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First-time installation and quick start

WD-20EPFirmware: WD-20EP mount build; AHC 1.1.0 interface reference

Follow this sequence for a first session in GEM mode. It provides the essential checks and links to detailed instructions. Plan the first test while you can see the entire setup clearly; finish polar alignment under the sky before imaging.

In this chapter

2.1 Before you begin​

Prepare a compatible tripod or pier, correct mounting fasteners, telescope and dovetail, the supplied 24 V / 200 W adapter, the AHC cable and any required counterweights. For saddle-powered equipment, list every device's required voltage and current and choose the correct PD or supplied 12 V PD-to-DC cable. For computer control, also prepare a data-capable USB cable and the appropriate software.

  1. Check the model is WD-20EP and inspect the mount, cable insulation and connectors for transport damage.
  2. Select firm, level ground with clear space around the tripod and the complete telescope travel.
  3. Assess payload mass, RA torque and tripod stability using 3.5.
  4. Identify the power switch, mechanical locks and AHC STOP button.
WARNING · Falling equipment

Hold the mount firmly during installation. Do not leave it resting unsecured on a tripod or support plate, and keep hands clear of moving joints and clamp edges. If you place the mount on a table or another flat surface for inspection, check stability at the selected latitude angle and keep it supported. It can stand initially and still tip when either axis rotates. Do not command powered movement until it is fastened to a compatible tripod, pier or secured adapter.

2.2 Install the mount and telescope​

WARNING · Telescope attachment

A partly engaged dovetail can fall when the mount changes orientation. Verify engagement and clamping from both sides. Never loosen the saddle while leaving the telescope unsupported.

  1. Extend and secure the tripod, or check the pier and its adapter. Level the support.
  2. Attach the mount with the compatible center or three-point mounting arrangement. The mounting screws must enter the base by no more than 10 mm; select their length for the adapter thickness. Hold the mount until all required fasteners are secured. Check for rocking or looseness.
  3. Before adding the telescope, choose the coarse latitude position appropriate for your observing latitude. See 3.6.
  4. Install any required counterweight shaft and weights using their retaining devices. Combined counterweight mass must not exceed 10 kg to protect the M12 attachment thread.
  5. Support the telescope, seat its Vixen or Losmandy dovetail fully in the matching saddle channel, and tighten both clamp knobs. Check attachment before releasing your support.

Detailed instructions: Chapter 03, including fixed-pier, folding-pier and tripod examples.

2.3 Check and adjust the mechanical setup​

Immediately after telescope installation:

  1. Check the complete payload, including the camera, guider, focuser and cables.
  2. Check counterweight retention and overall tripod stability.
  3. Fine-adjust latitude to approximately your local latitude and point the polar axis toward the appropriate celestial pole. Generally leave the latitude-lock handles locked for routine fine corrections; release them for a correction greater than 2° to avoid adjustment-screw wear. See latitude fine adjustment. Fine-adjust azimuth after loosening only the relevant azimuth locks enough to permit adjustment.
  4. Secure any mechanical locks you released. Route cables with enough slack for both axes, with no loops near pinch points. Keep saddle power/data leads away from the dovetail clamps and ensure that a meridian flip cannot pull them into a moving joint.
  5. Inspect likely interference around the tripod, camera, focuser and counterweight shaft.

See mechanical adjustment and movement clearance.

WARNING · Coarse latitude changes

The post-installation check is for fine adjustment. Remove the telescope and attached loads before changing the coarse latitude position. Stop if the fine adjuster meets unexpected resistance or reaches its travel limit; do not force the mechanism.

2.4 Connect power and start the mount​

CAUTION · USB-C port selection

Connect computer USB to the front-panel PC interface or the specifically labeled saddle Port B mount-PC route. Port B uses a USB-A-to-USB-C cable for data-only control, or a USB-C-to-USB-C power-and-data cable with a compatible mini PC; follow the mount-DC-first connection order. The HC controller interface and saddle Port A power output are different circuits. Never identify a port by USB-C shape alone.

WARNING · Keep the AC adapter dry

Before connecting AC power, put the supplied adapter and every mains connection in a dry, protected location. Do not use the adapter outdoors in damp conditions or when rain may reach it. See the AC adapter safety warning.

