As you can see from the pictures of my shop, being able to move stuff around, and moving machinery into and out of the shop as needed is a necessity. I came to the realization that I was going to have to make more than just my table saw mobile when I decided to acquire a bandsaw. However, good mobile bases run $50 apiece and up, and I needed four of 'em! I was able to score one used from one of the SEMIWW members, but I still needed three more. In addition, the retractable casters on my Craftsman contractor's table saw were not very functional. When lowered to allow movement of the saw, their design prevented them from swiveling freely, and I was usually sliding it across the floor on non-swiveling casters.
I figured I could make one cheaper, and decided to make one for my table saw. I considered making it out of angle iron, but fabrication would be a problem (I don't weld) and angle iron is EXPENSIVE!
I decided instead to make it out of 2x4's, using angle iron to create "pockets" for the tablesaw legs, fitted with a couple of swivel casters, and using a lever-hook on wheels to lift and move the "stationary" end of the base.
Most mobile bases have two fixed wheels at the "rear", and swivel casters at the "front". However, I knew that given where I store my table saw, being able to slide it sideways was going to be a big help in moving it around. Most commercial mobile bases (like the Shop Fox that I bought used) have some mechanism for locking the front end, relying on this to immobilize the base once it's in position. In my design, since I had casters on the back and the front would rest on the floor, I would instead need to clamp the rear down to stabilize the base.
The following pictures should be sufficiently self-explanatory. I've added notes to help you create one for yourself. Feel free to contact me if you have any questions.
This is the completed base, before attaching the jack screws to secure the rear. Note the angle iron "pockets" and the diagonal 2x4's that mount the rear casters. You can also see the u-bolt at the front that is used to lift and move the base.
Here is a shot of the underside, again showing the angle-iron pockets and the swivel rear casters. The angle iron is hot-rolled 2" x 1/8" and cost about $10 for 36" which was enough for the four pockets you see here. When I make the next base for the drill press, I'll use 2" x 1/8" hot-rolled steel bar. I cut the angle-iron using a cheap ($10) 4 1/2" angle grinder I bought from Harbor Freight fitted with a 1/8" cutoff wheel. Lots easier than using a friggin' hacksaw, but by the time I had these four pieces cut and finished, my shop was covered in gritty black residue from the shower of sparks that the angle grinder produces as it cuts through the steel. Not recommended. Better to take a sawhorse, a 2x4 and some "C" clamps into the yard or the driveway for this kind of activity. The angle iron is mortised into the 2x4 frame so that the frame can set flush on the floor. The 2x4 diagonals that mount the swivel casters are positioned 1/2" below the 2x4 frame, which allows the casters to extend 1" below the bottom edge of the frame. This dimension was determined from the Shop Fox mobile base which also provides 1" ground clearance. The 2", hard rubber 150 lb capacity casters cost $2.68 each, part number FLT-25124H available from JL Industrial supply.
Close-up of the angle-iron "pocket" and swivel caster.
This shows the detail of the 1/2" jack screws that are affixed to the rear of the base, and screwed down against the floor to secure the base once it's in position. The one on the left is completely assembled. The one on the right is "exploded" to show the details. From left-to-right we have a 1/8" piece of rubber gasket material (available at most hardware stores in 5" square sheets), a 1/2" PVC plug, a 1/2" PVC coupling (NPT on one end, glue-fit on the other), a thin ring of 1/2" PVC pipe, a 1/2" "E" clip, a 1/2" Tee nut (available from McMaster-Carr as part number 90975A033, about $10 for a pack of 20 plus $4 shipping), a 6" length of 1/2" threaded rod, a 1/2-13 jam nut, and a cast iron cross knob, available from JL Industrial as part number NWT-17507H for $4.50 each. The PVC connector was cut down by about 1/4", and a slot for the "E" clip was cut into the threaded rod using a Dremel tool and a cut-off disc. Note that as assembled, the weight of the machine is carried by the "E" clip. So far, it hasn't shown any tendency to break or slip out of the groove (which I couldn't make with perfectly square sides), but I would recommend leaving enough thread below the "E" clip so that the threaded rod bears against the PVC plug. The Tee nuts required a 1 1/4" counterbore in the 2x4 blocks.
To assemble the jack screws, the Tee nut is hammered into the bottom of the counterbore, the threaded rod is threaded through the Tee nut far enough to allow the PVC pipe ring to be slipped over the end and secured with the "E" clip. The PVC ring is then glued into the PVC connector using PVC cement. Finally the PVC plug is screwed tightly into the PVC connector, and the rubber pad is glued to the top of the plug (forming the bottom of the jack screw) with either Gorilla Glue, epoxy or contact cement.
Here the completed jackscrews are mounted onto the mobile base frame. I could have put the jack screws directly into the frame, but to clear the angle iron and assembly screws, they would have ended up in the center of the back rail. Mounting them into separate 2x4 blocks allows them to be positioned close to the outer corners of the base.
The table saw mounted on the base. Note that if you construct yours to tolerances as close as I did, I recommend loosening the bolts on the table saw legs while you lift the table saw legs into the angle-iron pockets. This allows a little "play" in the legs so they'll slip more easily into the pockets. Re-tighten the leg mounting screws after getting the legs firmly in place. Also, because the base is canted slightly toward the front of the saw when stationary, I raised the front table saw leveling screws by about 1" to allow the table saw top to be approximately level. This picture also shows the lifting and moving lever in place ready for use. If I'd used fixed casters, I could move the saw simply by pulling, pushing and steering with the lever. Because I used swivel casters, when pushing I need to guide the saw with my left hand, while lifting, steering and pushing with the lever. Takes a little coordination, but not too bad, and it allows me to get the saw easily into the tight corner where I store it.
Detail of the lifting and moving lever. Just a chunk of 2x4, two fixed 2" hard-rubber casters (JL Industrial #FLT-25783C - $2.40 ea.), a 3/8" screw-hook and a heavy -duty broom handle. Use a 1" forstner bit and drill press to bore a hole for the broom handle, and trim the broom handle if necessary with a spokeshave or block plane. Secure it with Titebond glue and a 1" drywall screw through the back of the block. The "U" bolt is 3/8". Make sure the "legs" are long enough. This one is actually too short, so I wasn't able to secure it with nuts and washers on both sides of the base rail. By the way, I can't claim any credit for this design element. Jamey Amrine, SEMIWW member, showed me the 2x4 and plywood mobile base that sat under the drill press that he inherited from his grandfather. It used this broom-handle, caster and screw hook approach.
The table saw, snugly ensconced in it's parking spot on the new base. Note the cleanout plugs on the floor. Plan ahead! I discovered (too late) that my 1" clearance wasn't sufficient to clear this #*@(#$ cleanout plug which extended about 1 5/8" above the floor. This picture places the right-front leg strategically to hide the notch I had to cut with a sawzall and a shoulder plane to allow me to get the saw back into it's storage nook!! <grrr....>
Careful design pays off! If you design and assemble it right, the machine-moving lever sits neatly on its nose, eliminating the need to hang it from something or otherwise find some way to keep it from falling over and being a nuisance rattling around the shop floor when not in use. And if you think that I actually intended it to come out this way, rather than just being dumb lucky, I have this bridge...