2

I have inherited a DIY build and I have some doubts about its design. Have a look at the following diagram: enter image description here

1 is the linear actuator. It's quite beefy 2000 lbs 12" stroke. It is installed in an aluminium channel. 4- Is a carriage, essentially a box section with little rollers on all sides, so it has no play within the channel and moves quite smoothly. This is connected to the actuator's rod. 3. Is a flat steel bar that links to an identical channel (2) and carriage assembly, though this doesn't have an actuator in it.

The system is supposed to lift a max 220 lbs load that is evenly distributed along the bar.

My questions are:

  1. While there don't seem to be any bending forces to the actuator itself, is it a safe design, as far as longevity of the components goes?
  2. is there anything I can do in channel 2 to support the system, e.g. a spring at the bottom, etc. to address any design problems?
John Lane
  • 209
  • 2
  • 7

1 Answers1

2

As a quick basic estimation approach we annotate the following:

  • The length of bar 3 = L

  • Top and bottom bearing force on each box $F_b$

  • The height and width of boxes 4 and its counterpart on channel 2 H and W. $$ \Sigma M=0 ,\quad 220*L/4 = H/2*4F_b \rightarrow \quad F_b=220*L/8H $$

Now you have to figure if the bearings and their connections are okay to take this load multiplied by a safety factor of say 3.

kamran
  • 23,517
  • 2
  • 22
  • 42