I along with The Makers of Things setup a makerspace in Riverside school, I designed a set of low tables and some storage units for keeping powered tools and material.

We also wanted to show kids the sort of things you can create with a CNC mill (Shopbot PRS Alpha) and the different types of joineries and assemblies which can be achieved. When using high tables it becomes difficult to keep all the things around. The idea behind making the low tables was to provide kids with extra space around them while they sit on the floor and do their activities. These tables are really easy to assemble and can be put together in matter of minutes.

The tables were painted and then permanently fixed as there was no need for them to be taken apart.

CNC Routers have become affordable in the last couple of years and there are quite a lot of DIY CNC Routers out there. If you have a Fablab close by you can probably make it over there.

I took references from alepalan instructable.

Step 1: Materials and Tools

List of Materials

Rubberwood 12mm (3feet x 3feet)
MDF 18mm (4feet x 4feet)
Screws
Sandpaper
Oil Paint
Plastic Foot pegs
Wood Polish

List of Tools

CNC Milling Machine (I used a Shopbot)
Sander/Files
Mallet
Cordless Drill Machine
¼ inch 2 Flute End Mill

In case you don't have a sander, just use a file or sandpaper.

You can use a 1/8 inch End Mill if you want higher finish.

IMPORTANT: measure the thickness of your plywood.This is really important to take note because the design has locking parts and we need to accommodate for a thicker material. The slots which I've made are according to 18mm thickness. You can modify the CAD Files according to your material thickness.

Step 2: Design and CAD File Generation

I used Rhino to design the table as I'm familiar with it. You can edit the files as you wish and make your own version .

I actually milled 3 table top out of one 8'x4' rubberwood sheet. The Rhino and Autocad file I'm attaching is for a single table. You can download the Rhino file and to play around and edit the design.

Once I had all the flat pieces, I arranged them in 8’ x 4’ sheet. Download the Autocad(dwg) file that you will need to create the toolpaths. I gave dogbones to the pockets in VCarve as it's easier in that.

The red paths in the Table Top file is for making through pockets.

Step 3: Creating Toolpaths for Table Top: VCarve

Table Top VCarve File

Create a New File.

Now in Job Setup: We will create a file with the size of our Table top 3' x 3' x t (t = Thickness of your true material). In my case it was 12mm. Zero on the top.

Import Vectors files and your vectors will appear on your sheet. Sometimes your vectors might be outside the sheet so will need to zoom out.

Another thing you need to do is actually joining open vectors, under the section Edit Vectors. Control+A will select all of the vectors and then hit the Join button. Hit the Join button again.

If you need to correct or move some objects around the sheet now is the time to do it. You might want to do this to optimize material. Control + A (select all), click on the right tab: Toolpaths (pin it so you have it open for the rest of your session).

T Bone: Use the T Bone button to create T Bones on the Slots.

PROFILE TOOLPATH For Slot: Click Create Profile Toolpath. The first set of values will determine how deep you want to make the cut. Our start depth will be zero since we zeroed on the top of the surface. You want to cut all the material and a tiny bit of the sacrificial board so add a little depth to your Cut Depth (C).

Now you need to select the Toolbit you will be cutting with. Click on Select and use a 1/4 inch End Mill.

Since we are cutting the pieces mark on Machine Vectors: Inside.

Add Ramps to Toolpath, Smooth, pick a Distance (4-6 inches works well).

Save Toolpaths: You will be prompted a "WARNING - Tool will cut through material" but you know that already because you did that on purpose when you selected the cutting depth. Once you succesfully created the toolpaths you will see a preview. Once you are satisfied with what you see, hit Close.

Make sure you select Profile 1 and hit Save Toolpaths, it will have an extension SBP.

PROFILE TOOLPATH For Table Outline: Click Create Profile Toolpath. The first set of values will determine how deep you want to make the cut. Our start depth will be zero since we zeroed on the top of the surface. You want to cut all the material and a tiny bit of the sacrificial board so add a little depth to your Cut Depth (C).

Now you need to select the Toolbit you will be cutting with. Click on Select and use a 1/4 inch End Mill.

Since we are cutting the pieces mark on Machine Vectors: Outside.

Add Ramps to Toolpath, Smooth, pick a Distance (4-6 inches works well).

Add Tabs.

Save Toolpaths: You will be prompted a "WARNING - Tool will cut through material" but you know that already because you did that on purpose when you selected the cutting depth. Once you succesfully created the toolpaths you will see a preview. Once you are satisfied with what you see, hit Close.

Make sure you select Profile 2 and hit Save Toolpaths, it will have an extension SBP.

NOTE ON CREATING TABS: Tabs are pieces of your material that won't be cut to hold the parts in place. For this Profile 1 I didn't give any tabs for Profile 2 I gave 4 tabs of 8mm length and 4mm thickness.

Step 4: Zero X, Y and Z Axis

Now you are ready to cut the pieces for your table. Place your 3’ x 3’ sheet of 12mm rubberwood on the worktable of the Shopbot. Use screws/clamps to get the sheet down to the table.

