When it comes to adding durability and strength to 3D printed parts, threaded inserts are a game-changer. They allow for robust screw connections, far surpassing the limitations of threads directly tapped into plastic. But with various types and price points available, choosing the right insert can be challenging. This article provides a 3d Print Compare, examining different threaded inserts to help you make informed decisions for your projects.
Let’s start by comparing costs. Budget-friendly inserts can be found for as low as $3 per 100, translating to a mere 3 cents each. Stepping up in price, Ruthex inserts are priced at €8.99 for 50, making them approximately 18 cents apiece. Inserts with similar designs to more premium options are available at €12.45 for 50, costing around 25 cents each. While the initial cost difference might seem small, it can add up depending on the scale of your 3D printing projects.
Beyond price, the physical characteristics of these inserts vary significantly, impacting their ease of use and performance. The more expensive inserts, like Ruthex and similar premium types, often feature a flange with a chamfer. This design element is a significant advantage during installation, guiding the insert smoothly into place before final insertion. In contrast, cheaper inserts typically lack this feature, making the mounting process more difficult and potentially less precise.
Knurling, the textured pattern on the insert’s exterior, also plays a crucial role in performance. Budget inserts usually feature vertical knurling. While effective for resisting torque-out (rotational forces), this pattern may offer less pull-out resistance (axial forces). Mid-range inserts often incorporate both horizontal and vertical knurling, aiming for a balance of both resistances. Ruthex inserts, on the other hand, boast a sophisticated diagonal and opposing knurling pattern, suggesting enhanced performance in both torque-out and pull-out scenarios.
To evaluate the real-world performance, testing torque-out strength (resistance to rotation) and pull-out resistance (resistance to axial force) is essential. Furthermore, for comparison, it’s useful to consider the traditional method of directly screwing M3 screws into slightly undersized holes in 3D printed parts. This provides a baseline against which the benefits of threaded inserts can be measured.
When using threaded inserts, accurate hole sizing in your 3D prints is critical. Ruthex inserts conveniently include a manual specifying the recommended hole size. However, for other inserts, determining the correct size often involves some guesswork based on their external geometry. As a starting point, 4.0mm holes were used for Ruthex, 4.1mm for eBay inserts, and 4.5mm for injection molding-style inserts in a comparative test setup.
It’s important to understand why achieving precise hole dimensions in 3D printing can be tricky. Printed holes frequently turn out smaller than the intended CAD design. Several factors contribute to this phenomenon. Firstly, material shrinkage occurs as the plastic cools after printing, causing dimensions to contract. Secondly, the triangulation process during STL file generation also plays a role. When a circular hole is triangulated, the triangle points are positioned on the circumference, but the triangles themselves overlap inwards, effectively reducing the inner diameter of the hole. The quality setting during STL export, which dictates the number of triangles, influences the severity of this effect; fewer triangles lead to a more pronounced shrinking effect. To compensate for this, a practical approach is to print test strips with varying hole diameters in small increments (e.g., 0.1mm) and then gauge the effective diameter using drill bits. For example, with Original Prusa printers and Prusament filament, a 0.1mm compensation was found to be necessary, meaning a 4.0mm hole in the print required a 4.1mm design in CAD.
In conclusion, when you 3D print compare threaded inserts, consider not only the initial price but also the features, knurling type, and ease of installation. While cheaper inserts offer a cost-effective solution, mid-range and premium inserts like Ruthex often provide enhanced features and potentially superior performance. Understanding hole size compensation in 3D printing is also crucial for successful insert integration. By carefully evaluating these factors, you can select the most appropriate threaded inserts to ensure strong and reliable connections in your 3D printed projects.
