How much does custom 3D modelling of a part cost?

Modelling costs from €15 per hour, reverse engineering from a sample from €20 per hour, and repairing a faulty model €15 per hour. You approve the price in advance, and modelling is only charged after you agree to it. The basic check of whether your model is printable is free.

Can you make a part if I do not have a 3D model?

Yes, a drawing, a photo with dimensions or a physical sample is enough. We design the model and then print the part. You receive the model as STEP, STL or 3MF, and STEP is the source file that can be edited further.

What is the minimum wall thickness for FDM printing?

With a standard 0.4 mm nozzle, a wall narrower than a single perimeter, about 0.45 mm, will not print at all, and Prusa gives two perimeters as about 0.9 mm. Formlabs states a minimum of 1 mm and recommends 1.2 mm, a multiple of the nozzle. For loaded parts this is only a starting point, because orientation matters too.

I have a model from the internet. Is it worth paying to have it fixed?

Send it for the free check first, and you only pay if it turns out the model needs repair. Slicers can repair many errors automatically, but not all, and the “make solid” function reduces resolution. Repair costs €15 per hour, and the customer is responsible for having the right to use someone else's model.

When is my own model enough and no specialist is needed?

When the part is simple (a washer, a bracket, a spacer ring), you have CAD or STEP, and it is not an assembly with exact clearances. A slicer can handle rescaling or rotating the part. Even then, it pays to send the model for the free check before we quote.

When to hire a 3D modeller for 3D printing

Q: Who owns the rights to the model you create for me?

A custom-designed model is yours, and we agree the terms in advance in the quote. Under our terms and conditions you may use and share it freely once the service has been paid in full. If you supply your own or someone else's model, you are responsible for having the right to use it.

Hire a specialist when the model does not exist, when the part must fit an assembly exactly, when it will carry a load, or when you will print it in larger numbers. A simple part with a ready CAD model you can adjust yourself. 3D modelling costs from €15 per hour, and the printability check is free.

A printer prints exactly what it is given, even if the hole is a tenth of a millimetre smaller than the shaft or the wall is narrower than a single nozzle path. With custom 3D printing, most problems are therefore solved in the model, before the first print.

Do it yourself or hire a specialist: decide by situation

Situation	Can you do it yourself?	When to call a specialist
You have a sample, a sketch or a photo, but no model	Only for a very simple shape	When the dimensions have to fit: reverse engineering from €20 per hour, a new design from €15
You have CAD or STEP and the part is simple (bracket, ring, adapter)	Yes	Not needed, the free check is enough
The part fits into an assembly or moves	Only after several trial prints	When it has to fit first time, as clearances depend on the machine and material
The part will carry a load	Only if you know the direction of the forces	When orientation and walls have to be chosen to suit the load direction
A series of dozens of parts or more	Not always	When print time and material can be cut, see small batches
A model from the internet or one with errors	Free check first	When the check finds errors: repair is €15 per hour
You expect many changes	If you can use parametric CAD	When all you have is an STL mesh, where changing a dimension is laborious
Another supplier will take over production later	If you know their rules	We do not offer injection moulding, but we can prepare the data for the handover

Treat load with caution: a good design improves the odds, but it does not replace testing in service. For parts whose failure could endanger life, health or property, our terms and conditions require a separate written agreement.

What a specialist changes in the model: FDM rules

For us, optimisation for printing means lightening the part, adjusting walls and tolerances, and preparing supports. In practice it comes down to these points:

