Excerpt from White Paper by Todd Grimm
In last week’s blog, Todd highlighted the disconnect between the promise and common perception of 3D printing as a fast, automated push-button technology and the realities of post-processing parts after 3D printing. This week, Todd dives deeper into the primary impact of post-processing at six automotive, consumer product, medical device, sporting goods and architecture companies.
It comes as no surprise that the biggest issues with post-processing are the added cost and the added time, which can be quite significant. Both time and money were noted by the six contributing companies as their primary concerns. However, the ranked priority for each varied and were driven by the current climate within the businesses. For example, cost was secondary for those that urgently need to accelerate delivery of 3D-printed models and prototypes.
The business climate and corporate goals also influenced the perceived impact of post-processing. For example, the wages paid for post-processing labor were viewed as a barrier to advancement and innovation; a throttle on total production; or a drain on financial resources. While the negative effects of post-processing are universal, the implications of this required step are interpreted through the lens of the organization’s current challenges and goals.
Cost Impact of Post-Processing
Post-processing adds cost to 3D printing operations in a number of ways, but the most-cited aspect is labor cost. Using a fully burdened labor rate, the companies reported an hourly cost of $30.00 to $100.00. With 4 to 10 3D printers, the annual labor cost, fully burdened, ranged from $100,000 to $500,000.
This equates to a direct labor cost for post-processing of roughly $25,000 to $50,000 per year for each 3D printer. If the machine operator, or another higher-wage employee, performs post-processing, the annual cost can rise significantly.
When adding a 3D printer, this burdened labor costs must be included in annual operating budgets. The additive manufacturing technology leader at a medical device company said that when budgets are taken into consideration, “Adding one more parts finisher means that there is one less machine that I can purchase.”
For those that are already saddled with post-processing labor, the benefit of eliminating this task may not be cost reduction. Instead, it could be capability expansion. Considering budgetary limits that preclude hiring, the contributors indicated that they would reallocate the post-processing staff to value-added activities. For example, the medical device company stated that it would redeploy its personnel to activities that either improve its 3D printing operations by advancing the technology or redirect the staff to secondary post-processing activities that improve the quality and appearance of 3D printed parts.
Michael Zerbe, RP technologies supervisor at Newell Rubbermaid, noted that staffing limitations impact part quality and 3D printer utilization. He said that without primary post-processing, the staff could invest its time to improve the 3D-printed models with additional finishing and painting. But more importantly, he could increase his 3D printing output. He said, “With my post-processing resources, I can only run my 3D printers at a 60% utilization rate. Eliminate post-processing and I would have the capacity to run them around the clock. This would mean more throughput, which would allow us to do more iterations for each project.”
Another expense element related to labor is the increased cost for models and prototypes when demand exceeds the capacity of the post-processing team. An engineering manager at a consumer products company noted that during peak periods he may have the needed 3D printer capacity but lack the required post-processing resources. In these situations, he either has to pay for overtime or subcontract the work to a service bureau. He noted, “Outsourcing increases the part cost by three or four times, and we can’t deliver as fast as if we kept the work in-house.”
A key benefit of 3D printing is speed so anything that slows the process is undesirable. Although a single part may be post processed quickly, the aggregate effect can extend lead times by days or weeks.
Time Impact of Post-Processing
As the contributors shared, post-processing adds 17% to 100% to 3D printing time on a batch-by-batch basis. What those numbers do not reflect is the full impact of this manual, bottleneck operation on schedules. A few hours of post-processing can translate to a 24-hour delay, even with a well-staffed operation. When compounded across multiple design iterations, the delay can be measured in weeks.
At Reebok, a typical build time is eight hours for its material extrusion process. The 3D-print jobs are then followed by post-processing, which may include a four-hour soak to dissolve support structures. This semi-automated step adds 50% to the total process time, but the total elapsed time to deliver the part can increase by 350% to turn one-day delivery into two. According Gary Rabinovitz, the company’s RP lab manager, “Post-processing can add another day to the schedule, which means that the design review and release of the next design iteration are also delayed.”
For example, if a file is received the morning of day one, the build could be launched at 9:00 AM. With an eight-hour build, 3D printing finishes after hours at 5:00 PM. Support removal starts first thing on day two and finishes at noon. This eight-hour print has a 36-hour turnaround even if the schedule is wide open and staff is available. Of course, a second shift could accelerate the process, but as discussed earlier, that second shift would add an expense that budgets may not support.
Without post-processing, delivery and design iteration could occur one day sooner. The cumulative effect over multiple iterations may extend a week or more, as one consumer products company noted. Its engineering manager said, “If a build ends in the afternoon, and if there was no post-processing, we could have the next iteration building by the end of the day. With post-processing, it is pushed out a full day.” This company typically does 5 to 10 iterations for each product, which translates into a total delay of one to two weeks, if weekends are included.
For these companies, eliminating post-processing would dramatically accelerate the product development process, which in turn can reduce the time to market. At the day-to-day level, post-processing may be the difference between delivering in time for an important meeting or walking in empty handed.
Another factor that adds to the potential for delays is that post-processing can be a bottleneck that is subject to backlogs. The automated 3D printing process typically outputs many parts per build, which all enter post-processing at the same time. Considering the need for direct labor and access to supporting equipment, parts wait in queue until the resources become available. The AM technology leader at the medical device company said, “It kills me to see trays of parts late on a Friday, knowing that they won’t be delivered until late in the day Monday.”
The automotive company noted that the bottleneck becomes very evident following a long holiday weekend. Leveraging the unattended operations, as many parts as possible are nested to print in one long run over the three days. However, post-processing resources are overloaded when work resumes. A casting engineer at the company said, “There are backlogs even if post-processing is automated. Sometimes the post-processing equipment simply doesn’t have the throughput or capacity to match that of 3D printers running over multiple days.”
Without post-processing, the value of 3D printing could increase substantially. For some, it would allow them to perform more value-added tasks to improve part quality and expand the application base. For others, it would dramatically accelerate the total
process, which increases responsiveness and total throughput. For those adding new 3D printers, eliminating post-processing would reduce labor expense by $25,000 to $50,000 for each machine. However, post-processing’s burdens don’t stop with labor cost and total process time.
In next week’s blog, the last installment of our 3-part blog series, Todd outlines the tertiary, yet notable, impact of post-processing.