Spring loaded feet?

[Larry Edgerton]

I just delivered a pedestal table and I built the base on my shaper so I knew the feet were perfect. I had to shim it at the house so it would not rock, but the owner called and when he moved it he had to reshim. He was wondering if I had any ideas on how to cure this problem as it is a marble floor and not at all perfect.

I thought about recessing those little nylon threaded feet, but the table is too heavy to mess with that every time and I would not want them to show so they would have to be recessed. The table is too ridgid to flex, have to think about that next time.

So.........


I had an idea of boring the feet for springs, something like a valve spring but not that heavy duty, and then turning some plastic inserts so as not to mar the marble. Not absolutely sure it will work, and of course I would have to try it out on a prototype so it could be an exercise in futility.

I thought about a heavy foam rubber feet as well but do not think it would suvive pulling the table out to clean.

Thoughts, Ideas, and Experiances?

Thanks, Larry

Larry

[John Sanford]

Springs/hydraulic cylinders are really the only way you can get a no-muss no fuss solution from the owner's standpoint. The problem with either is three fold. First, you have to capture the floating feet so they don't fall out. Not a big problem, but still a consideration. The second problem is simply dialing the appropriate spring force in. I'm sure there are tables and formulas and such for doing it, but do you have access/familiarity with those, or will simple trial and error be the most productive route given that this is essentially a one-off?

The third problem, and this is the biggie, is this:

Unless you can be assured that the imperfections in the floor are ALWAYS in the same orientation, moving the table is simply going to result in the top going out of level. You might be able to dial it in so the table doesn't rock (much), but it won't be level. Cars are the perfect example, they float on four spring systems. Put a car on a slope, it doesn't "hunch down" into the slope or otherwise try to level itself. The springs, at neutral, keep the wheels in a certain relationship to the car, pretty much without regard to the car's relationship to the ground. The only exception is if you flip the car upside down, and then the relationship will change, BUT it will change the same for each wheel assuming a 50/50 front/rear weight distribution.

So, ultimately, what you need is some sort of adjustment system. In theory, it's pretty simple, in actual execution, not so much. In addition to garden variety leveling feet, you can do all sorts of mechanical/hydraulic/electric/pneumatic solutions that would involve a whole lot of work on your part. Some of these would be pretty cool such as an air piston in each leg connected to a battery operated pump, valves and a level, with some snazzy software that actuates the pump and controls the valves in order to automagically level the table when it's moved.

Or you can cut a passel of assorted shims that are sized to be a discreet as possible under the table legs, and give them to the owner.

[Rick Lizek]

http://www.jacobholtz.com/tableshox-...-levelers.html
look up spring loaded furniture levelers...
The link shows a 500 lb rated set of levelers.

[Larry Edgerton]

Thanks Rick. I had not seen those. They are too big for this particular table, but I will keep bookmarked for future reference. The legs on the one I just did are too thin to be able to recess those, and they are too ugly not to hide, but it does validate the idea. I am going to order a set to play with.

I called a outfit that does just springs yesterday and the guy says I can get what I need but I need to weigh the table to get a spring rate. I am thinking shoot for a spring rate that is 33% or a little less of the weight of the table, assuming a four leg table, and I was thinking about 1/4" projection. I am thinking that way the two legs that have more weight will collapse those two springs and the other two will keep it from rocking. I may be able to get by with two springs and two fixed as well.

I'll play with the idea, but in the mean time I will take the customer a shim assortment as John suggests.

[Tom Welch]

Yea thanks Rick. Just what I needed.

[Myk Rian]

Put feet with threaded shafts in. Such as a washing machine or refrigerator.
Table gets moved. Foot gets turned. Table sits steady.