This instructable is going to show you how to make use of old cardboard tubes to make a structure that can be disassembled, in my case it was for a coffee table for a friend.
Materials needed for this are as follows:

-Marker
-Measuring tape
-dremel with diamond cutting disc
-metal file
-saw to cut small wood stock
-sandpaper
-Carriage bolts or hex bolts
-T nuts
-drill with drill bits
-cardboard tubes

Step 1: Planning Your Cuts

Measure your tube and find out where you want to make your first cuts to use as a pattern.
Depending on the thickness of the material you are going to be using, helps determine your cut depth and size.
You can use what ever size wood or stock for the lower cut on the tube. This cut must be matching on the other side of the tube as it will be holding stock.

Step 2: Cut and Drill

After cutting all 4 legs do a dry fit of everything, legs tabletop and inner wood threw eyehole. Minor adjustments may be needed.
Use a metal file and some sandpaper to ensure the wood for the eyehole fits snug but removable.
Drill a whole the size of the carriage bolts that starts about 1" from the corner of the tabletop and goes threw to the wood into the wood in the eyehole.
Countersink the hole that was drilled on the tabletop of desired.
Remove wood from eyehole and complete the drill if needed.
Attach T nut on the underside of the wood for the eyehole.
Test out the fit once again except this time with the carriage bolts in.
A quick drawing demonstrates a sectional of how the cardboard tube (leg) attaches to the tabletop surface.
By putting a T nut on the bottom of the wood stock in the eyehole, allows for a clamp like bond when the hex bolt is threaded from the top of the tabletop surface.

Step 3: Finish

I made this with intentions of making a coffee table on low budget and or with found recycled materials. The top was from a recycled crate, witch I removed a diagonal slat and that allowed for a shadow box type frame. Cut and place in piece of plywood 1/4" and then covered with marble tile that i rearranged into a mosaic, Also reclaimed. The only thing that was bought was the bolts and T-nuts a cost of less than 5 Canadian dollars. Worked perfectly, and they loved it!
(was painted brown for the final finished product)