Why work in stages?
A start-up or design studio with a new product is short on two things: time and budget. The most expensive mistake is ordering a mould for a design that isn't right yet. With 3D printing you test every idea physically first, for a fraction of the cost of tooling.
The rule of thumb: at each stage, pick the cheapest technology that answers that stage's question. A look-alike model doesn't need to be strong. A functional prototype doesn't need to be pretty. Only at the first run does everything have to come together.
Below are the four stages. Each worked example uses the same fictional product, a handheld device about the size of a remote control, and is the volume times the material's starting price, excl. VAT and finishing.
1. Look-alike model: is the shape right?
The question: how big is the product really, does it sit well in the hand, can you reach the buttons? A screen or sketch won't answer that honestly. You want something to hold quickly and cheaply, probably several variants side by side.
The approach: FDM in PLA, printed in house. FDM is the most economical way to make a shape tangible. Layer lines stay visible and fine detail is limited, but for size and ergonomics that doesn't matter. FDM isn't in Quotebase yet: request a custom quote via info@makernaut.be.
Worked example: 120 cm³ × €0.15/cm³ = from €18.00 per part, excl. VAT. Three variants therefore cost three times that. You get the actual price in a custom quote, as FDM isn't in Quotebase yet.
2. Presentation model: does it convince?
The question: you're meeting investors, going to a trade fair, launching a crowdfunding campaign or pitching a first customer. The model has to look like the final product, with crisp edges, detail and maybe colour.
The approach: SLA in White Resin, printed in house. SLA gives a smooth surface and sharp detail, and white resin is a good base for painting in your brand colours. If you want colour straight from the printer, Full Colour Resin is an option, from €0.75/cm³. For a photo or a trade fair, the difference between a painted model and a real product is often invisible.
Worked example: 90 cm³ × €0.45/cm³ = from €40.50 per part, excl. VAT. In Full Colour Resin that becomes from €67.50. Sanding and painting are extra. Your actual price is shown in Quotebase; volume × material price is just a starting point.
3. Functional prototype: does it work?
The question: do the board and battery fit, do the shells snap shut, does the device survive a fall off the table? Now you're testing the product the way it will be used.
The approach: MJF in grey PA12. PA12 is an engineering plastic with properties close to injection-moulded nylon. Clips, hinges and screw bosses therefore behave roughly as they will in the final product. What you learn here about wall thickness and fits carries straight over to the production run.
Worked example: 85 cm³ × €0.52/cm³ = from €44.20 per part, excl. VAT. Plan for two or three rounds: after each test you adjust the design. Your actual price is shown in Quotebase; volume × material price is just a starting point.
4. First run: sell and learn
The question: the design works and you want to deliver the first tens to hundreds of units to real customers, without sinking tens of thousands of euros into an injection mould yet.
The approach: there are two routes. MJF in black PA12 produces end-use parts without a mould, with an even matte look; any design change can go straight into the next order. Vacuum casting pours parts into a silicone mould made from a printed master. It gives a surface finish and materials closer to injection moulding, for instance in colour or in a rubber-like grade. For vacuum casting, request a quote in Quotebase and you'll get an answer within one working day. The price depends on quantity, size, casting material and finish.
Worked example: 85 cm³ × €0.70/cm³ = from €59.50 per part, excl. VAT. That's the MJF route. Your actual price is shown in Quotebase; volume × material price is just a starting point.
Overview of the worked examples
| Stage | Technology and material | Volume | From, per part, excl. VAT |
|---|---|---|---|
| Look-alike model | FDM, PLA (custom quote) | 120 cm³ | €18.00 |
| Presentation model | SLA, White Resin | 90 cm³ | €40.50 |
| Presentation model in colour | SLA, Full Colour Resin | 90 cm³ | €67.50 |
| Functional prototype | MJF, PA12 grey | 85 cm³ | €44.20 |
| First run | MJF, PA12 black | 85 cm³ | €59.50 |
| First run | Vacuum casting | — | Request a quote |
All amounts are starting prices per part, excl. VAT and finishing. The fictional product has a slightly different volume at each stage, because a look-alike model is often solid while a prototype is hollow with walls.
Design tips for product developers
- Design with walls rather than solid blocks from the start. Every model gets cheaper and your prototype looks more like the final product.
- Change as little as possible per round. Then you know which change made the difference.
- Print variants in one order. Two or three versions side by side settle a question faster than three separate rounds.
- Think ahead to production. If you plan to injection mould later, allow for draft angles and even wall thickness, even though 3D printing doesn't need them.
- Save every version with a clear name and date. At production time you want to be sure which file was approved.
Which technology at which stage?
- Choose FDM when you want to check shape and size quickly and cheaply.
- Choose SLA when the model has to look finished or show fine detail.
- Choose MJF in PA12 when the prototype has to work like the final product, and for a first run without a mould.
- Choose vacuum casting when the first run has to come close to the look or material of injection moulding.
Makernaut does FDM, SLA and finishing in house. MJF and vacuum casting run through selected partners.