CNC Coffee Clip + Scoop

This was an afternoon project I made out of need for my own coffee bag clip, since then I have started to also sell these occasionally on Etsy!

Made from solid off-cuts of Maple, these clips have a 3mm slot which effectively holds a coffee bag shut when the top is folded over a few times.

The scoop has been designed to hold around 5g of ground coffee making it ideal for dosing as well!

Step 1: Inspiration

This is not a new concept but they either tend to be metal with a spring clip or wood with a higher price!

I decided to design my own purely because I was in between projects at the time and wanted to use up some of my off-cuts of maple from past projects! It should be a fun little project and can probably even be done without a CNC. The scoop could be drilled with a forstner bit and the shape cut with a bandsaw or scroll saw!

Step 2: Design

When I first started to design this, the piece of wood I was using to visualize the clip was 15mm thick and so this dictated the rest of the dimensions.

With wooden items, I like to have a minimum floor thickness of 3mm for pocketed areas. So the max depth for the scoop portion of the clip would be 12mm. Therefore, with a scoop area of around 1200mm^2, the volume of the scoop would be approximately 14000 cubic mm (14cm^3).

According to vCalc, ground coffee has a density of 0.365g/cm^3, which means that a level scoop of coffee would be about 5grams. This is typically how much coffee I use (per cup) when brewing with a cafetiere so this is ideal!

As this part was going to be made with my CNC, I designed the slot to clip onto the coffee bag to be just over 3mm as this is the smallest bit I have that can cut to a depth of 15mm.

Step 3: Making

Jumping into the CAM; I first defined the stock around the part and began to apply toolpaths to machine the shame from the stock.

I used a 3mm endmill on my shapeoko 3 CNC router to cut the whole part out and be small enough to make the slot fairly thin.

An adaptive strategy was used for the scoop and then the wall finished with a contour tool path. Finally, a contour tool path with 1mm stepdowns was used to cut the perimeter of the part.

Edit: I have added an STL if you would like to print this out on your own printer! I would recommend using PETG for durability :)

Step 4: Finished!

And that's all there was too this little project, just some final sanding and a food safe finish (I use Osmo oil) and it went straight into use on my current open bag of coffee!

A simple project but something that will get a lot of use for many years to come!