https://www.youtube.com/watch?v=nPAKYBpI5kc https://www.youtube.com/watch?v=eksLjDsfKrE "Marblevator, Mechanisms" is the latest in my Marblevator series of marble machines and features the quickest marble lift mechanism I've ever designed. My fascination with gears, mechanisms, marble machines and history formed my inspiration for this model. The model incorporates two antique mechanisms; a "Peaucellier–Lipkin" straight line mechanism (vintage 1864), and a "Whitworth" quick return mechanism (vintage 1800's) that, when combined as they are in this design, provide a straight line slow ascent, and a straight line rapid descent. In this model, these combined functions are use to slowly raise a bucket containing a marble (an 8mm ball bearing) to the top of a short, built in, track, dump the marble onto the track, rapidly lower the bucket to pick up the marble at the bottom of the track, and then repeat the process. I've included a sketch illustrating the method I used to compute the bar lengths for the straight line mechanism. If you have any questions about the illustration leave a comment and I'll do my best to answer. As usual, I probably forgot a file or two or who knows what else, so if you have any questions, please do not hesitate to ask as I do make mistakes in plenty. Designed using Autodesk Fusion 360, sliced using Cura 3.3.1 and printed in PLA on both an Ultimaker 2+ Extended and an Ultimaker 3 Extended.