Grandson loves Mark and all of the stuff he does. My wife buys him the build boxes and works with him to assemble them as a Grandma day every couple of weeks. He built the disk launcher yesterday and promptly lost a few disks in testing. I started designing a replacement and thought I should check on printables and found your design so printed him a full build plate full of replacements. I guess his Mom is going to be finding them all over the house now but he should have a lot of fun launching them.