The Shoestring Astronomy Store

Focus Motor Control Products


Shoestring Astronomy has always been an "evening and weekend" enterprise when I was employed full-time. Now that I am retired, we do like to travel frequently. I will do my best to fill orders and respond to emails in a timely manner, but please realize that there may be times when I cannot respond as quickly as I would like to.

Thanks for your patience, and your patronage. Doug Anderson

DC Focus Motor Control
The FCUSB is a product that allows you to control a DC focus motor (or any DC motor for that matter) by way of a USB port and software on your computer. If you are already using a computer in your observatory for other reasons, this provides a way for you to focus your telescope without fumbling around in the dark for the focuser handcontroller. It works best with 5V focus motors such as the newer style JMI Motofocus, but can also work with 9V or 12V motors. Motors requiring up to 100mA of current will work with the FCUSB. To date, the FCUSB has been tested with the JMI Motofocus, Moonlite DC motorized focusers, Orion AccuFocus, Meade 1209, Televue Focusmate Driver, and WalterLee heliFocus. The FCUSB also eliminates the need for a battery to run your focuser, since the motor is now powered directly from the USB port of your computer. Using the free FocusPal software, you can control the speed and direction of your motor with just mouse clicks! For further information, please read through the FCUSB User Manual Third-party software that supports the ASCOM Focuser standard will also work with the FCUSB using the FCUSB ASCOM driver. DC focus motors don't provide absolute positioning repeatability like a stepper motor does, but we have tried the FCUSB with third-party autofocusing software and obtained decent results. However, there is no guarantee that this will work for all systems.

Why the FCUSB2?
Many astrophotographers need to use two focusers, one for their imaging scope, and one for their guide scope. One of the inherent problems with most USB devices is that when two of them are used, they will appear identical to the computer and there is no easy way to tell one from the other. Thus, we created the FCUSB2. It is identical to the FCUSB in all respects except for its USB identifier. So, if you wish to run two focusers, you will need a FCUSB and a FCUSB2. The FCUSB will work with only FocusPal, the FCUSB ASCOM driver, or the FCUSB FocusAPI driver. The FCUSB2 will work with only FocusPal2, the FCUSB2 ASCOM driver, or the FCUSB2 FocusAPI driver.

Moonlite Focuser Variations
Moonlite Focusers made a change to their pinout sometime around 2013. Older focusers used an RJ22 modular connector and are compatible with our FCCBL-01 adapter cable. Their newer focusers use the tip and ring of a stereo audio connector and are compatible with our FCCBL-02 adapter cable. If you are in doubt as to which one you have, please consult with Moonlite prior to placing your order here.

FocusPal by Shoestring Astronomy
You have many choices on software to use with your FCUSB. You can use any third-party software that supports the ASCOM Focuser standard, or you can use FocusPal from Shoestring Astronomy. It is a stand-alone program that allows you to control the speed of your focus motor, and to run the motor in and out. It is free and can be downloaded using the link found below. Even if you plan on using third-party software, you should download and install FocusPal to verify that your FCUSB, computer, and focus motor are all working properly together. If your system works fine with FocusPal, but not with your third-party software, then the problem most likely lies with the third-party software and you should contact them for technical support. If your system does not work with FocusPal, then you should contact us for technical support.

Shoestring Focus by Stark Labs
If you own a Mac computer, Craig Stark has written an application very similar to FocusPal that allows you to control your FCUSB or FCUSB2. It is available for free from Thank you, Craig.

INDI Drivers
For LINUX, Raspberry PI, and MAC OSX Developers, INDI drivers for the FCUSB and FCUSB2 are available at and

PayPal Buy
fcusb.jpg (70 kbytes)

USB Focus Motor Controller


USB Focus Motor Controller User Manual

Click here to view/download. (Requires Adobe Acrobat Reader)

  Absolutely Free  

Install FocusPal

Click here to install the free software you can use with your FCUSB.

  Absolutely Free  

Install FCUSB ASCOM Driver

Click here to install our free FCUSB ASCOM driver.

  Absolutely Free  

Install FCUSB FocusAPI Driver for use with CCDSoft

Click here to install our free FCUSB FocusAPI driver.

  Absolutely Free  
fcusb.jpg (70 kbytes)

USB Focus Motor Controller for Second Motor


Install FocusPal2

Click here to install the free software you can use with your FCUSB2.

  Absolutely Free  

Install FCUSB2 ASCOM Driver

Click here to install our free FCUSB2 ASCOM driver.

  Absolutely Free  

Install FCUSB2 FocusAPI Driver for use with CCDSoft

Click here to install our free FCUSB2 FocusAPI driver.

  Absolutely Free  
Adapter cable (8 feet) for motors with RJ22 connector (older Moonlite, Orion Accufocus, Skywatcher SWELFOCUS, and Televue Focusmaster Driver, wired to tip and sleeve)
Adapter cable (6 feet) for newer Moonlite motors with stereo connector (wired to tip and ring)
6 foot male-female extension cable
10 foot male-female extension cable
6 foot male-male extension cable
10 foot male-male extension cable