Lab jacks from Siskiyou Corporation offer an unmatched combination of stability, platform parallelism (over their full range of travel) and large adjustment range. This makes them an ideal solution for applications that require height adjustment of heavy components, such as large lasers, or vertical positioning of entire optomechanical sub-assemblies.
Traditional lab jacks employ either pantograph or scissors adjustment mechanisms, both of which exhibit diminished mechanical rigidity and stability as they are expanded. The Siskiyou approach utilizes three thick hinges, one placed orthogonal to the other two. This innovative configuration actually becomes more stable as it is expanded (since it becomes a box), and also tightly constrains the top platform motion so that it always remains parallel (to within 1 milliradian) to the bottom plate. Furthermore, a combination of low backlash pivots, a rolled brass leadscrew and a large adjustment knob deliver easy, stiction free adjustment even under heavy loads.
Siskiyou offers these high stability lab jacks in two standard models (with custom versions available upon request). The model 540 is adjustable from 2.4 inches to 4.25 inches, and has a load capacity of 60 pounds. The model 560 can be adjusted from 3.0 inches to 6.0 inches, and has an 80 pound load capacity. Both models provide both imperial and metric compatibility in a single unit, delivering maximum utility and value. Specifically, for each, the top plate contains an array of ¼ x 20 tapped holes on one inch centers, while the bottom plate has M6 tapped holes spaced on 25 mm centers. So, simply flipping the lab jack over switches it from imperial to metric operation.