Explore Scientific PMC-eight Stepper Smoother Box

Astrophotography using an equatorial mount telescope requires precise motion control in order to produce sharp images. This is particularly true for the RA axis motion. Explore Scientific (and other manufacturers) mounts use stepper motors to control the RA and DEC axis motion. The step motion is improved when the stepper controller board has an increased voltage drop to the RA stepper at all times. This is accomplished by adding opposing diodes on each of the steppers 4 wires in order to create a voltage drop. The smoother PC board (purchased online) has the diodes mounted in this manner and requires no soldering. The smoother boards are sold with 4 wire cables that are used in this design to connect to a male and female serial DB9 connector (purchased online). The three - 3D printed parts house the smoother card and DB9 connectors and provide a clean way to attach this circuit to the RA axis of the mount. The serial RA cable from the stepper driver box plugs into the female port on this assembly. The male port on the other end of this assembly plugs into the equatorial mount RA port.

The photographic improvement for planetary astrophotography is still being debated in astronomy forums. I encourage you to try this add-on circuit and report back on the results.