[philso]

Please ensure that your design and your manufacturing methods allow you to adjust the spacing of the vertical rails so that they are locked at the correct spacing for the lift carriage and so that the vertical rails are the same distance apart at the top and the bottom. Otherwise, your lift carriage will not move smoothly or may jam at one end of the travel.

You may also want to consider the various height limitations, direct and indirect, especially if your team intends to do well.