How To Make An Assembly Table Workshop Projects
I got a CNC from STEPCRAFT and it came in this large crate:
And while unpacking it, I noticed that the plywood they used to build the crate was an order of magnitude better than the stuff I’d seen before. Usually if a crate has plywood, it’s of such terrible quality that you really can’t use it for anything. So I thought it would be interesting to use a lot of that plywood to build the table the CNC would be set up on.
First, I had to select and clear an area in my small shop that’s big enough. I want the CNC to be ready to use at all times, so making something that folds up wouldn’t work. Likewise mounting it vertically on the wall would limit the size of the parts I could operate on; for example to mill a craving into a long board for a bed rail. I know, that’s probably a very rare event, but I think the best overall way is to make this as convenient as possible to use. And then I will probably use it!
Since the CNC was inside the crate and already assembled, I knew the top and bottom of the box was more than big enough to make the top for the table. I cut the top layer of plywood 37″ x 50″ and figured it would be neat to leave the stenciled logo visible:
The top is a torsion box – a thinner skin top and bottom with a ribbed structure inside. This results in a very strong, flat and lightweight top that resists bending. It also uses up a lot of scrap plywood:
I did the top assembly on my workbench with a sheet of 3/4″ Baltic birch plywood laid on top to provide maximum support while gluing the torsion box. To have a flat top, it needs to be assembled that way – perfectly flat. Otherwise, if there’s a twist in your work surface, that will be transferred permanently to the torsion box. So having a dead flat workbench to begin with puts you ahead of the game.
I cut the plywood for the bottom slightly oversized and will cut off the excess after the glue dries with a flush trim bit in my router.
The legs are made from recycled (from an old project that didn’t work out) 1/2″ fir plywood. Cut into strips to fasten together into an “L” shape.
They then get screwed directly to the edge of the torsion box top at each corner:
This leg construction method is simple, easy to do and very strong. And removable, if I need to take the table apart:
I figured the best way to add storage was to make a pair if medium depth drawers under the top. These can hold the accessories needed for the machine, and leave the rest of the underside of the table open to add anything else that’s needed. I know from experience that a big shelf would just end up collecting a pile of junk. So before I make a shelf, I want to know exactly what will be going on it and then I can make it just big enough for that.
The drawers are simple as well – just butt joined with more of the 1/4″ plywood from the crate dadoed into the sides, front and back for the bottom:
I added rails on each end and divider in the middle to mount the slides:
Also thought it would be good to have a panel that can slide out to cover the drawer that can be used as a work surface. For example, a laptop computer will run the CNC, so it can be taken out of the drawer and set on the slide out panel to use.
I used more of the crate plywood and just added narrow cleats (more plywood) to guide the panels:
With all of that done I could carefully move it down to the floor:
And start working on another interesting feature of this table: the independent rear suspension. That stiff, flat torsion box may prevent all of the wheels from sitting firmly on the floor if the floor isn’t perfectly flat. Mine definitely isn’t, so this mechanism is designed to cope with that problem.
Basically, it converts the two back casters into one but mounting them on a “seesaw” that pivots in the middle. First step is to fasten the casters to a strip of plywood:
Then I made long brackets from 1/2″ plywood and drilled a 2″ pivot hole for the axle:
I drilled holes through the stretchers (I added another one on the inside) that the axle will go through:
And made wooden springs that provide some downward pressure over the wheels. This may or may not have necessary, but it can’t hurt:
With the wheel “carriage” installed, it can rock slightly from side to side and conform to an uneven floor:
And with the panels extended:
With the CNC on and parked where it will be:
Mobile to be able to pull it out into the room if needed:
I added the drawer fronts and painted those and the legs. Now all I need to do is figure out how the CNC works…
The build video: