Guest article by Casitio, a small 3D printing workshop in Montevideo that prints replacement parts, brackets, and one-off fixes for people who don't own a printer.
A clip on the dishwasher rack snaps. The knob of an old radio cracks. A drawer runner loses the one plastic tab that holds it in place. The manufacturer no longer sells the part, and the obvious modern answer is "just 3D print it." The real question is whether you should print it yourself — which usually means buying a printer — or have someone else print it.
We print these parts every week, and the honest answer depends less on filament price than most people expect. Here is the math we walk customers through.
Filament Is the Cheap Part
A typical 1 kg spool of PLA or PETG costs around $15–25. A small replacement clip or knob weighs 10–50 g, so the plastic in it costs somewhere between 15 cents and a dollar. A desktop printer with a heated bed averages roughly 100–150 W while printing; a three-hour print uses well under half a kilowatt-hour.
That is where calculators that only multiply grams by price per kilo stop, and why they make home printing look almost free. The numbers that actually decide the cost are the ones around the print:
- The printer. A reliable entry-level machine is a few hundred dollars. Spread over two parts a year, that is the dominant cost for years.
- Failed attempts. A first-time part rarely comes out right on the first print. Wrong tolerance, warped corner, a hole 0.3 mm too small — two or three tries is normal, and each one costs the full print time again.
- Modelling. If no ready model exists, someone has to measure the broken part with calipers and draw it in CAD. For a simple bracket that is half an hour; for a part with clips and curves it can be an evening.
- Wear items. Nozzles, build plates, belts, and the occasional clogged hotend. Small individually, steady over time.
- Your time. Learning a slicer, levelling, drying filament, and watching the first layer is a hobby. If you enjoy it, it is not a cost. If you only wanted the dishwasher clip, it is.
The Hidden Cost Nobody Prices In: Noise
A print of a few centimetres can take three to eight hours, and larger parts run overnight. Most desktop FDM printers sit somewhere around 45–60 dB(A) at one metre while printing: stepper motor whine, part-cooling fans, and the rattle of fast travel moves. That is the range of a quiet conversation to a busy office — fine for an hour, tiring when it is next to your desk all afternoon or in the room where you sleep.
Before deciding where a printer would live, measure the room. Open the Noise Meter on your phone or laptop, record the baseline in the spot you have in mind, then compare it with a video or a friend's printer at the same distance. A browser meter is not a calibrated instrument, but it is good enough to tell you whether you are adding 5 dB or 20 dB to the room. The bzic-tools guide on how to measure noise levels explains placement and the difference between dB(A) and dB(C), which matters for low fan rumble.
Noise is not the only environmental factor. PLA is mild, but ABS releases styrene and needs an enclosure and ventilation. If the only free space is a bedroom or a small flat, that alone can settle the decision.
A Quick Break-Even Check
| Your situation | Usually cheaper |
|---|---|
| 1–3 broken parts a year, no CAD experience | Order the part |
| A ready STL exists and you need several copies | Order, unless you already own a printer |
| Part must survive load, heat, or outdoor sun | Order — material and settings matter more |
| You iterate on designs every week | Buy a printer |
| You want 3D printing as a hobby | Buy a printer — the learning is the point |
The pattern is simple: a printer pays off with frequency. If you print something every week, you will outrun the purchase price quickly and the failed prints become practice. If you need a part twice a year, the printer mostly sits there collecting dust and drying out its filament.
Choosing the Material for a Replacement Part
Whether you print it yourself or order it, the material should follow how the part is used, not what happens to be loaded in the printer:
- PLA — stiff and easy to print. Good for decorative and low-stress indoor parts. Softens around 55–60 °C, so not for a car dashboard in summer.
- PETG — a little flexible, tougher, tolerates moisture and moderate heat. Our default for parts that get handled every day.
- TPU — rubbery. Bumpers, feet, seals, cable grommets.
- ABS — handles heat well, but warps and smells while printing. Best left to enclosed printers.
Getting a Price Before You Commit
The most useful thing you can do before choosing either path is to get a real number for your part. If you have an STL file, a quote calculator will read its volume and give you a price range for each material; compare it with the cost of the printer you were looking at.
On our own page we built a 3D printing price calculator that does exactly this: drop in an STL (or type the rough dimensions), pick PLA, PETG, TPU, or ABS, say whether the part is decorative, everyday, or load-bearing, and it shows an approximate range straight away. The file is read in your browser, not uploaded, so you can check a price without sending anything to anyone.
No model at all? That is common for old appliances. Take photos of the broken part next to a ruler, measure the critical dimensions — hole diameters, the distance between mounting points, the thickness of any clip — and any shop can model it from those.
Conclusion
A 3D printer is a great tool if you will use it often, and an expensive, noisy shelf ornament if you need a part twice a year. Count the failed prints, the modelling time, and where the machine will actually run. Measure the noise in that room, get a quote for the part, and the decision usually makes itself.
Frequently Asked Questions
How much does it cost to 3D print a small part at home?
Material for a small PLA or PETG part (20–50 g) costs well under a dollar, and electricity adds a few cents. The real cost is everything around it: the printer itself, failed attempts, modelling time, and wear items. For one or two parts a year, ordering is usually cheaper than owning a printer.
How loud is a home 3D printer?
Most desktop FDM printers measure roughly 45–60 dB(A) at one metre while printing, depending on fans, speed, and enclosure. The peak number is moderate; what makes it noticeable is that a print runs for 6–12 hours, often overnight.
Which filament should I choose for a replacement part?
PLA for decorative or low-stress indoor parts, PETG for parts handled every day or exposed to moisture and warmth, TPU for flexible parts, and ABS only with an enclosure and ventilation.
What do I need to get a quote from a 3D printing service?
Ideally an STL or 3MF file. Without one, photos next to a ruler plus key measurements are usually enough. Also say how the part is used — decorative, everyday, or under load — because that decides material, wall thickness, and infill.