They arrived, the sender is from Hong Kong, and that explains why the shipping is cheaper than quoted (which is to US).
They're very small, less than 1 inch long (exluding the output shaft), the gears are metal, and the gear box are made of brass.
I shall test them out tonight when I have time. I believe these are perfect candidates to do motorized focusing work, given they're small and powerful, and with suitable RPM at 6V.
Phrase one of the project will be to make a manual guiding box, here's the list of things to do:
1. shaft coupler to connect the 3mm shaft of the motor, to the 6mm shaft of the TG-SP II
2. M1.5 screws to mount the motors to a board
3. a plastic board: to drill holes there to mount the motors, the power supply and the circuits boards
4. 3-way switches, to make the dual motors controller box
Maybe the plugs and cable from my old indoor wireless phone can serve as the connection from the controller box to the motor units, since it has four wires inside. :-)
This piece of hardware seems to be very useful for autoguiding:-
It uses a USB port (HID type), can control two DC motors for bi-directional movement or four DC motors for single direction. External power supply can be used to drive the motors, or I guess it's also easy to put the power from the USB port to power the motors. PWM is used to control the motor speed as well.
Sounds too much like the shoestring controller... it's tempting for me to check mine.
The price is inexpensive at 28 british pound. It's cheaper than to buy a ST-4 USB adapter, and it also makes the wiring simpler. All I will need to do is to write a ASCOM driver.