Adjustable Height Table Hardware

Ideas for ways to let a kitchen table be raised and lowered. January 18, 2011

I am a furniture maker in Annapolis, MD and I have a commission to make an adjustable height, solid wood kitchen table. The table is to be about 4 ft x 4 ft square and a single pedestal support. The amount of travel desired is about 5-6 inches. Has anyone here done anything like this before? Any suggestions?

I have come across marine tables and helmsman chairs that use gas-lift cylinders and I wonder if something like that would be appropriate and possible to customize into a hardwood table like this. I can also envision something like a camera tripod with rack and pinion and crank handle. Lee valley has something like this but not sure if it looks stout enough. Also, with gas-lift cylinders, how long do these mechanisms last?

I have questioned why the client needs/wants the up/down feature, but the decision is pretty set on it. The client is at least exploring the feasibility.

Forum Responses
(Furniture Making Forum)
From contributor S:
My first thought is a 2" all thread in steel or brass - perhaps Acme threads - and they can just rotate/spin the top to the desired height. Then, I thought you could do wooden threads on a larger diameter - 4-5" - wood post with female threads at the lowest setting and near the bottom of the base post. Rotating would still be the adjustment.

The problem will come with stability on a single point attachment - camera tripod, etc. A 4' square table on a 2" or 5" post will be a little bouncy out at the edges. I don't know how to remove that, short of going to a 12" or larger post. Seems that Hafele or Mockett had something like this for the carpal tunnel avoidance strategy popular a few years back.

From the original questioner:
I did find a similar telescoping pedestal from Mockett - and you're right, that probably would be the smoothest way to go. The table needs to move around though, so I'm not sure they'd go for something that has to be plugged in.

I spent some time learning about locking gas springs, like those used in hospital tables and office chairs, and I think they would work but the gas spring would probably have to be replaced after 5-10 years and that just doesn't seem acceptable. Any thoughts about trying to incorporate a rack and pinion set from someplace like Mcmaster-Carr into a telescoping pedestal? I could make the sleeves as wide and stout as I need and fit in the rack and pinion accordingly. Basically making a custom, beefier version of what Lee Valley offers. I just don't know the nuts and bolts of how to do this. Don't some drill presses use this mechanism for table height adjustment?

From contributor J:
I once had an old cast iron drafting table base that had a rack and pinion gear for up and down. I used it as my first attempt towards and adjustable work bench. The mechanism worked well enough, but the weight of the bench top made it nearly impossible to crank up, and it came down too fast. I suspect you will have the same issue with a 48x48 top. A guy I know did an adjustable work bench last year built around an ordinary little scissor jack from a car and it worked great.

From contributor W:
What about using the mechanism like that to raise and lower you planer head? My DeWalt has four posts that are chain and gear co-driven by the hand crank. The four posts would give as wide a base as possible. You could play with gear ratios to balance speed and power needed to raise and lower. My planer is rock steady. You could even incorporate a lock mechanism.

From the original questioner:
Iím now thinking about using a steel compression spring combined with rack and pinion (or possibly even a simple peg and multiple hole system) and whether that would work. Spring would be under the main up/down post. This would help carry the weight when re-positioning the table height, but I imagine at the highest position you'd have to do some additional lifting and at the lowest some additional pushing for a peg and hole system; with a rack/pinion the cranking pressure required would be greatest near the highest and lowest positions. Any thoughts on this compression spring idea?

From contributor J:
Just make sure their budget can compensate you for the engineering involved! As I learned, building the prototype and the real thing as the same piece is not the best way to go.