I'm building a lift bed in a van. The basic idea is that each corner of the bed is mounted on a linear track actuator, bed goes up, bed goes down.

bed lift on actuators

I want to be able to control each actuator independently so that I can level the bed if parked on a slight incline. The problem with this is that as the bed becomes un-level relative to the van the mounting points are going to need to be able to have some play to them. Quick napkin math says that on a 10º incline, I'd need 1.3" of horizontal play on the long axis and 1" on the short (@20º it's 5"/3.6").

My initial idea is to just mount each corner in the middle of an "X" of 100lb springs, but there has to be a better solution! Any ideas?

  • 1
    $\begingroup$ The easy solution would be three actuators. Three points make a plane, four points make it crooked. If you must have four actuators, three of them would need to have ball joints at their bottom in addition to each having a joint at the point of contact with the bed frame. $\endgroup$
    – towe
    Nov 9, 2022 at 12:33
  • $\begingroup$ use short chains to hang the corners of the bed $\endgroup$
    – jsotola
    Nov 9, 2022 at 16:20
  • $\begingroup$ Don't forget that the actuators will no longer be totally vertical in this situation. At least 2 of them will need to be able to tilt at a slight angle. $\endgroup$
    – Drew
    Aug 7, 2023 at 15:02

1 Answer 1


A ball and socket joint, like some suspension or steering joints.


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