I made this originally for my Rolling Thunder handle, which will be another instructable very soon.
Step 1: Get your parts
Pretty simple setup really:
I used one 3/8" eye bolt, 4" long, rated to 325 lbs. Cost about $1.50
One 1.5" by 6" nipple, as its called in hardware terms.
Just a threaded 6" long pipe, 1.5" inside diameter. Cost me about $4.00
I used 1.5" diameter pipe because my gym's olympic plates have a 2" inside diameter, so these just fit.
One 1.5" floor flange, which cost about $10.
One 1.5" cap, which cost about $3.
All of this was purchased from home depot, I'm sure if you look around you could find a better price for most of it.
I drilled a hole through the cap with a power drill and a 3/8" drill bit.
Then I put some epoxy on the threads of the eye bolt just to make sure the nuts didn't get a mind of their own and start to unspin, and attached it to the cap.