Tool for calibrating a Laser Collimator

Skylabs NZ has developed this easy tool for calibrating a laser collimator.
 
You will find a complete guide for collimating a Newtonian telescope in our blog article "How to Achieve Accurate Collimation of Newtonian Telescopes".
 
Follow these directions in order to calibrate your laser collimator:
Place a circle sticker on a flat surface as far away as you can. A door at the end of a long hallway will work.
Place the laser collimator on top of a V-shaped surface and adjust the height. I use a 3D printed model on top of a tripod. It is very handy but a piece of timber will also do the job.
Turn the laser collimator. You will notice that the red dot draws a circle when you rotate the laser collimator. Place the sticker in the center of that circle.
Rotate the laser collimator and adjust the three screws in order to move the projected laser beam in the center of the sticker.
This is an iterative process. You may need to move the sticker and repeat steps 3 and 4 until the laser beam does not move when you turn the collimator on the rig.