Failed 3D Prints and Failure Margin: Cost and Fixes
Not every print succeeds. A print that lifts off the bed, turns into spaghetti halfway or fails on the first layer wastes filament, electricity and time. A seller who does not price this in earns less real profit than they think.
1. Measure your failure rate
Failure rate = failed prints ÷ total prints started
Example: in a month you started 40 prints and 3 failed → 3 ÷ 40 = 7.5%. A notebook or a simple table is the only way to really see the rate instead of guessing. Track it separately when you try a new material or setting.
2. Add the margin to cost
There are two common methods:
| Failure rate | Factor: 1 + rate | Factor: 1 ÷ (1 − rate) |
|---|---|---|
| 5% | 1.050 | 1.053 |
| 7.5% | 1.075 | 1.081 |
| 10% | 1.100 | 1.111 |
| 20% | 1.200 | 1.250 |
The third column is mathematically more accurate: successful parts carry the cost of the failed ones. At low rates the difference is small; for simplicity Filanomy uses the first method (cost × (1 + failure margin)). If your failure rate is above 10%, finding the source of the problem pays more than growing the margin.
3. A failure is not always a total loss
If a print failed at 80%, you lost roughly 80% of the filament and electricity spent. You can use an average "partial loss" when setting the margin. On small parts the loss is small anyway; on large, long prints failure is expensive, so be extra careful before long prints.
The most common causes of failure
- Bed adhesion: a dirty or oily surface, wrong Z offset, cold bed.
- Warping: no enclosure with materials like ABS/ASA.
- Wet filament: weak layers, stringing, clogs (filament moisture guide).
- Clogs and feeding issues: a worn nozzle, wrong temperature, retraction settings.
- Supports and geometry: not enough support for overhangs.
- Power outages and software errors: the risk grows on long prints.
Practical ways to fail less
- Invest in the first layer: clean the surface, calibrate the offset, print the first layer slowly.
- Keep filament dry: a dryer and a sealed box.
- Maintain regularly: check the nozzle, belts and bed surface periodically. Add wear to cost as an hourly machine rate.
- Short test before long prints: catch the problem early with a quick test using the same settings.
- Camera and monitoring: the earlier a failure is caught, the smaller the loss.
- Change one thing at a time: so you know which change caused the issue.
In Filanomy
Enter your measured rate in Failed-print risk under "Advanced settings". The margin is added on top of the subtotal and shows separately as "Failure risk". The more you update it with real data, the more realistic your price stays.
Frequently asked questions
How do I find my failure margin?
Count a month of prints: how many did you start, how many failed? Failed ÷ total is your failure rate. For example 3 failures out of 40 prints is 7.5%. Track it for a few months and use the average.
Is the cost of a failed print the whole print?
Usually not. You lose the filament and electricity used up to the moment of failure. The later it fails, the bigger the loss. You can assume an average "partial loss" and reflect it in the margin.
Is the margin factor (1 + %) or 1 ÷ (1 − %)?
The second is more correct: it gives the average cost including the failed prints. At low rates the two are very close (1.050 vs 1.053 at 5%); as the rate grows the gap widens (1.20 vs 1.25 at 20%). Filanomy uses (1 + %) for simplicity.
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