3D Printing Post-Processing: What the 2022 Survey Report Actually Tells Engineers
PostProcess surveyed 3D printing users about the step nobody models in CAD: getting a printed part clean, smooth, and usable. Here is what the 2022 survey report on 3D printing post-processing covers, where its findings line up with what we see on the shop floor, and how to turn them into a decision for your own parts.
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Why the 2022 survey report on 3D printing post-processing still gets quoted
PostProcess built automated support-removal and surface-finishing systems, so the survey it published in 2022 was written by a vendor with a clear commercial stake. That does not make the numbers wrong. It means you read them as a map of where users felt pain, not as a neutral benchmark.
The sample leaned toward professionals running polymer AM in production, not hobby printers. Respondents were mostly engineers and shop managers dealing with repeat orders. Their answers describe the same bottleneck we hear from buyers who send us printed parts for secondary machining and finishing.
The headline finding was labor. Post-processing consumed more hands-on time than printing itself for a large share of respondents. Printing runs unattended overnight. Support removal, sanding, and inspection do not. That mismatch is the whole story of the report.
A second thread was consistency. Two identical parts could leave the same printer and end up with different surface quality after finishing, depending on who did the work and how long they spent. That variance is what pushes teams toward fixtures, media blasting cabinets, and documented finishing recipes.
What post-processing actually does to a printed part
Post-processing is a group of operations, not one step. Support removal separates the part from its own scaffolding. Then comes depowdering or resin draining, then surface work, then any secondary machining, then inspection. Each operation has its own tolerance stack and its own way to ruin a part.
Support removal is the highest-risk step. On FDM parts, the break line often leaves a witness mark on the outer skin. On metal powder bed parts, sawing or wire EDM cuts the part free of the build plate and can leave a heat-affected zone. On resin parts, the support nubs are small but the material is brittle.
Surface finishing changes dimensions. Media blasting removes material from every exposed face. Tumbling rounds edges. Vapor smoothing softens sharp corners. If a printed feature sits at Ø 6.00 mm and the finishing removes 0.15 mm per side, the delivered part is Ø 5.70 mm. Engineers forget this more than any other step.
Secondary CNC machining is where printed parts meet real tolerances. As-printed surfaces on polymer AM typically land around ±0.2 to ±0.5 mm, and metal binder jet or DMLS parts can hold tighter but still drift. Boring, facing, and drilling on a 3-axis or 5-axis mill bring critical bores and mating faces to ±0.005 mm when the setup is planned around printed stock.
How the survey findings translate into design rules
If labor is the constraint, design for less labor. Put the critical surfaces where a machine can reach them in one setup. Orient the build so supports land on non-critical faces. Add 0.3 to 0.5 mm of stock on any face that will be machined after printing.
Consistency problems come from undocumented manual work. Write down the finishing recipe: media type, pressure, time, and pass count. A 5-minute bead blast at 4 bar behaves differently from a 12-minute blast at 6 bar, even on the same part geometry.
Hidden internal channels are the classic failure. A printed manifold with a 2 mm internal passage cannot be inspected and cannot be reliably cleaned. If the channel matters, design it at 4 mm or larger, or accept that the part is single-use.
Material choice closes the loop. ABS and PA tolerate media blasting and tumbling well. PEEK holds up but costs more to finish. Resins are dimensionally stable after post-cure but chip at thin walls. Match the finishing method to the polymer before you commit to a print orientation.
Where the money goes after the print stops
Post-processing cost scales with surface area and feature count, not with part volume. A large flat panel is cheap to finish. A small bracket with twenty pockets and twelve mounting holes can cost more to clean than to print, because every pocket traps powder or resin.
Support removal dominates cost on overhanging geometry. A part printed flat on the plate might need ten minutes of work. The same part tilted 45 degrees to improve surface finish can need an hour of support cutting and cleanup. Orientation is a cost decision, not only a quality decision.
Finishing also drives lead time. An as-printed part can ship the day it comes off the machine. A part that needs vapor smoothing, dyeing, or CNC facing adds two to five days depending on queue and process. Build that into the schedule early.
Inspection is the quiet line item. Measuring a printed part on a CMM after finishing takes time, and 100% inspection only makes sense on functional or regulated parts. For visual prototypes, a documented visual check plus a few critical dimensions is usually enough.
Matching post-processing method to part requirement
Pick the row by what the part must do, not by what the printer can make.
| Part requirement | Method | What it fixes | Watch out for |
|---|---|---|---|
| Fit on mating faces | CNC facing after print | Flatness and bore position | Add 0.3–0.5 mm machining stock |
| Smooth visible skin | Bead blast or vapor smoothing | Layer lines, gloss uniformity | Removes material, rounds edges |
| Clean internal channels | Ultrasonic plus flushing | Trapped powder or resin | Needs 4 mm minimum passage |
| Sealed or colored surface | Dyeing, painting, anodizing | Color and minor porosity | Masking adds handling steps |
| High-cycle functional part | Stress relief plus finish | Residual stress, fatigue life | Heat cycle can shift dimensions |
| One-off visual model | Hand sanding only | Obvious defects | Not repeatable between parts |
The takeaway
If the printed part only needs to look right, hand finishing is the cheapest path. If it has to mate, seal, or cycle, plan CNC secondary operations and stock allowance before the first print, because no amount of sanding will hold ±0.005 mm.
Questions engineers ask after reading the report
Is the 2022 survey report on 3D printing post-processing still relevant?
The specific percentages age, but the structure of the problem has not changed much. Labor time, repeatability, and hidden internal geometry were the top three concerns then and they still come up in every quote request we handle.
Read it as a checklist of failure modes rather than a forecast. If your process addresses support marks, dimensional drift after finishing, and channel cleanliness, you have covered most of what the report flagged.
How much material does bead blasting remove from a printed part?
On polymer AM, a typical bead blast pass removes 0.02 to 0.1 mm from exposed faces depending on media size, pressure, and dwell time. Glass bead at 4 bar for a short pass sits at the low end; aggressive media at higher pressure moves toward the high end.
If a feature has a tolerance tighter than ±0.1 mm, either mask it or plan to machine it after blasting. Blasting a bore that must press-fit a bearing is a reliable way to lose the fit.
Can printed parts be machined to the same tolerance as billet parts?
Yes, on the features you can reach in a single setup. Our 5-axis centers hold ±0.005 mm on machined faces, and we routinely face, bore, and thread printed stock.
The limit is the printed substrate. Polymer and binder jet material can chip or compress under cutting forces, so feeds and speeds run lighter than on 6061 or 304 stainless. Deep pockets and thin ribs still need support from the print itself.
When should we skip post-processing entirely?
Skip it when the part is a form-and-fit check with no sealing, no bearing interface, and no cosmetic requirement. As-printed surfaces at Ra 1.6–3.2 μm are fine for that.
Do not skip it when the part carries load, holds pressure, or touches a mating machined component. Those cases need at least a dimensional check and usually a machined interface.
Does post-processing affect the certification trail?
It can. Finishing steps that change dimensions or surface chemistry belong in the inspection record. For medical and automotive work we keep process records and issue inspection reports on request.
If your quality system requires traceability, tell us at quoting. Our plants operate under ISO 9001:2015, IATF 16949:2016, ISO 13485:2016, and ISO 27001:2022, and we can align documentation with your incoming inspection format.
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More process notes from GreatLight
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