adjustable height bench

[Steve N]

I'm sorry but I think that you're going down the wrong path here.  I would hazard to guess that virtually every woodworker on this forum has a fixed height workbench and for a good reason.  Workbenches are subject to a lot of stress, I think that would be difficult to construct a practical bench that could vary the work height and not start wobbling after a short while.  We also have to work at various heights and and have found solutions that don't require raising our intentionally heavy bench.  As an example, I have a separate box that can easily be clamped to the bench to give a higher work surface that can be easily stored when it is not in use.  I also built what is sometimes called a "bench on bench".  It's simply a small auxiliary bench that clamps to the top of the workbench that has a front vise and dog holes that I sometimes use for dovetailing. I think that you're time might be better spent building simple boxes that raise the work.

I know several people including myself with adjustable height tables in the shop. I don't think many are using them for doing heavy work at any level. I know I just use mine for assembly, and finishing. But realistically the only "heavy work" I can think of is planing where you are pushing against the upright legs. Pretty sure all the heavy planning folks already have a traditional bench. Power tools, sawing and chisels don't require a heavy duty bench. If you do, you're doing something wrong

[Tapper]

I've seen several tables built on those lift carts from HF, usually if you try to get more than 4' x 4' it gets tippy pretty quick. I suppose you could use one on each end of a bigger table, but then you still need 2 people to work the lifting process, or as soon as you put one end up in the air, you are back to tippy, or ejection of one cart or the other. I've looked at them, and Beefy would not be in my description. If you screwed the top to those tables I believe any weight at all would cause the tops of the lifts to get ripped up if they were screwed to the part trying to take off.  

Just to clarify, in my post I was not advocating building a workbench on top of the Harbor Freight lift. My suggestion was that you could use the lift to easily raise the workbench to the level you desired, slide spacers under the four legs, retract the lift and leave the bench in place at the desired height.

As I said, the lift is useful for many other tasks around the shop as it has casters and is very mobile.

Doug