This video gives you assistance, and how to adjust info for the travel limits on, Liftmaster, Chamberlain and Craftsman brand garage door openers with the manual adjustment screw. Including belt drive, chain drive and screw drive models all have the same instruction. For close and open adjustments. This is for the location that your garage door stops. These motors have a safety shut off. If it over heats it will shut down for about 15 min. This video does not include the models that have a program button you hold down to set the travel limits.
Zinc plating in a mixed chloride acid zinc solution and passivating using a Cr+3 chromate.
Go here to learn more: https://www.epi.com/cr-3-chromates/