I've pretty much got the basic structure decided on for my mobile base. I'm going to use 6 of these: moble base feet.gif from McMaster-Carr rated at 500 lbs each. (Yes, overkill) 1/2" threaded, 13 tpi. Base is slightly over 2 3/4" diameter. I'm afraid the regular T-nuts won't hold up to the weight. I'll have almost three 4X4X8 Douglas Fir lumber, four of the Grizzly G8172 casters G8172.jpg, about 22 lbs, two 30" sections of black pipe, some end caps and washers, plus I'd like to build some storage under the right extension. This will not be base to extension table high as I'll have the DC ducting running there also. OH! and a little over 600 lbs of saw and torsion box extension table. So I'm guessing I'll be between 800 and 950 lbs by the time I'm finished.
Anyway, I was looking for something like the black pipe floor flanges to use for mounts, but the threads per inch on the pipe is not 13 tpi. The OD of the 1/4" pipe looks about right. So, any ideas on something that is heavier duty than the T-nuts? I did see some cast alloy ones at McMaster-Carr that have 3 mounting holes on the flange, but I'm afraid those won't be heavy duty enough either. There are no load ratings on them or the T-nuts.
As always, any help or ideas would be greatly appreciated! Jim.