DIY Heat-Set Threaded Insert Press for 3D Printed Parts

Hello and welcome!

In this project I will show you how to build a DIY hot threaded insert press for 3D printed parts.

This tool is extremely useful for anyone working with 3D printing who wants strong, precise, and long-lasting assemblies.

I decided to build this press for two main reasons.

First, in my previous projects, screwing directly into plastic caused the threads to wear out over time, leading to loose or failed assemblies.

Second, I had many spare parts from an old 3D printer that were no longer compatible with my new Bambu Lab printer, so instead of throwing them away, I reused them for this project.

From now on, every project that requires screws will use threaded inserts. The durability improvement compared to screwing directly into plastic is enormous—almost infinite.

Below is the complete list of materials used to build the DIY Hot Threaded Insert Press for 3D Printed Parts.

Most components are standard 3D printer parts and easy to find online.

1. 20x40 Aluminum Profile – Length 300 mm LINK
2. Soldering Iron (basic model recommended) LINK
3. Threaded Insert Tip Kit for Soldering Iron LINK
4. M2 Threaded Inserts (M2x3x3.2) LINK
5. M3 Threaded Inserts (M3x3x3.2) LINK
6. 2GT Pulleys – 3 mm Bore (2 pcs) LINK
7. 2GT Timing Belt – 500 mm Length, 6 mm Width LINK
8. Screws and Brackets for Aluminum Profile LINK
9. V-Slot Wheel Carriages (2 pcs) LINK
10. Wheel Balancing Weights (2 pcs) LINK
11. Assorted Threaded Insert Kit (M2–M5) LINK
12. M3x16 Flat Head Screws LINK
13. M3x30 Flat Head Screws LINK
14. M3 Screw Assortment Kit LINK
15. M2 Screw Assortment Kit LINK

3D PRINTIG FILE LINK

The first step is preparing the soldering iron.

Remove the standard tip and install the threaded insert adapter. This accessory keeps the insert perfectly perpendicular and improves heat transfer, preventing damage to the soldering tip.

For small inserts like M2 and M3, I used temperatures between 200°C and 300°C, adjusting based on insert size and plastic type.

Installing threaded inserts is one of the most critical steps.

Each printed part is designed for specific insert sizes (M2 or M3), which are slowly pressed in using the soldering iron until fully seated.

Key points:

1. Keep the soldering iron perfectly straight
2. Do not force the insert
3. Allow the plastic to cool before continuing

This method ensures perfect alignment and maximum strength.

Once all threaded inserts have been installed, we can move on to the mechanical assembly of the press.

At this stage, the focus is mainly on the moving carriages and the components that ensure smooth, play-free motion.

The carriages are assembled using V-Slot wheels, placing the standard wheels on the outer positions and the eccentric wheel in the center. The eccentric wheel is crucial, as it allows fine adjustment to remove any unwanted play while maintaining smooth movement.

Next, the pulleys are installed, and the soldering iron holder is fixed to the front carriage. All components must be solid and properly aligned, as the overall precision of the press depends on this step.

Once the carriages are assembled, we can proceed with mounting the aluminum profile structure and the belt drive, which are essential for the press operation.

The 20x40 V-Slot aluminum profile is inserted into the 3D-printed base and secured using self-tapping screws. The carriages are then slid onto the profile, ensuring smooth motion and adjusting the eccentric wheels if needed.

Next comes the belt installation. The belt is routed around the pulleys and secured to the carriages using the 3D-printed belt clamp. It is important to measure the belt length correctly: when one carriage is fully down, the other should be fully up.

Proper belt tensioning is crucial to ensure synchronized, smooth, and precise movement between the two carriages, preventing jerky motion or misalignment during operation.

Once the structure, carriages, and belt drive are fully assembled, we can proceed with installing the soldering iron, which is the core working element of the press.

First, replace the standard soldering tip with the hot threaded insert tip. This accessory is essential as it ensures proper heat transfer and, most importantly, keeps the insert perfectly perpendicular during insertion.

Before fixing the soldering iron to its holder, it is recommended to remove any rubber or silicone grip from the handle. This allows the 3D-printed clamp to grip the rigid body of the soldering iron directly, resulting in a more secure and stable mounting.

The soldering iron is then placed into the holder with the tip facing downward and secured using the printed clamp and screws. Make sure the soldering iron is well-centered and cannot rotate or shift during operation.

Once installed, the soldering iron should move only vertically together with the carriage, without any lateral play, ensuring precision and safety when inserting threaded inserts.

To make the press comfortable and controlled, I balanced the system using wheel balancing weights.

These weights allow you to adjust the soldering iron return speed:

1. More weight → faster return
2. Less weight → slower return

This allows the press to be customized for different working styles.

For the final test, I used M3 inserts of different lengths.

After insertion, I screwed in a bolt to check alignment: the result was perfect, with completely straight screws.

This confirms the effectiveness and precision of the press.

This hot threaded insert press has become an essential tool in my workshop.

It is robust, precise, and delivers professional results on any 3D printed project.

I hope this project was useful and inspires you to build your own!

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