Upcycled Candy Jar Coffee Pot Adapter (with OpenSCAD sources)

Upcycled Candy Jar Coffee Pot Adapter

This is a 3D-printable adapter that turns a glass candy spread jar into a small coffee pot / coffee cup with a handle.

The adapter does not seal the jar and is not a lid. It only provides a handle and a supporting ring around the glass body.

The model was designed specifically for the glass jar from M&M’s Spread with Crispy Pieces. Other similar glass jars may work, but I have only tested this one, and the fit is intended for this exact jar shape.

I printed this adapter in PETG more than half a year ago and have been using it almost daily since then. I use it with my coffee machine to collect freshly brewed coffee and then pour it into another cup or container.

What it does

The adapter adds a screw-in handle to the glass jar. It consists of two printed parts:

1. A clamp ring / hoop that fits around the glass jar

2. A screw-in handle that attaches to the ring

The result is a small reusable coffee pot made from an upcycled glass candy jar instead of throwing the jar away.

Important fit note

The original jar is not a perfect straight cylinder. It is slightly wider at the top than at the bottom.

Because of this, both the adapter ring and the handle orientation matter. The adapter should be installed from the bottom of the jar upwards. Do not force it too hard; it should fit firmly, but excessive force may damage the print or the glass.

The handle also fits correctly only in one orientation because the jar shape is tapered.

Preparing the jar

Before installing the adapter:

1. Empty the jar completely.

2. Wash it thoroughly.

3. Remove the label.

4. Clean off any remaining glue from the label.

5. Let the glass dry completely.

6. Slide the printed adapter ring onto the jar from the bottom upwards.

7. Screw the handle into the ring.

Recommended material

I recommend printing the adapter in PETG.

PETG has worked well for me in daily use. I have not tested PLA for long-term use with hot coffee, and I would not recommend it as the first choice due to the heat involved.

OpenSCAD source

The model was created in OpenSCAD, and the source code is included.

To run the OpenSCAD file correctly, you need the threadlib library installed, since the handle uses a printed screw thread.

Main design parameters

// glass jar/cup:
cup_h_mm = 84;
cup_diam_low_mm = 67;
cup_diam_high_mm = 74;
plastic_hoop_h_mm = 25;
plastic_hoop_thickness_mm = 5;
// Handle:
handle_length_mm = 100;
handle_diameter_mm = 24;

These dimensions were chosen for the M&M’s Spread with Crispy Pieces glass jar.

Optional coaster / bottom protection

If you plan to use this jar directly under a coffee machine, especially on a metal drip tray or metal base, I recommend printing a separate small coaster or bottom protector.

For my own use, I made a simple TPU-95A coaster:

• Diameter: 67 mm

• Thickness: 2 mm

• Material: TPU-95A

This helps protect the glass bottom and makes the setup feel more stable when placed on a hard metal surface.

Safety notes

This is a DIY upcycling project, not a certified food-safe commercial product.

Use common sense:

• Do not expose the printed adapter to open flame.

• Do not put the printed parts in a dishwasher unless you know your filament can handle it.

• Do not overtighten or force the adapter onto the glass.

• Check the print regularly for cracks, deformation, or loose fit.

• Be careful with hot coffee and glass.

The printed adapter does not contact the coffee directly in normal use, but the glass jar obviously does. Make sure the jar is properly cleaned before using it.

Feedback

If you print this model, I would be very interested to see how it works for you.

Please share your print, your material choice, and whether you used the same M&M’s Spread jar or adapted the design for another glass container.