A rolling work table is a versatile addition to any shop. It may not be quite as stable as one with a fixed-base, but its mobility more than makes up for this shortcoming. It can be used as a portable work surface or as an auxiliary table where no other space is readily available, it can follow you around the shop and when you're finished with it, it can be rolled out of the way for storage. The table I'll describe goes a step beyond in that it easily breaks down for more compact storage in shops where floor space is at a premium. A recycled five legged office chair makes an ideal base. They are more stable than the four legged version. Office chairs are designed to support more than ample sized people, so capacity should not be an issue. Outdated or worn chairs are frequently available for little or no cost. There are a number of different styles that can be adapted for a table, but the two I prefer similar to the one pictured. It has an industrial plastic base and the other a solid aluminum base. These are ideal because the pedestal fits into a 2 ½ to 3 degree tapered hole in the base. A few careful taps with a hammer on the bottom of the pedestal quickly removes the complete upper assembly leaving the base ready to use. The tapered hole also facilitates the breakdown for storage later on. I recently built two rolling tables to support propane forges at hammer-ins. Because of the height required, I was somewhat concerned about their stability, but they performed perfectly. The pedestal is made from a length of 2" pipe (1 ¾" inside diameter). Before beginning the taper, I recommend that you weld a piece of ¼" flat iron vertically across the middle of what will become the tapered end. This is not absolutely necessary but will facilitate the takedown by giving you a larger surface to strike. If you don't have access to a metal lathe, the taper can still be achieved relatively easily with a "third-hand" stand and a 2" belt grinder equipped with a tool rest. Set up the stand as pictured and take an educated guess at the angle. The correct taper measures about 4" long and the finished thickness at the end of the pipe is approximately 1/16" all way round. The stops on the stand help maintain a constant angle and one foot on the base while grinding keeps it in place for the whole operation. To speed up the grinding, start with the coarsest belt you have. Turn the pipe continuously as you grind, keeping the taper as even as possible. Using frequent trial and error fitting, adjust the angle until you are right on. Change to a finer belt (120 grit) and continue grinding until the post fits snugly. Size the tabletop to suite your purpose. Both of mine measure 1/8" x 13" x 22". Cut about a 7 ½" section of 1 5/8" diameter pipe to nest inside the pedestal. Then weld a 1" section of the 2" pipe onto the end of the smaller pipe so that the pedestal will fit between the table supports. The two supports are 1 ¼" x 18" x 12 ga. square pipe with their ends tapered at 45 degrees. Before welding them to the nesting pipe, drill a slightly undersized hole just clear of the 2" ring and force in a half-inch or so piece of ¼" mild steel rod leaving ¼" or so exposed for a registration pin, then tack weld on the inside. Clamp the two supports to the table with the nesting pipe assembly centred and perpendicular to the plate. With the registration pin pointing up the middle of the length of plate. Weld the whole assembly together with a few short beads generously spaced in order to reduce any chance of the heat distorting the plate. If desired, the top can be drilled and the holes countersunk for attaching with flat head bolts as I did with one of my tables. Determine the table height you desire and mark the pedestal, making sure to allow for the height of the base and wheels. Mine are 34" off the floor. Drill a ¼" hole just touching the underside of the mark. Cut the pipe to length then file the hole out to accept the registration pin. Weld a piece of metal onto the pedestal to reinforce the location where you wish to locate the bolt clamp to hold the tabletop securely on the pedestal. Drill and tap a hole for the bolt. For convenience, weld a "T" handle onto the bolt. To assemble the table, insert the pedestal in the base with the registration hole pointing to one of the legs. For my application, this ensures that one end of the table extends over a leg. This end becomes the front of the table because it is in the most stable location. Align the registration pin, and insert the table-top assembly into the pedestal. Lock the assembly in place with the bolt and the table is ready to use. If you are using the top plate as a support for a larger metal or wooden top, this consideration may not be important. To disassemble the table, remove the top assembly. Turn the bottom assembly upside down and while holding or otherwise supporting it off the floor, tap the bottom of the pedestal lightly with a hammer until it comes free. If you didn't weld a piece into the bottom of the pedestal before bevelling it, it is difficult to impossible afterwards because it is so thin; impossible at least for me. Nevertheless, you can make a punch to do the job, by carefully sizing a short section of pipe to fit inside the pedestal and contact the 1/6" flat on the bottom of the taper. Lightly tap the punch to remove the pedestal. My punch looks like a large mechanic's socket. However, this is a poor alternative because you have one more loose piece of equipment to keep track of.
Great idea, never enough work space/tools in the shop. I've got a old chair frame like that sitting in the corner. New project, just what I need