#Cylo #video of diamond-turning a mirror after initial rough milling. #optics #manufacturing #toread
on 02025-12-10#Cylo #video on #precision #flexure #mechanisms, starting with “wobble pins” connected with “pairs of notch hinges”, and cascading two springs of different stiffness, so you apply a large displacement to the weaker spring, which produces a small force in the “colinearly attached” weaker spring, which then moves a four orders of magnitude smaller distance. From Smith and Chetwynd. He proposes the “diving board” flexure, where a force on the end of a cantilevered beam produces a small displacement on the opposite side of its fulcrum, the beam being pinned at its end to form the cantilever support with the fulcrum, the displacement ratio being (16/3)L₂(L₂ + L₁)/L₁², thus asymptotically proportional to the ratio of the squares of the lengths, enabling a large transmission ratio in a small package. His realization uses a cross-leaf flexure for the pin, a bearing ball in a screw for the fulcrum, another bearing ball in a screw to bear on the end, and a wobble bar to a four-bar parallel-movement flexure for the output, which he’s measuring with an LVDT. He even has antibacklash flexures on the threads of his screws.
on 02025-12-09#Cylo #video on books about #machining #precision #mechanisms: Richard Moore’s Holes, Contours, and Surfaces, which is largely about operating jig borers; Douglas Blanding’s Exact Constraint: Machine Design Using Kinematic Principles; CRC Press Basics of Precision Engineering, edited by Leach and Smith; Balasubramaniam, Sarepaka, and Subbiah’s CRC Press Diamond Turn Machining: Theory and Practice; Rowe’s Hydrostatic, Aerostatic, and Hybrid Bearing Design; Kittell’s Precision Mechanics; Evans’s Precision Engineering: An Evolutionary View; Smith and Chetwynd’s Fundamentals of Ultraprecision Mechanism Design; Slocum’s Precision Machine Design; of course Wayne R. Moore’s Foundations of Mechanical Accuracy; and Dave Arneson’s blog post listing “50 tidbits”. Smith and Chetwynd is hard to find.
on 02025-12-09#video #toread on #Cylo’s thrust air-bearing prototype. #precision #mechanisms
on 02024-09-15#video on #Cylo problems in #precision #optics #manufacturing #mechanisms: “Nanoscale air bearing vibrations cause surface finish issues in diamond turned surfaces.” 50 nanometers of vibration gave a “hazy” surface finish, although you’d think it wouldn’t.
on 02024-09-15#video on #manufacturing #kinematic-coupling for air bearings for #precision #mechanisms. #Cylo ground a three-planed vee out of W-1 tool steel to place a bearing ball in, with slots in the sides for access, then hardened and polished it. I wonder why he didn’t just use three bearing balls? He states (incorrectly, I think) that the small contact surface area between the ball and the planes produces lower static friction.
on 02024-09-10