The knobs on my washer and dryer have both been busted long enough! A8 saves the day! PLA is slippery, so after a few misses, I decided to add a small strip of rubber in the design. I increased the size by 1mm then on the washer/dryer gorilla glued a couple small pieces of belt from my printer on the flat part where the knob attaches. The knob fit on easily but snug, I was pleasantly surprised by the results.