JMI Motofocus System

There are two basic types of MOTOFOCUS.  On the left is a Meade Rack-and-Pinion focuser with MOTOFOCUS attached.  On the right is a Push-On type MOTOFOCUS for a Meade LX style scope.


What is MOTOFOCUS?

MOTOFOCUS is a battery operated hand control with an electric focus motor that attaches to the shaft of a focuser knob (or the knob itself) for precise, vibration-free focusing without the need to touch the telescope.  It is great for visual and photographic use and features variable speed for coarse and fine adjustments.  Precise positioning is accomplished through electronic braking.  Mounting is easy and requires no drilling or tapping.  Add the Personal Computer Focus Control (PCFC) or Digital Focus Counter (DFC), for improved focusing accuracy and repeatability.

Q. What is the difference between a Focuser and MOTOFOCUS?
A. A focuser is the mechanical device that moves an eyepiece (or other equipment) in and out to bring an image into focus.  On the other hand, MOTOFOCUS units are designed to be attached to the shaft of a focuser knob (or the knob itself) to motorize the movement of the focuser.  It allows the focuser to be moved in or out without touching it.  Touching the focuser usually causes unwanted movement in the whole telescope.
   
Q. Are your MOTOFOCUS motors AC or DC powered?
A. All JMI MOTOFOCUS motors are DC powered.  The unit designed for the Meade LX200 plugs into the telescope control panel and is controlled by the LX200 hand unit.  All other MOTOFOCUS units are designed to operate with a JMI hand unit.  These hand units include variable speed control and electronic braking and are powered by a single 9-volt battery (or two 1.5-volt AA batteries in a few older hand units).
   
Q. How much focusing control does a MOTOFOCUS give?
A. With practice, you can move the focuser drawtube in increments much smaller than the thickness of the average business card.
   
Q. How is the MOTOFOCUS unit attached to the telescope?
A. All MOTOFOCUS units designed for rack-and-pinion focusers attach the same way.  One of the focuser knobs is removed and the MOTOFOCUS coupler is pushed over the exposed drive shaft.  The motor bracket is then secured to the focuser.   The units made for SCTs are friction-driven push-on motors that go on and off the focus knob in seconds for easy storage.
   
Q. Can I get some kind of visible readout of drawtube position?
A. Yes!  Simply order the Digital Focus Counter (DFC) upgrade at the same time you order your MOTOFOCUS or you can purchase the Personal Computer Focus Control (PCFC) system for displaying and controlling the position on a computer screen.  Since the upgrades are integrated during manufacturing, they cannot be added later.  DRO and DFC upgrades are not available for ETX and NexStar telescopes.
   
Q. Are there any telescopes for which you do not make a MOTOFOCUS?
A. Helical and slide tube type focusers are not suitable for MOTOFOCUS.  We also do not make a MOTOFOCUS unit for any focuser that is physically unable to support the system.
   
Q. Do you have MOTOFOCUS for telescopes not listed here?
A. We have MOTOFOCUS units for many older telescopes.  Even if your equipment is not listed, we may still have parts in inventory.  However, the cost will be much higher than for those shown in our online store.