  1. With the mount's front-panel DC input disconnected, use the supplied 24 V / 200 W adapter or a verified supply meeting the WD-20EP 12–25 V DC, 10 A input specification. Check the 5.5 × 2.5 mm connector and polarity against the mount marking. Do not use the supplied 12 V PD-to-DC accessory output cables as mount input leads.
  2. Connect the AHC with the supplied controller cable to the designated controller interface. Leave its joystick centered.
  3. Connect the DC cable without straining the connector, then switch the mount on.
  4. Watch the controller and mount. If there are abnormal sparks, smoke, a burning smell, excessive heat or abnormal noise, stop using the equipment and disconnect power safely. See general safety precautions.

Leave saddle-powered accessories disconnected for the first mount-status check. The saddle ports are live once DC input is connected, even if the front-panel switch is off. Before adding or changing a saddle power cable, stop motion and make the load safe, shut down a Port B-powered mini PC cleanly, switch off other accessories, unplug the Port B computer cable if connected, switch off the mount, then disconnect the mount's DC input. Connect one accessory at a time to the correct port, restore DC power and verify its required voltage, the actual negotiated output and that the mount remains stable before adding another device. See 4.9 Power arrangements and procedure and 7.6 AHC Power monitoring.

CAUTION · AHC-to-PC cable requirement

When connecting AHC to a PC, use a fully wired (full-pin) USB-C to USB-C cable compliant with USB 3.2. A charge-only or USB 2.0-only C-to-C cable does not provide the required connection. Use the specified cable and port for this route; this does not make the mount's controller interface an ordinary PC USB input. See wired connections and AHC setup.

2.5 Connect the hand controller or control software​

On AHC, wait for the mount icon to become green. Open Dashboard and check that mount coordinates and status are being received. A powered display alone does not establish a mount connection.

For a computer, first establish a wired connection as described in Chapter 04. If using saddle Port B, connect mount DC and switch on the mount before connecting the PC cable. Use USB-A-to-USB-C for data-only control, or a suitable USB-C-to-USB-C cable for simultaneous PD power and mount data with a compatible mini PC. Configure a single controller before adding imaging or guiding applications. Avoid issuing competing movement commands from different devices.

2.6 Confirm location, date and time​

  1. Open Settings > Location. Select the observing site, or use Use GPS Location after a valid GPS fix. Press Save & Apply.
  2. Open Settings > Date & Time. Select GPS, NTP or Manual as appropriate, set the time zone, and apply the settings.
  3. Compare displayed UTC and local time with a reliable clock. Check latitude/longitude signs and the actual observing location.
  4. If software also synchronizes the mount, choose one authoritative source and check the values after that software connects.

Detailed instructions: 5.2.

NOTE · Correct observing data

Incorrect time, location or hemisphere can produce wrong target positions and coordinate-based limit behavior. Confirm the time zone is correct for the observing site, even when GPS or NTP supplies the time. Recheck both UTC and Local Time after applying settings or synchronizing from another device. Do not use GoTo until the mount's own observing data are correct.

2.7 Initial safety configuration​

Open Settings > Safety & Limits and read the current settings before changing them.

  1. Confirm GEM mode and identify EC/HA, AEB, Altitude and Meridian entries.
  2. Read the EC HA Limit east/west boundaries. Check that they are appropriate for the physical assembly and allow stopping clearance.
  3. AEB is disabled at the factory by default. If you want to use it, enable it and verify the enabled state. Read the baseline and trigger setting. AHC-guided AEB Auto Tune requires AHC firmware 1.1.0 or later and compatible mount firmware. Use the supported workflow for the actual installed load so the baseline suits the telescope, accessories and counterweights; repeat the assessment after changing the load. Complete the prerequisites before tuning.
  4. Set Horizon (lower altitude) and Overhead / Zenith (upper altitude) limits for the site and intended travel. These depend on correct time, location and pointing coordinates.
  5. Set the Meridian east/west window and coordinate it with the imaging application's flip policy and the EC HA boundaries. Check both pier sides for clearance.
  6. Confirm where to press STOP and what a safety warning looks like.

If you changed any safety value or enabled state, save it and restart the mount before relying on it. Reconnect AHC, read the values back, and complete the applicable start-up checks before normal movement. AHC showing a saved value before the restart does not mean it is active.

Details: EC HA Limit, AEB, Horizon and Overhead / Zenith limits, and Meridian limits.

Saving coordinate-limit values does not confirm that protection is active. If Tracking is forced on before startup location/time updates, Meridian and altitude protection is not yet initialized. Complete the observing-data and GoTo/Sync initialization sequence, supervising the first movement.

