic focuser cannot be used on Maka; DOB type telescopes and telescopes with APO two speed focusing; but only on telescopes with single speed focusing such as some brands of refractors and reflectors in the 60 to 127 mm range



Product Description

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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)

  1. 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.
  2. 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.
  3. 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).
  4. 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.
  5. 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.
  6. 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).
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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

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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.

  1. 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.
  2. 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.
  3. 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.
  4. 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.
  5. 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.
  6. 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.
  7. 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)

Mike
Reviewed in Canada on January 31, 2025
Bought it 2 years ago for future project. Right now new open box, the variable speed dont work! Brain new, never use before... Motor turn clockwise and conterclockwise but variable speed dont change anything to the speed. Not Happy :-(
Customer
Reviewed in the United States on May 31, 2024
Very good product, work very well on my Lunt 60mm solar telescope ,
ANIBAL SANTOS HERNANDEZ
Reviewed in Mexico on May 1, 2024
La instalacion fue facil, el resultado muy bueno
carla mchenry
Reviewed in the United States on March 28, 2024
I have a new SVBony SV503 80mm ED telescope and wanted an electronic focus motor so I tried this inexpensive focus motor. Not only did the mount bracket not fit (too short and a bad angle) but the motor has such low torque that even with the focus mechanism on the scope set as loose as possible it would not budge the focus knob shaft. Returning in the morning. If you have a SVBONY SV-503, this is not the control unit for you. YMMV but it was totally wrong for my OEM setup.
Melanie
Reviewed in the United States on December 9, 2024
Easy installation, it worked wonderfully but in just two months the buttons hang open and you must unplug it to stop it.
e100
Reviewed in the United States on April 12, 2024
The media could not be loaded.
Will
Reviewed in the United States on March 14, 2023
Purchased this for my Carson RP-400 refractor. Neither of the two brackets worked. One of them might work if I modify it by cutting the area that is supposed to attach to the focuser in half. Then, I would have to drill two new screw holes. Too much work and I don’t even know if the motor is going to be worth it. Additionally, the instructions images are impossible to make out.
Dave
Reviewed in the United States on November 9, 2022
The first one I ordered was damaged in transit or something according to Amazon so I had to order again. Still haven't received the refund for that one. I had to order another and it showed up quickly. However, it's cheap. The motor is weak. The brackets included were worthless and I ended up having to fabricate one of my own. Even with this I'm not sure this thing will last me. I also had to solder one of the battery leads to the circuit board inside the hand controller because it came loose the second I put a 9v battery in there. The battery compartment door also doesn't stay in place. Cheap. Definitely not worth the 75 bucks I spent on it. I will test the whole setup tonight or tmw after the weather clears. That will be the real test and I imagine that as much draw as that motor puts on that battery, that I will have to put a new battery in every night. We shall see. I may end up returning this. Don't waste your money or your time on it.
christopher watson
Reviewed in the United Kingdom on October 15, 2022
After installing the box didn't work in one direction. The working direction failed after 5 seconds of use with a burning smell. I've since checked the motor and it works the focuser perfectly in both directions with 9v applied to the motor. I don't see any way to contact the seller to get a replacement box. The only option is to refund which seems silly when I only need a replacement box. Otherwise the quality is good and fits perfectly.
Well Read in Iowa
Reviewed in the United States on June 16, 2021
Great product, was easy to install and instructions are easy to follow. Works well with my Newtonian telescope, worth the money.
KyFarmBoy
Reviewed in the United States on April 16, 2021
I had assumed that this was a generic device that should work with most telescopes. The first one I received would only adjust in one direction. A replacement was sent almost immediately by Amazon. It required modifications to the mounting bracket in order to fit my rack and pinion adjustment on my Orion telescope. I had the tools to do the mods but not everyone will. The bracket I used was not made for a flat surface so I flattened it using a bench vise. I then had to cut off about half of the bracket (see the photo) and enlarge the two holes slightly for the mounting screws. The coupler between the motor and the rack and pinion was too large for the adjustor shaft. I enlarged the shaft for the adjuster using shrink sleeves used for electrical connections. So far it works very well. Price wise it was very reasonable.
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