Online 3D Printing Services: Getting a Part Made Without a Printer

Who online 3D printing services are for

Using an online service makes sense for a one-off part or a small run, a material or technology your own printer does not offer (industrial resin, powder, metal), or simply not owning a machine at all. It is also a way to test a part in a technical material before considering a dedicated machine for that specific use.

On the other hand, a recurring need on the same common material, with tight deadlines or a sizable volume of parts, often ends up costing more over time than owning a printer outright. The beginner's guide covers the criteria for that decision once it becomes a serious question.

An online service also saves you from learning to tune a machine for a one-off need: no calibration, no plate maintenance, no filament choice to make yourself. That is a real advantage for someone with neither the time nor the interest in learning 3D printing for a single, isolated part.

The main types of online services

Some platforms work as a marketplace that connects the user with a network of manufacturing partners, each offering its own technologies and materials, with quotes automatically compared against each other. Other services run their own fleet of machines directly and offer a narrower but more predictable catalog of materials from one order to the next.

Available technologies go well beyond home FDM: filament deposition, powder sintering (SLS), stereolithography and vat photopolymerization (industrial resin), all the way to metal sintering for demanding mechanical parts. A general-purpose service usually lists the technology and material available for each part once the file is uploaded, making it possible to compare before placing an order.

Preparing and sending your file correctly

STL remains the most universally accepted format by 3D printing services, since it describes a part's surface as triangular facets that nearly every tool in the industry can read. For a mechanical part with tight tolerances or threads, a native CAD format like STEP preserves exact geometry instead of an approximation, reducing dimensional discrepancies reported after manufacturing.

A native assembly file (several parts linked together in one document) usually causes trouble on import, since it does not always carry usable solid information; exporting each part separately before sending is the safer route. The choice between formats is covered on the STL vs. 3MF page, a question that applies just as much to an online order as to local slicing.

Before sending anything, it is also worth confirming you have the right to have the file manufactured: a model downloaded from a community platform is subject to the license its creator chose, a point covered on the licenses and rights page.

What actually drives cost, without naming a figure

The actual volume of material used, infill included for an FDM part, weighs directly on cost since material is usually billed by weight or volume. Geometric complexity matters too: a part that needs extensive supports uses more material and more post-processing time to remove them, which shows up in the final quote.

The technology and material chosen shift the order of magnitude of the price far more than any setting tweak: industrial resin or metal sintering cost structurally more than FDM in PLA or PETG, for reasons tied to the machine and premium material rather than simple positioning. Order quantity plays a role too, with a small batch lowering the per-part cost compared with a single piece thanks to amortized file setup. To gauge these orders of magnitude without relying on a single quote, the print cost tool lets you compare the variables one at a time.

Turnaround, finishing, and order tracking

Quoted turnaround times vary a lot depending on whether a service runs its own machines or routes the order to a network of manufacturing partners, the latter sometimes adding a production-scheduling step before shipping. It is worth checking whether the stated turnaround covers manufacturing and shipping, or just one of the two, before committing to a time-sensitive part.

The finish offered (raw, sanded, dyed, with supports manually removed) also affects the final look and sometimes the turnaround, since a part with post-processing needs an extra step compared with a raw output straight off the machine. A reputable service usually states a dimensional tolerance range specific to each technology rather than a blanket promise of accuracy.

Order tracking also differs from one service to another: some send a confirmation at every step (file approved, production started, shipped), while others offer only a broader, less detailed status. For a part with a critical deadline, checking this level of tracking before ordering avoids last-minute surprises.

Wall thickness and fine details: what the service will not fix for you

A service prints the file as received, with its own settings, and rejects or degrades areas that are too thin. The Prusa Knowledge Base explains why wall thickness is not a simple multiplication: two perimeters of 0.45 mm extrusion width give a 0.86 mm wall, not 0.90 mm, at a 0.2 mm layer, because the beads overlap to fuse, and that value shifts with layer height. A wall drawn at 0.5 mm therefore lands somewhere between one and two beads depending on the provider's machine, with an unpredictable result.

The same documentation notes that standard profiles use a minimum of two perimeters and that a part's strength comes mostly from that wall count, not from infill. For a file headed to a service, drawing walls comfortably thicker than the minimum and avoiding details finer than a single bead yields a part whose finish no longer depends on the shop's unknown settings. Our layer height guide covers that relationship between bead, layer, and wall.

Marketplaces that aggregate manufacturers advertise very broad catalogs, one of them claiming more than 200 materials and about thirty technologies through a network of vetted partners. That breadth does not replace file preparation: a wall that is too thin gets rejected in powder sintering just as it does in FDM, and the instant quote does not always flag it before the order.

When buying your own printer becomes more rational

The tipping point toward buying a machine comes once the need repeats regularly on a material that consumer FDM handles well, like PLA or PETG, and an outside service's turnaround becomes a daily constraint. The math goes beyond per-part cost: it also includes the time saved iterating on a prototype without waiting for a shipment, often a deciding factor for anyone designing new parts on a regular basis.

On the other hand, a one-off need in a material or technology few individuals own, such as metal sintering or a specific industrial resin, still justifies an online service even after buying a first FDM printer, since the two options complement each other rather than ruling one another out.

Sources and limits

• Xometry Manufacturing Community — What file types does Xometry accept?
• Prusa Knowledge Base — Layers and perimeters (recommended thin wall thickness)
• Craftcloud — About us (manufacturing partner network)
• Craftcloud — 3D printing services (technologies and materials)

We organize manufacturer and community documentation; we have not measured these products ourselves. The manual for your exact model takes precedence over general guidance.