WARNING · Protection has limits

Safety functions do not inspect every cable or accessory. Check physical clearance even when they are enabled. Do not widen a limit simply to bypass an unexplained refusal to move. EC HA Limit provides a preventive RA travel constraint. AEB responds after abnormal loading and has limited mitigation capability, particularly with heavy, high-inertia setups.

NOTE · AEB calibration sequence

Review Auto Tune prerequisites now, but do not start it until Home, stopped-state, firmware and connection prerequisites have been met. Step 2.9 includes the final check before the first GoTo.

2.8 Complete polar alignment and confirm Home​

  1. Use your chosen polar-alignment method and adjust the base's latitude and azimuth screws. Follow any powered-motion checks in that method. If it commands the first GoTo or manual slew after power-on, verify site/time and enable Tracking first.
  2. Recheck alignment after securing the locks; aim for a polar-alignment error below 2 arcminutes (2′). Follow the load-position and stability guidance if alignment changes as the telescope rotates.
  3. When a return is required, use Motion > Go Home on AHC, or hold the mount's front-panel Home button for approximately 0.5 seconds and release it. The blue STATUS light becomes continuously lit during homing. Holding the button too long or pressing it again cancels the operation. Observe the entire motion and wait for completion.
  4. Verify the mount's Home state and actual position. Do not use Reset Home to make an incorrect physical position appear correct.

Details: polar alignment and Home.

2.9 Start tracking and perform the first GoTo​

WARNING · Pinch points during GoTo and slewing

Keep fingers, hands and all other body parts out of gaps that can close within the mount body or between the mount, telescope and tripod or pier. High-speed motion can close these gaps rapidly and cause serious injury. Check the full route, keep people clear, and never reach into the moving setup. Press STOP and confirm all motion has stopped before making an adjustment.

WARNING · Solar observation

Never look at the Sun through an unfiltered telescope or finder. Select a solar target only with correctly installed, suitable solar filters and an appropriate solar-observation procedure.

  1. If required, complete AEB Auto Tune with its prerequisites satisfied. Finish any restart/recovery and verify the resulting settings before continuing.
  2. Recheck the mount's location, date and time. In Motion, select the appropriate tracking rate (Sidereal for ordinary stellar targets), turn Tracking ON, and confirm the active state. Do this before the first manual slew or GoTo after power-on.
  3. Select a low manual slew speed and confirm a short movement in a clear area. Check direction, cable behavior and STOP response. If STOP turns tracking off, restore the intended tracking state before continuing.
  4. On AHC, open GoTo, select a well-placed target above the configured horizon, and inspect its altitude and position.
  5. Check the movement path and Tracking state, then press GoTo Target. Watch the equipment until the slew finishes.
  6. Verify the target with an eyepiece or image/plate solve. If using a solve to synchronize pointing, verify it and send Sync to the mount; a solved image alone is insufficient. Recheck the actual pointing, tracking and coordinate-limit initialization before continuing.

2.10 Park, shut down and pack away​

The default Park position is physically the same as Home, but Park and Home remain different functions. Confirm the expected destination and clear movement route before moving; see 5.9 Park.

WARNING · Park requires correct mount coordinates

Before the first Park in a session, synchronize the mount's time and observing site, then complete a successful plate solve and Sync the solved position to the mount. A solved image alone does not update mount coordinates unless the software sends the synchronization. Confirm the reported pointing agrees with the actual telescope. Home and polar alignment do not replace this coordinate check. Incorrect coordinates can produce an unexpected Park path and a collision.

  1. End the imaging sequence and stop guiding so no application can issue another command.
  2. Confirm that the expected Park destination is safe, then park the mount; check the complete route before starting.
  3. Wait for a stopped/parked state. Support or reduce any load that cannot safely be held during power loss.
  4. Shut down any Port B-powered mini PC cleanly and switch off other accessories. If a computer is connected through saddle Port B, unplug its USB cable while the mount still has DC power. Then switch off the mount and disconnect its DC input to de-energize the saddle ports. Only then disconnect saddle leads without pulling or twisting their connectors. Remove the telescope and counterweights while supporting each item.
  5. Dry any moisture and return the mount to its fitted case once the equipment is dry.

See 5.9 Parking and shutdown for Park selection and next-session checks, 5.2 for time synchronization, and 5.5 for pointing synchronization. If coordinates cannot be verified, stop movement and shut down safely with the load supported as necessary; do not command Park with uncertain coordinates. For an unexpected result, use Chapter 08.