Recycle Filament Scrap into Spool Weights

♻️ Recycle Filament Scrap into Spool Weights

Turn filament waste into something useful.

This compression mold allows you to recycle purge lines, failed prints, supports, and filament offcuts into solid reusable inserts. Instead of throwing filament waste away, it can be reheated and compressed into durable pucks.

These inserts were designed to work alongside my AMS / AMS 2 Pro Spool Weight Screw Case, allowing recycled filament to be used as spool weight inserts instead of coins or batteries.

⚙️ How It Works

Adds weight to lightweight or near-empty filament spools, helping them rotate more smoothly and reducing unwanted unwinding, wobble, and spool movement.

The mold consists of a base and compression plunger.

Filament scraps are placed inside the mold and heated using a heat gun or hair dryer until the material softens. The plunger is then pressed down to compress the softened filament.

Vent holes in the plunger allow trapped air to escape, helping create a denser insert.

When compressing the material, the lip of the plunger eventually contacts the base of the mold. This acts as a built-in stop and automatically forms a puck of the correct thickness for the spool weight holder.

The mold cavity includes a slight taper, which helps the finished insert release easily once cooled. The puck can then be pushed out using the hole in the base.

🔧 How To Use

Before use, please read the safety notes below.

⚠️ Safety Notes

• Use in a well-ventilated area when heating or processing filament scrap
• Avoid inhaling fumes from melted or heated plastics
• Do not overheat filament — excessive heat may release harmful fumes
• Keep away from children during heating or processing
• Use appropriate tools and heat sources responsibly

1️⃣ Collect filament purge lines, supports, failed prints, or scrap filament
2️⃣ Cut the scraps into smaller pieces so they pack into the mold more easily
3️⃣ Fill the mold cavity with filament waste
4️⃣ Heat the material using a heat gun or hair dryer until it softens
5️⃣ Insert the plunger and compress the softened plastic
6️⃣ Continue heating and compressing until the plunger lip reaches the base
7️⃣ Allow the mold to cool completely
8️⃣ Push the finished puck out through the hole in the base

You now have a recycled filament insert ready to use.

🖨️ Print Recommendations

• Material: PETG minimum recommended
• Layer Height: 0.2 mm
• Walls: 4
• Infill: 15% (Which I found to be stable)
• Supports: Not required

PLA is not recommended due to the heating involved when softening filament scraps.

A small amount of oil or release agent can assist with removal, although it is not necessary thanks to the tapered mold design.

📦 Compatible With

Designed to work with my:

AMS / AMS 2 Pro Spool Weight Screw Case

The recycled inserts fit perfectly inside the holder once compressed.

🧠 Extra Uses

Even if you don't use the inserts as spool weights, the finished pucks make unique colourful paperweights thanks to the random patterns created when the filament melts together.

Every puck comes out completely different.

The insert can simply be a small packet filled with filament scraps or purge pieces if you prefer not to melt or mould the material.

🖨️ Printer Compatibility

A Bambu Lab A1 Mini print profile is included, allowing the model to be printed easily on the smaller build plate.

♻️ Enjoyed this project? Check out my Recycle Filament Scrap into Unique Coasters mold. Using the same recycling process, you can transform purge lines, failed prints, and filament offcuts into unique functional coasters. Available in both 80mm and 100mm sizes.

https://makerworld.com/en/models/2914347-recycle-filament-scrap-into-unique-coasters#profileId-3259905

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