This simple box is an easy way to get into slot and tab design. This method of designing will allow you to create complex assemblies that snap together with no more than glue. This tutorial shows you how to get started with this design method, and shares some tips and tricks we have learned along the way.

Requirements

• 12″ × 12″ × 3/8″ Material (we used Baltic Birch)
• #201 Cutter (1/4″ square endmill)
• Glue
• Sandpaper
• Finish of your choice (we used stain and a clear coat)

Carbide Create File: Download Here

Community Discussion: http://community.carbide3d.com/t/simple-first-project/

Job Notes

• Origin is Lower Left Corner
• Z-Zero is top of material
• Material is 3/8″ thick
• Run time is approximately 8 minutes

Design

This design was done in Carbide Create utilizing the built in corner treatments to create T-bone overcuts. Tabs were used to keep the parts connected to the stock material until cutting was finished.

If you haven’t downloaded the program yet or do not know if you have the latest version, head over to the download page and grab a copy for yourself.

Carbide Create is a cross platform CAD/CAM program that is free to use and highly compatible with most CNC machines on the market.

Get Carbide Create here

Details

After the job finishes, we find it easier to sand the pieces while they are still connected to the nest. Using a Random Orbit sander and 120&ndsash;220grit sandpaper does a nice job smoothing out the surface. Depending on the quility of finish and what material you are using, you may find more or less sanding to be appropriate.

Construction Tabs

Construction tabs are a gift and a curse. They are very effective in keeping your parts connected to the stock material during cutting — the downside is they must be removed, and getting a tab flush with the rest of the face can be a little tricky.

We like to use a couple different methods, depending on the situation. Either a small pull saw, or a multi-tool works well in removing the tabs flush with the rest of the face.

If you find that your tabs are still proud from the face, hitting them with a disc sander is a good way to knock them back down quickly.

Assembly

With the parts removed from the nest, and everything sanded, you will need to wipe down the parts (we used mineral spirits) to remove all of the dust/debris left over from cutting and sanding. After that is finished, you can assemble the box with glue and wood clamps. Make sure to get glue on both mating faces and apply a liberal amount of even pressure to all the faces of the box.

Finishing

After the glue has set, and your clamps are removed, you can finish up the box the way you want it to look. One way to get ultra smooth edges, is to use a belt sander (or large disc sander) and run over each face of the box. This will sand the tabs flush with the sides and create a really sharp looking finish. Be sure to step down with the sandpaper grits on a R/O sander if you’re using a coarse grit on the belt sander!

Design considerations

Follow these 5 simple rules when designing your own slot and tab assemblies.

1. Tab width should be equal to material thickness + 0.010″ (or more)
2. Inside slot width should be equal to material thickness
3. Outside slot width should be equal to material thickness + 0.010″ (or more)
4. Tabs should not be closer than 2× Cutter diameter to any edge
5. All inside corners need to be overcut