Mount axis calibration
Setting up the Home position
The aim is to set the mount up as accurately as possible in order to minimise issues later. It can be done at home as part of a test run before imaging, preferable on a level concrete floor.
First, set up the tripod on a solid floor and ensure its level.
Sit the mount onto the tripod.
Adjust the mount’s RA & Dec dials first. The EQMOD Project has instructions on how to set the dials. Re the instructions, I prefer at step 9 to set the Dec to 0. Then, in step 10, rotate to 90 deg. Tighten the dial screws.
Setting the mount up to its the initial home position before applying power:
- Level the Tripod making sure that the single-leg, next to the black square pin, faces the Celestrial Pole while ensuring the tripod remains level after each Tripod movement. (see Polar Alignment information)
- Secure Mount to the Tripod.
- Adjust RA so that dial aligns with 6 and tighten clutch.
- Adjust Dec so that dial aligns with 90 and tighten clutch.
- The Mount is now in its Home Position.
- Power up Mount
Checking alignment of Compass Stick
A cross-line laser level can be used to check the Compass stick and ensure the Mount is aligned with the laser line.
First, attach the stick to the mount and aligned the cross line laser level to provide a vertical line along it’s South to North axis, and up along a wall (or white door in my case)
The red line follows the centre line of the stick and hits the middle of the square black pin near the rear leg (that should point to the south)
The level on the Compass Stick can also be checked at this time for accuracy (and fixed if needed).
Checking alignment of the Telescope
Place a post-it sticker with a black line on it, high up on the door, to provide a guide for the line of the laser level to ensure the laser level was had not moved once the Compass Stick was replaced with the mount and Telescope.
The tripod and laser level are now aligned and ready to be checked against the Telescope.
After removing the stick from the mount, double-checked the vertical laser line was still on the post-it sticker line as well as on the south line marked on the tripod and also in the middle of the black peg in the top of the tripod.
Place the Mount and Telescope on the tripod.
Ensure the laser line is in the middle of the OTA and imaging equipment along its full length. If not, recheck the above steps. (ignore the horizontal laser line)