At the corners of every grid add another screw, and another , and another, you get the point. This part of the build was really boring until my piece of worthless junk cordless died, I think the battery is shot. Well time to pull out the old standby, my old brace. This 60 year old brace never lets me down. It works great every time I use it and I have yet to need to replace the batteries. Needless to say the brace saved the day, whoa that rhymed.