Introduction: Mobile Multi-Tool Workstation
I have lots of projects in mind to start in my basement, with plenty of tools. But most of my tools are bench top size and I frequently found the need to support both ends of a cut but never had a reliable solution. So I built this workstation with a height adjustable platform to accommodate the tools I used the most. The top of the workstation supports my circular saw crosscut jig that makes perfect 90 degree cuts (or any other). I made the crosscut jig large enough to cut boards and 2 foot x 4 foot sheet goods. By removing the crosscut jig I can utilize the adjustable platform below for my Bladerunner jigsaw table, my drill press and even my bench top table saw. Now I can cut or drill just about anything and not have to worry about an end dropping off splintering the work or trying to hold one end with my hand while my other hand feeds the tool. I also put the whole thing on wheels too. Some of the photographs may not reflect the instructions exactly, just follow the order of the instructions because that will keep you from making some of the mistakes I did.
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Step 1: Materials
Four 12 foot long 2"x4"s (as straight as possible)
Approximately eight, 8 foot long 2"x4"s
2' x 4' sheet of 3/4" plywood
1 pound 3" deck screws (I used Grabber exterior deck and fence screws with bugle head)
4 casters with bolts and nuts long enough to pass through 2"x4"x12" board
One 3 foot long piece of 2"x12" board
Four 3/4" U-bolts
Two 4" long 1/2" bolts
4 foot 1" steel pipe
Four 2 foot long pieces of 1/2 threaded rod
Twelve 1/2" wing nuts and sixteen 1/2" washers and nuts
drill (and preferably a drill press)
drill bits (including 1/2" and 1" bits)
wood glue or construction adhesive (PL Premium)
pipe clamps or other long clamps
Step 2: Build the 'ladders'
The spacing between the 2"x4"x12's was already determined by the width of the existing crosscut jig. The width also needed to accommodate the 2'x4' Formica covered particle board. The width ended up being about 20" between the 12' rails. The structure is very simple. Two duplicate 'ladders' are needed, using the twelve foot long 2"x4"s as rails with six 20" crossbeams between them. Make sure to space the crossbeams far enough apart that you can accommodate the footprint of the larger tools. I pre-drilled all the screw holes and used soap to make the screws go in easier. Two screws at each end of the crossbeams. I used a pipe clamp to sandwich the crossbeams between the rails while I drove in the screws. I used a small angle bracket as a makeshift drill guide to help me drill perpendicular. Pick your two straightest 2"x4"x12's to use for the top and mark an arrow on each pointing up to the top side of the rails which the panels sit on top of. Make sure that the crossbeams are just a little lower than the top of the rails so that the panels sit flat against the 2"x4"x12's.
Step 3: Build the Wheels
Next build the mobile base because that will determine where you need to drill the axle holes in the four legs. I got a cheap Harbor Freight dolly with four casters for less than the price of one caster at a home improvement store. Plus they came with nuts, bolts and washers that were long enough to go through the 2"x12" board I was using. The exact length of the board is designed to fit between two legs positioned to the inside of the rails, which came out to be about 16 1/2" in my case. The 3/4" U-bolts were not long enough to pass through the board so I drilled out a relief in the bottom so I could attach the nuts. The length of the pipe has to be the length of the board plus long enough to pass through the two 2"x4" legs on either side; plus a little extra if you want to drill the ends through and install a cotter pin. When the U-bolts are cinched down though the pipe will not slip out.
Step 4: Attach the Stop Block Assembly
These pictures show the completed full assembly, but you won't know how long to make the stop block until you've attached the legs in a later step. When the workstation is lifted high enough the stop block will swing down from the lifting beam by gravity and lock the wheels down. The last picture shows the stop block lifted up out of the way with the string allowing the wheel board to fold up and the workstation to rest on its stationary legs.
Step 5: Planning the Axle Holes
4 holes will have to be drilled in 4 legs for the two axles. The hole placements are critical and will depend on the size of your casters, which is why the previous step needs to be completed first. Then you can place the wheel boards next to a leg and mark the spot for the hole. When the workstation is resting on its legs the wheel board should be tilted up like in the picture. I would recommend drilling the hole an inch or two lower than what is seen in the picture. This picture shows the axle hole drilled before adding the stop block assembly, complete that step first before drilling your holes or the lifting beam may be too close to the floor and block the wheel board from rotating upwards.
Step 6: Attach the Legs
I determined the length of the eight legs based on what was comfortable for my height (31"). You can easily customize this height for yourself. The space between the two shelf ladders was about 15 1/2". I would suggest decreasing the space between the shelves by about 3 or 4 inches though because I almost didn't have enough room to fit the lifting beam with the stop block over the wheel board. Prop the bottom shelf up on something and dry fit the axle legs to the bottom rails to ensure you have enough clearance for the wheels to fold upward when the workstation is resting on its legs. Mark the best position for the axle holes and drill each hole through both legs at the same time (they should be slightly over 1" - you can widen a 1" hole with sandpaper or a round file). I used masking tape to hold each pair of legs together while drilling the hole. You will probably have to separate the legs after drilling as deep a hole as you can, then locate the bit over the partial hole in the bottom leg to complete the hole You don't want the wheels unable to fold up because it is hitting the bottom of the lifting beam. Once you have the clearance you need mark the spot where the leg should attach to the bottom rails and transfer that height to all the other legs.
I used pipe clamps to gang the legs together and a carpenter's square to carry that position across to all the other legs. I then drilled 3 holes in each leg for each rail attachment point and applied construction adhesive for rigidity to the joint. Make sure that when you install the legs that there is still sufficient room for the base of the tools to fit through the top opening. The center space in my case was not long enough between the center legs to set the table saw into and I had to move it and the platform to side. Rubbing soap on the screws definitely helped them go in. There is a picture of the workstation on its side with one side of the legs attached. Once you have attached the legs you will be able to determine the exact size of the stop block that you need. Make the length of the stop block from a scrap 2"x4" such that when it swings down to lock the wheels the wheel board should be horizontal. The hole in the stop block should be located towards the top of the block so the block will 'hang' long end down. I attached a string to pull the stop block up and out of the way when the workstation is lifted to allow the workstation to rest on the legs.
Step 7: Build the Elevating Platform
The elevating platform is simply a piece of 3/4" plywood 19 1/2" x 24" for the bench top tools to sit on. It uses four 1/2" threaded rods fixed to the workstation through 1/2" holes in 2"x4"s. Wing nuts and washers lock the 2"x4"s to the bottom rail and raise the platform to make the tool top flush with the support panels. Drill each of the two sets of 2"x4"s together to make sure that the holes are perfectly aligned. The holes in the plywood platform are located over the corresponding 2"x4" holes below it but are drilled 3/4" to allow for a little play. The platform rests on four 1/2" washers supported by wing nuts just below them. By loosening the wing nuts on the very bottom the whole platform can be moved left, right or center on the workstation to allow the length of the work piece to be supported. Be careful to make sure the platform is big enough to support the footprint of the larger tools, in some cases it may be a tight fit.