Cryogenic positioning stage: High resonance
Introduction This XYZ positioning stage is specifically developed for cryogenic applications where high resonance frequencies are required. Furthermore this stage can be used in a scanning mode for small movements around a given set point. Pro’s & Con’s Operational down to 1 K High resonance frequency Sub nanometer resolution scanning mode Play/backlash free Antimagnetic materials […]
Sag compensated contact pin
Introduction Typically struts and leaf springs demonstrate a parasitic sag-movement when moving sideways. In some cases this parasitic motion is unwanted. Then a rigid tip can be implemented on the elastic element. By designing the proper tip radius, the parasitic motion can be perfectly compensated resulting in a straight-line guided motion. Formulas The kinematic behavior […]
Zero stiffness linear guidance
Introduction This sheet provides a design of parallel leaf spring guidance with adjustable stiffness from positive to negative, to benefit its application. Concept A parallel leaf spring guidance is a linear guidance which comprises no play and its (relatively low) stiffness is well predictable (see Precision Point sheet: 2 Leaf springs in parallel). A buckled […]
3 Parallel & tangential folded leaf springs
Introduction 3 parallel & tangential folded leaf springs are often used as a z, Rx, Ry fixation. Each leaf spring contributes to the total stiffness of the setup. This sheet describes the stiffness and stroke of the individual and the combination of 3 parallel & tangential folded leaf springs @ 120º. Individual stiffness The stiffness […]
Leaf spring/flexure: Reinforced
Introduction Flexures or leaf springs can be used for play and friction free motion. A downside is stiffness and to minimize the needed force, the flexures are made slender and thin. Smart reinforcement of flexures and leaf springs can help to keep the needed motion-force minimal while the flexure or leaf spring is made thicker, […]
Reinforced strut
Introduction Struts are often used for connecting two bodies in 1 DOF (x), while keeping the other DOFs free. In many cases the function of a stiff element with two hinges is desired. This is achieved by reinforcing the midsection of the strut. The poles of the hinges are located at the center of the […]
2 Leaf springs in parallel
Introduction 2 leaf springs in parallel are often use as a (quasi-) linear guidance were play must be eliminated. Pro’s & con’s Play/backlash free Well predictable stiffness ($C_x$) (small) Stiffness in direction of movement Parasitic displacements ($u_z$) Short stroke Elimination of parasitic displacements Through a double parallel leaf spring (in series) the parasitic displacement can […]
2 Elastic hinges in series (leaf spring)
Introduction 2 Elastic hinges or flexure hinges in parallel form a reinforced leaf spring and can be used in monolithic structures to be able to have relative motion or displacement. This sheet elaborates on the design of these flexure hinges to acquire the desired stiffness for your suspension. Usage Used as a stiff alternative ($C_x$) […]