I found that the print head cradle on my A8 was quite flexible and sagging 5-10 degrees and was very unstable. This is a quick fix for the issue to make the cradle more rigid and support the weight of the print head assembly .
The steel cradle on mine has a thickness of 1.5 mm and when square measures 55 mm from outside edge to outside edge. The brace was designed to fit my printer specifically and may need adjustments to fit yours. I did have to sand the channels a bit as they were slightly too tight . The brace needs to be a firm fit and will hold more firmly in place due to the outward flex of the steel cradle .
I printed this flat on its back so it didn't need supports