Turn on the Shopbot and the Computer. Open the Shopbot manager. Put the ¼ inch End Mill on the Collet and you are ready to Zero the machine in 3 axis.

Use the proxy switches to Zero both X and Y Axis. Now use the Z plate to zero the Z axis of the Machine. Zero Z Axis with Z Plate: Cuts - C2: Zero Z Axis w/Zero Plate.

It will prompt if we have the Zero Plate below our bit. Hit Enter when ready.It will now go down, touch the plate, go up and then slowly go down again to touch the plate one more time.It will prompt that it has been zeroed.

Step 5: Run Toolpath File for Table Top

If you are using the Shopbot for the first time in the day then perform the Spindle Warm up or by using C3 command.

We are first going to mill the slots out. Open your Profile 1 Toolpath file and hit Start. You will be prompted a Warning message to start your Router/Spindle. Make sure you actually start the spindle before hitting OK on the Warning message.

The Shopbot will now begin to make the cuts on your material.

After milling the slot we'll mill the table outline. Open your Profile 2 Toolpath file and hit Start. You will be prompted a Warning message to start your Router/Spindle. Make sure you actually start the spindle before hitting OK on the Warning message.

We milled the pockets first as the board will be properly clamped.

Step 6: Watch and Remove Parts

Now this is the easy and fun part. You sit down next to the router and watch how the machine cuts all of your pieces. Since I was using a ¼ inch End Mill it will make 3 passes before it actually cuts loose each single part. It will start by doing the slots and then the profile cut.

Remember that we didn’t add tabs so if your pieces are really close to each other it might be a good thing to take your recently cut piece out of the table. I did this easily without stopping the machine.

I had to vacuum the chips which were being generated.

Once the job is done the Spindle will turn off automatically and you can unscrew your material off the worktable.

Step 7: Creating Toolpaths for Table Legs and Support: VCarve

Table Legs and Support VCarve File

Create a New File.
Now in Job Setup: We will create a file with the size of our Table Legs 3' x 3' x t (t = Thickness of your true material) In my case it was 18mm. Zero on the top.

Import Vectors files and your vectors will appear on your sheet. Sometimes your vectors might be outside the sheet so will need to zoom out.

Another thing you need to do is actually joining open vectors, under the section Edit Vectors. Control+A will select all of the vectors and then hit the Join button. Hit the Join button again.

If you need to correct or move some objects around the sheet now is the time to do it. You might want to do this to optimize material. Control + A (select all), click on the right tab: Toolpaths (pin it so you have it open for the rest of your session).

T Bones: Use the T Bone button to create T Bones on the Slots.

PROFILE TOOLPATH: TClick Create Profile Toolpath. The first set of values will determine how deep you want to make the cut. Our start depth will be zero since we zeroed on the top of the surface. You want to cut all the material and a tiny bit of the sacrificial board so add a little depth to your Cut Depth (C).

Now you need to select the Toolbit you will be cutting with. Click on Select and use a 1/4 inch End Mill.

Since we are cutting the pieces mark on Machine Vectors: Outside.

Add Ramps to Toolpath, Smooth, pick a Distance (4-6 inches works well).

Save Toolpaths: You will be prompted a "WARNING - Tool will cut through material" but you know that already because you did that on purpose when you selected the cutting depth. Once you succesfully created the toolpaths you will see a preview. Once you are satisfied with what you see, hit Close.

Make sure you select Profile1 and hit Save Toolpaths, it will have an extension SBP.

NOTE ON CREATING TABS: Tabs are pieces of your material that won't be cut to hold the parts in place. For this Profile cut I didn't use Tabs as they were not required and the amount to be cut was really small.

Step 8: Repeat the Run Toolpath File for Legs

Repeat Step 4, Step 5 and Step 6 for the Table Legs file as the thickness of MDF sheet is different from rubberwood.

Step 9: Minor Adjustments

I found out that my pockets were a bit tight for my joint so I had to sand the MDF legs and the slots in the rubberwood. I did this by using a sander on the MDF legs and support. I used a file to widen the slots in the rubberwood top.

I sanded down all the edges of the top, legs and support to give it a nice finish.

Step 10: Assemble Legs

Now it is time to assemle the pieces together. I started by joining the two legs.

Then I put the two supports in the slots made for them. Then using a cordless drill I drilled a hole in through the support into the leg. Then using a screwdriver I drove a screw into support and the leg.

Step 11: Paint Legs and Add Footpegs

After the legs were assembled, I applied wood primer on the legs and support and kept them to dry for almost 8 hours.

After the primer was dry I applied a layer of oil based paint. I left the legs to dry for 8 hours. And after it dried I applied another layer of oil paint.

After the paint on the legs dried I put 4 plastic footpeg on the four legs using a screwdriver.

Step 12: Apply Wood Polish

Apply wood polish to all the surfaces of the table top and let it dry for at least 6 hours.

Step 13: Assemble the Table Top

Once the table top is dry, align it's top slots with the fingers on the legs. Use a mallet to put it in place. After it sits in the fingers add 4 screws from the top into the legs.