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如果您曾经设计并且3D打印了需要高维准确性的零件，那么您可能对结果感到失望。也许螺栓不适合3D打印的孔，或者3D打印的支架不适合其预期的凹槽。无论尺寸意图是什么，3D打印零件都可能无法发挥作用，因为3D打印机缺乏按设计制造它的尺寸精度。
这是否意味着您需要更改制造过程？不必要。有时3D打印a part is the right choice, but some features need to be fine tuned with post processing. Using 3D printing as your primary manufacturing process makes sense if you’re producing low to mid-volume quantities or want the flexibility to change your design even when you’re in the midst of making parts.
本文没有完全改变制造过程或设计复杂的，手动的后处理工作流程，而是探讨CNC加工your 3D printed parts. Doing so can improve dimensional accuracy, reduce waste material, and save time and money in your manufacturing operation.
提高尺寸准确性和精度
CNC加工可以比由于3D打印的尺寸精度和精度更高。fundamental differences在两个制造过程之间。如果您在3D打印零件上具有某些功能，需要根据您的规格（高精度）精确地制造，并且/或您需要每次（高精度）的某些功能，那么CNC加工您的3D打印一部分可能是一个不错的选择。
What kind of features on your 3D printed part might require improved accuracy or precision? Here are a few examples:
- Holes.圆形洞穴和圆柱凹处。当然，通常是为了适合或通过它的东西。但是，根据机器和使用的3D打印技术，3D打印的孔通常略有变形或尺寸不准确。
- Edges/extents of your part.Dimensional inaccuracies and lack of precision in 3D printing often make fitting 3D printed parts into assemblies challenging. If your 3D printed part is intended to fit somewhere, particularly in a tight recess, CNC machining the edges to trim it exactly to your specifications could be the key to making the part fit!
- 凹进部分。Similar to edge finishing parts to get a good fit in assemblies, CNC machining in post can create accurate recesses in parts that are needed to provide the fit you’re looking for. This process can be particularly helpful for product design, as products often rely on snap-fits or interference fits to keep unique parts of the product together as a unit.
In order to incorporate CNC machining into your 3D Printing workflow to improve dimensional accuracy and precision, you need to consider a few design points. First, you need to make sure that the CNC mill can reach all desired features and that nothing obstructs the tool path. Also, you need to build excess into the part so that the CNC mill can cut away material to meet the part’s spec. Finally, build in flat surfaces for fixturing if possible — doing so will enable the CNC mill to achieve maximum precision and mitigate potential failures in the manufacturing process.
减少废物材料和整体材料成本
Fully switching from 3D printing to CNC machining for your part would likely drive up the cost of production. A hybrid approach can minimize manufacturing costs while delivering a part that exactly suits your needs.
In general, 3D printing materials cost less than stock for CNC machining, so using 3D printing for the bulk of your part is likely to be significantly cheaper than machining a part from scratch. Furthermore, since 3D printing is an additive method, it produces much less waste material than CNC machining — which lowers material cost and makes for a more sustainable operation. And since lean, sustainable manufacturing operation is the way of the future, using a hybrid approach can be an effective way to stay ahead of the curve!
避免手动后处理
通常，通过手动钻孔，打磨或雕刻零件在3D打印零件中实现尺寸精度，以实现所需的尺寸和拟合。这需要大量时间和对细节的关注，因此昂贵且效率低下。通过完全消除手动后处理，邮政中的CNC加工可以大大减少生产零件所需的时间和金钱。
让我们考虑一个模范案例研究：
- You have a 3D printed part with a dozen 0.25” mounting holes (see images above for reference). 200 parts need to be shipped out within 1 week.
- It takes 1 person 6 minutes to drill out all of the holes on the part so that the fasteners fit properly. To get the parts ready by the end of the week, the person will need to spend 1200 minutes or 20 hours drilling parts to hit the deadline.
- Alternatively, an engineer spends 4 hours of work prepping a CNC machine tool path to drill out the parts. The CNC machine can drill out all holes in 2 minutes, cutting the overall post-processing time from 20 hours to under 7 hours. All in all, the CNC post-processing workflow takes under 11 hours vs. the 20 hour manual post-processing, making for a far quicker and more efficient production process.
Cutting out manual post-processing is a sure-fire way to keep your manufacturing costs low and produce your parts on time every time. CNC machining your 3D printed parts can help you stay true to your timelines while freeing up human resources to do more important tasks!
结论
3D打印和CNC加工是两种截然不同的制造技术，具有截然不同的优势和劣势。但是，如果您一起利用它们，则可以开发一种制造方法，该方法可以提供两者的优势和两者的劣势。混合方法可以以高维的精度，低材料成本/最小废料制造您的零件，而无需艰苦的手动后处理。
Fictiv doesn’t currently offer CNC machining services for 3D printed parts, but our CNC machining services can deliver tolerances as tight as .05mm for other plastic materials. And, Fictiv provides ways to increase dimensional accuracy by using different types of additive manufacturing. SLA (stereolithography), SLS (selective laser sintering), and MJF (multi-jet fusion) can be used for functional prototypes or even end-use production parts. Fictiv can help you unlock innovation with these 3D printing processes and more, so sign up and get started today!
