When to Outsource a Print

Outsource a print when your requirement (material, strength, surface finish, tolerance, size, or repeatability) is beyond what you can reliably hit on your own machines, or when the expected cost of 2–3 iterations plus post-processing is higher than a service quote. Decide using a quick process/requirement matrix, then de-risk with a small “coupon” test that contains the critical features before you buy a full run.

TL;DR

Outsource when you need tolerance, surface finish, strength/isotropy, size, or batch repeatability that you can’t hit consistently on your own machines. Before you pay for a full part or a full batch, order a small “coupon” that includes the critical holes/fits/walls and confirm it measures and assembles correctly.

What outsourcing really changes

Outsourcing usually switches you to a different process and a more controlled production setup: calibrated machines, known material lots, stable temperature/humidity, and standard post-processing. You lose instant iteration and deep control of every setting. You gain capability and repeatability. Plan for different lead times, minimum charges, and process-specific design rules (minimum walls, escape holes, support marks, shrink compensation).

Strong signals you should outsource

  • Material gap: you need nylon, high-temp, chemical resistance, ESD behavior, or metal properties you can’t print safely/reliably in-house
  • Fit/tolerance is make-or-break: bearing seats, seals, alignment features, or hole sizes where “close enough” causes failure
  • Surface finish drives function or appearance: paint-ready cosmetics, smooth channels, low-friction sliders, or visible surfaces you can’t hide
  • Strength needs isotropy: parts that flex, vibrate, or snap repeatedly without splitting along layers
  • Too big or too warp-prone: it won’t fit your build volume, or splitting/bonding would distort the result
  • You need consistency across parts: 10+ pieces where matching matters more than tuning a printer
  • A long-print failure would cost the schedule: missed deadlines hurt more than paying for a known process

Process options (and what they’re best at)

SLS/MJF nylon (outsourced) harder
  • Strong and more isotropic than typical FDM parts
  • No support scars, so complex geometry stays clean
  • Good for functional clips, hinges, lattices, and internal channels
  • Matte, grainy surface unless you specify finishing
  • Accuracy depends on the vendor and the finishing steps
  • You must design for powder removal (escape holes)
SLA/DLP resin (in-house or outsourced) medium
  • Very high detail with smooth surfaces
  • Great for cosmetic parts, molds/masters, and fine text
  • Many resin types (rigid, tough, high-temp)
  • Resin handling adds wash/cure steps and chemical safety requirements
  • Some resins are brittle, and long-term creep can matter
  • Supports can mark surfaces, so orientation is a big design choice
Metal printing (DMLS/SLM or binder jet) harder
  • True metal properties and high-temperature capability
  • Can combine multiple parts into one and add internal features
  • Fits demanding environments (heat, wear)
  • Higher cost, stricter rules, and longer lead times
  • Precision fits often need post-machining
  • Vendor constraints vary (supports, minimum walls, distortion)
CNC machining / laser cutting (outsourced) medium
  • Excellent tolerances and surface finish
  • Often faster/cheaper for flat parts or prismatic geometry
  • Predictable mechanical properties
  • Geometry limits (undercuts, deep internal channels)
  • Fixturing and tool access can dominate the cost
  • Printed shapes may need redesign to machine cleanly

Quick decision checks (what usually pushes you to outsource)

Must be watertight
Outsource if a leak is a real failure mode; otherwise plan a sealing method (epoxy/liner) and test it.
Must be load-bearing
Outsource when failure would be unsafe or expensive; ask for material data and build-orientation guidance.
Precision fits or threads
Outsource and/or plan post-machining, heat-set inserts, and a tolerance coupon before a full order.
Perfect cosmetics
Outsource when your sanding/priming effort costs more than the quote, or when support marks are unacceptable.
10+ identical parts
Outsource when you need repeatability, matched parts, and reliable throughput.

Cost and time reality check (a practical rule)

  1. Add up your in-house total: material + electricity + expected failures + your time (setup, monitoring, cleanup).
  2. Add the post-processing you will actually do: supports, sanding, filling, sealing, paint, and dimension tuning.
  3. Get a quote that includes shipping, finishing, and any minimum charges.
  4. Outsource when the quote is cheaper than ~2–3 likely iterations, or when a failed long print would blow the schedule.

What to send a service so they can hit your requirements

  • Files: STEP if possible (plus STL/3MF if needed); include a clear version name/date so revisions don’t drift
  • Critical dimensions: identify holes, mating faces, flatness, and any “do not sand” surfaces
  • Functional requirements: loads, temperatures, chemical/UV exposure, and whether the part flexes repeatedly
  • Process/material request: specify the material family and any color/dye requirements
  • Finish specification: as-printed, bead blast, tumble, vapor smooth, polish, paint-ready, or masked critical faces
  • Quantity and matching needs: whether parts must match across batches and whether they should be made in one run
  • Inspection request: ask for measurement of 2–3 critical dimensions if the service offers it

Proof-before-production (a coupon test that saves money)

  1. Model a small coupon with the risky features: tightest fit, smallest hole, thinnest wall, text, snap tab, and one cosmetic face.
  2. Order the coupon in the exact material and finish you want for the final part.
  3. Measure and test assembly; if it fails, change the CAD (not just slicer settings) and re-run the coupon.
  4. When it passes, lock the file version and finish spec, then order the full part or batch.