Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations SDETERS on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Recent content by WestyTea

  1. W

    Root cause of harmonic oscillation in telescopic column

    The frequency does not change with height or position. However, I wouldn't necessarily expect it to as the reaction torque arm is constant, ie the width of the column, as it is being pulled down by two belts on each face of the column. FYI the travel of the column from nested to full extension...
  2. W

    Root cause of harmonic oscillation in telescopic column

    Thanks I'll look into it. I took some IMU measurements yesterday and I think I may have found the root cause. I believe it's a function of the interaction between the friction between the blocks and columns and the offset payload: The offset payload means there is a higher friction force on...
  3. W

    Root cause of harmonic oscillation in telescopic column

    Thanks for the replies Non-linear for sure. There are a second set of smaller blocks lower down fixed to the inner tube, reducing the likelihood of racking (kitchen drawer), but doesn't rule it out completely. An offset payload could be creating a gap for sure. We can shim the blocks closer...
  4. W

    Root cause of harmonic oscillation in telescopic column

    Hello All, I am working on a telescopic column. The design is two square Aluminium tubes supported by internal Acetal wear blocks. There is a payload on the inner tube and it is driven up and down, the external tube is static. I am frequently getting a 9 Hz vibration mode occurring as I drive...

Part and Inventory Search