Introduction: Multi-Functional Portable Workbench
I am in need for a portable workbench, and it's in my mind for a long time. I went through the sawhorse design and made a couple of them already. Now it’s time to make the table top and put the workbench together.
Step 1: Design Concept
I've done a two-month-long study on the portable workbench, having a bench fever (my wife said) and accumulated a stack of papers full of my brainstorm ideas.
First of all, I’d really appreciated for the people out there on the internets who posted their ideas of making workbenches and tables, I did get many inspirations from all of you, I took some ideas with my own modification based on what I needed for the workbench. Ron Paulk (Google his name you will find his "ultimate protable workbench") has a great workbench, you will see a few of his design elements in my bench because I liked his so much.
In my case, the workbench has to have a large working surface, but portable enough to fit into my minivan, along with my other tools. I was thinking about a 4’x8’ bench but settled with 4’x7’, because it’s easier for my van.
- I like to have two torsion boxes because they are more stable and strong, but they take too much space, so I settled with two of the L-shape half boxes.
- I deliberately designed my bench as a split top with a 12” gap in the middle, easier for breaking up full sheet of plywood with circular saw without sacrificial strips underneath and worry about cut into the bench top.
- I wanted to have two or three different work surfaces for different application, 37 3/4” for the table saw outfeed, cutting plywood and some layout work; 36” for router work, 30” for assembly, cutting narrower strip of plywood, or hand cutting where I can apply some body weight to work piece. I also have a shelf that is 13” off the ground that I can do some painting or assemble taller pieces.
Step 2: Materials
I got a full sheet of ¾” BC plywood from HD. It’s a miss-cut piece that was 23 ½” x 8’ and 24 3/8” x 8’, and discounted in price. I ripped each of them into two pieces: 18” and 5” wide, that would be my table top. I have some left over plywood to make up the rest. They were then cut at 84” long.
Step 3: Folding Sawhorses
There are some more to be done on the sawhorses in order to make this work. See my other instructables for the sawhorse design.
The legs of the sawhorses needed to have some slots for the stretchers (also as shelving supports) to go through. Router with edge guide was used to cut these at the layout lines. Since the load on the sawhorses will increase, stretcher should be made as part of the sawhorses structure to add rigidity of the sawhorses, and yet still removable. Two stretchers were 3"x80"x1/2" plywood, I used 1/2" router bit to cut the slots on the sawhorse legs, and a file to enlarge the slots just enough to let stretcher go through easily, but still have friction between them.
Two pictures showed my prototype idea of locking them together, inside end was a plywood piece cut 15° miter to match the angle of the leg, glued and nailed. The other end was a short piece of cloth hanger bended to an eyehook pin shape, dropped into a vertically drilled hole on the stretcher. If in case I lost the pin(s), no big deal, just make another one or use a nail.
Step 4: Table Top
The bench top was time consuming. Holes were predrilled before the assembly. In case you don’t know why I drill the holes on the bench top, they were there so you can clamp something anywhere on the surface. Festool, Makita and DeWalt all make these special clamps.
Again, layout holes in one piece and transfer the location to the other. They were ¾” diameter and 4” apart on center. Drill press was used for narrower pieces and most of the wider pieces (make sure to have the proper in/out feed support to your drill press). It's good idea to pre drill pilot holes, then complete the final size from both side, or have a backer piece of board under the work piece to avoid tearout. I tried to have some different hole layout for two tops, just consider different clamping situation, and round over after for the finished look.
Narrower piece and wider piece were then glued and pocket hole together using clamps and a square to ensure the right angle. I put two re-enforcement pieces at the ends, I didn’t think they were necessary, but they made me feel better.
Step 5: Shelving Configuration
Bottom shelf was two pieces of ½” plywood cut to dimension. I did have it as one sheet to begin with, but thinking about the portability, I cut it into two pieces. I will add some locating features relative to stretchers and a couple of holes as grip handles later on, and then hinge them together as an easy-fold-one-handed-handling shelf...
Step 6: Finishing
Here is the workbench finished. I used 100 grid sand paper to go over every thing so there wasn't any sharp edge or corner. One coat of shop made wipe-on poly ( 1 part of linseed oil, 1 part of poly and 1 part of mineral spirits) to seal the benchtop (on all surfaces). The thought was that I don't have a boxed bench top, so there is more chance for the bench top to warp over time due to the moisture change. One or two coat of finish will help.
Step 7: Multi-Functional Set Up
First picture was setup for 37 ¾” table saw outfeed and other general use.
Second picture was setup for 37 ¾” split top, the 12” wide strip of plywood was sitting on the right top there. The gap enabled me to cut full sheet of plywood with circular saw without cutting into the top surface, and also have support at both side of the cut line.
Third picture was setup for 30” without extension. I can cut smaller strip of plywood with circular saw, and have support at both side of the cut line. Just move two top pieces apart a bit when necessary.
The fourth picture was 36” work surface for routing. The two half boxes would be clamped together.
The fifth picture was the set up for cross cut narrow board. In order to do this operation, small pieces of strip wood should be glued on the vertical portion of the top as sacrificial pieces, and replace them when needed.
For vertical clamping situation, use the holes on the narrower piece for clamping, set work piece top surface flush with bench top for horizontal support.
I added a couple of pictures to layout some basic dimension for the assembly.
Step 8: Final Thought
The portable workbench works well in my situation. It will fit into my minivan along with other tools without taking a lot of space - check out the first picture; assembly or dis-assembly process takes about 5 minutes, change over from one height to another takes about a minute; Second picture showed the dis-assembled bench in the garage.
With two stretchers, the workbench is very stable, even in a case where a couple of sawhorse legs were off the ground on a not quite level terrain. This is my first prototype workbench, I expect to have a lot of improvement to be made over the next year during the usage, I will update this as I go.
I think the workbench can be simplified to achieve a two heights table by not having the extensions and build a pair of higher sawhorses to your need; or better yet, make the narrower piece at different height, flip both of them up-side-down as the supporting spacers for another sheet of plywood on the top to achieve the third height you need... I believe I created a monster workbench that I just haven't had it long enough to figure out the full potential yet, hopefully you will have a chance to build one for your application and get a full use out of it. Please let me know if you do.
I am planning on the following in the next few weeks.
·Glue some strips of drawer lining on top edge the sawhorses and extensions, so it will grip better. After all that drilling, I don’t want to drill any more locating holes or slots on the bench top anymore… BUT
·I have to route out a couple of holes as grip handles for the bench top. I found they were very awkward to move, not because of the weight but the shape.
·I will have to figure out an easy way to tie two half top pieces together better, clamps sticking out too much.
It’s not the intention to claim that this workbench is the best nor it’s my only design, I HAVE NOT TEST IT WITH EXCESSIVE LOAD TO VALIDATE THE LOADING CAPABILITY. Meanwhile, this is a way to make a workbench to fit my need, also provide some ideas for you to modify to your need. If somehow there’s a design details that has been seeing somewhere else before, that means either the design was inspired by (and should be credited to the other fellow designer's creative mind), which is really appreciated, or all good engineers happened to follow the same physics & design principle.
Finally, as Norm Abrams always said: when you work with power tools, please make sure to read, understand and follow all the safety rules that comes with your power tools, be safe and wood working will be fun.