It is a well-established fact that physical parts enable a far better understanding and appreciation of a mechanical component design than a 3D CAD model alone. Traditional methods for mechanical component prototyping, such as machining, are typically slow and often incur high costs.
Two common misconceptions often cited by 3D printing skeptics:
- 3D printing can’t provide structural interfaces to support fastening methods needed for the assembly. In reality, keying features can be included within the 3D print geometry or inserts can be heat staked into the printed part to facilitate rigid or flexible joints in the final assembly.
- 3D printed parts aren’t sufficiently accurate nor strong enough to meet typical design requirements. In reality, 3D printed parts can be post processed to increase accuracy at a much lower cost than machining the whole part and there are many more choices for reinforced plastics used in 3D printing that exhibit near-metal properties.
We have found that 3D-printed part quality and strength are often sufficient and can be readily integrated with non-printed components to create a system where initial functionality data can be gathered.
How 3D printing can save time
One of the largest contributors to time savings is that the 3D printer is working while you are not. The parts produced by the 3D printing process can be evaluated for spatial features such as size, location, and orientation as they relate to how a person will interact with the part or how the part fits within the larger system with little delay from initial concepting. Additionally, the 3D-printed parts can provide short order feedback during new product development projects when they are used as field data samples, communication samples, or DFM/DFA samples, to mention a few.
Time saved equates to money saved, and is often a consideration when making prototype parts. The metric comes down to, “Is one process faster than another?” Time and cost savings can be compounded when rapid design iterations can be accomplished with the speed of 3D printing.
3D printing requires much less documentation and effort to produce parts than traditional machining. Assuming you own your own 3D printer, then the whole purchasing process can be eliminated from your timeline. 3D printers can be running 24/7 to create your parts while you are sleeping or doing other value-added work.
As an example, it may take two weeks to source a machined widget. Assume for a minute that it takes roughly 12 hours to print that same widget, then in the time it takes to get your first machined widget, you could conceivably have completed 5 to 8 unique iterations of 3D printed parts.
Machined Widget: 14 days
3D Printed Widget: 0.5 days
Approximately 95% time savings to 3D print over Machining
Let’s consider the likely scenario that the initial widget design now needs to be iterated with 2 days of evaluation in between iterations.
Machined Widget: 14+2+14 = 30 days
3D Printed Widget: 0.5+2+0.5 = 3 days
Approximately 90% time savings to 3D print over Machining
Sometimes prototype requirements may dictate that the delivered part cannot be 3D printed. 3D printing can still be utilized in this case to confirm high-level design direction and should be employed as a first-pass design evaluation prior to committing to a more time consuming and costly prototyping method.
In the following example, 3D printing is leveraged to gain confidence in the design before committing to machining. Now with the same timing criteria as the first example, we print the first iteration, evaluate, and then machine the second iteration to avoid having a high-potential rework of 1 week for the machined widget.
3D Printed Widget + Machined Widget: 0.5+2+14 = 16.5 days
Machined Widget+ Rework: 14+2+7=23 days
Approximately 30% time savings to 3D print before Machining
Comparing the traditional prototyping approach with 3D printing
With traditional prototype methods (e.g., machining), production of prototypes generally follows these steps (often taking up to a month before you can evaluate parts) for a six-part assembly:
- Create manufacturing prints of design to be prototyped ~2 days
- Identify manufacturing sourcing options for the prototyping ~ 1 day
- Send manufacturing prints out and get quotes back ~5 days
- Select supplier and provide PO ~1 day
- Wait for the parts to be manufactured ~21 days
Total Time for prototyping with Machining is approximately 30 days
The 3D printing prototyping approach
With 3D printing, more than one part can often be made at one time. We are going to assume 3 parts are made per 24 hour run. the steps are:
- Create STLs (Standard Triangle Language) of design to be prototyped ~ 1 hr
- Prepare the STL files for printing in slicer software ~ 2 hrs
- Print prototype parts ~2 days
- Remove supports or post process to desired quality ~ 6 hrs
Total Time for prototyping with 3D printing is ~ 2.5 days
In this case, 3D Printing saves over 90% of your valuable project time versus machining.
STL files of the 3D model are required to print samples, omitting the need to create manufacturing prints.
Samples of more than one design option can be printed at the same time. Often this can be initiated at the end of a workday so that the parts are ready for evaluation in the morning of the following day. For larger assemblies with multiple parts the build time will increase accordingly, but it will still be significantly less (as shown by the examples above) than traditional manufacturing methods.
What people have to say
With 3D printing, seeing is believing. Some comments that we’ve received from our customers after receiving and carefully inspecting their 3D printed parts for the first time:
“I’m surprised this part was made with a 3D Printer. The finish is much better than what I have seen before on 3D printed Parts”.
“Did this come out of a mold? The part quality is much better than I expected coming from a 3D printer”.
“When I put your designed assembly together the 3D printed parts just worked”!
Our 3D printer has very rapidly become an invaluable tool that is relied upon in our daily operations. In hindsight, it is hard to imagine how we ever managed our development process without it.