Rule	Value and source	Consequence if ignored
Wall	With a 0.4 mm nozzle, one perimeter gives about 0.45 mm and two about 0.9 mm (Prusa). Formlabs states a minimum of 1 mm and recommends 1.2 mm (Formlabs)	A wall narrower than one perimeter does not print, one that is too thick adds cost for nothing
Smallest feature	About 2 mm (Protolabs Network)	Fine details vanish or break
Overhang and bridge	Overhangs up to 45° without supports, bridges shorter than 5 mm without sag (Protolabs Network)	The surface above supports is rougher, a longer bridge sags
Clearance of moving parts	At least 0.3 mm according to Prusa, 0.5 mm according to the University of Zurich	Parts bind, and a trial print fine-tunes the value
Vertical holes	They print smaller than modelled, so for a critical diameter you print a smaller hole and drill it out	The shaft or screw will not go in
Edges at the bed	The first layer spreads out, and a 45° chamfer helps	The part will not slide into the assembly
Thin pins	Below 5 mm they print as perimeter only and hold weakly, while Formlabs and the University of Zurich give a minimum of 3 mm	The pin snaps off, so use a rounded base or a bought-in dowel
Text and relief	Relief at least 0.6 to 1.0 mm, lettering from 14 pt	Illegible lettering
Orientation	A part is weakest between layers, more in the article on materials for end-use parts	The part cracks along the layers

The numbers differ between sources because the machines, nozzles and settings differ. Treat them as starting values to be confirmed with a trial part. Tolerances for a specific part are agreed in the quote.

Model errors that a check catches

An open mesh. Holes in the surface or flipped faces mean the model cannot be sliced into layers.
Automatic repair does not always work. Slicers repair many broken models, but not all. The “make solid” function almost always works, but it reduces resolution (Prusa).
Wrong units. STL carries no units, so a model designed in inches and loaded as millimetres comes out 25.4 times smaller.
A coarse mesh. A smooth cylinder becomes a polygon in the mesh, with visible facets that are hard to fix afterwards.
A wall thinner than a perimeter. It exists in the model, but not on the print.

The difference between STL, STEP and 3MF is explained in the article on 3D modelling software, and a checklist to run before sending anything is in How to prepare a 3D model for printing.

Why later changes cost more

With 3D printing, you edit the CAD file and the next iteration is ready within days. With injection moulding, every change means reworking the mould, which Protolabs describes as a significant cost. The most expensive change is therefore the one you discover at assembly, when the parts are already printed.

Even in printing, time is not free. According to Protolabs, print time is by far the most significant cost factor, and supports add machine time. A specialist therefore looks for an orientation or a split of the part that needs fewer supports. If another supplier is to take over production later, say so at the first model. The links between prototype, pilot batch and tooling are covered in 3D printing versus traditional manufacturing.

When you do not need a specialist

Paying for modelling does not make sense in four cases:

A simple part from a ready CAD model. A bracket, washer or spacer ring can be printed without any intervention.
You only need to rescale or rotate the part. A slicer does that, and it is not modelling.
A box, cylinder or washer is all you need. Prusa calls Tinkercad the easiest way to start (Prusa Knowledge Base), and we compared the other programs in a separate article.
The model already works and you only want a check. We do that for free, see the price list.

What to send a specialist, what you get back, and how it works

Send a sketch or drawing, photos with dimensions, a sample, or an STL or STEP file. Add the purpose of the part, the environment (heat, outdoor use, load) and the dimensions that must fit. For spare parts a sample alone is enough. A detailed list of what to include in a quote request is in the article on what to send for a quote.

You get back the model as STEP, STL and 3MF. STEP can be edited further, while STL and 3MF go to print. The finished model is yours, and under our terms and conditions you may use and share it freely once the service has been paid in full. Modelling and repair are only charged after you approve them.

Enquiry and a free file check.
A quote within 24 hours with price and lead time.
The model and your approval.
A trial part, especially for assemblies, and then the remaining pieces.

The whole ordering process is described on the page How it works.

Two illustrative examples

A hole the shaft will not enter. A vertical hole modelled to the exact size of the shaft prints smaller, because the nozzle squashes the layer and widens the path (Protolabs Network). For moving parts, Prusa advises a clearance of at least 0.3 mm, fine-tuned by testing. In a parametric model the hole changes with one number, while in an STL mesh the intervention is laborious, so for assemblies it pays to have the source STEP.

A series of lightened brackets (hypothetical calculation). A 100 g bracket falls, according to the price list, into the 50 to 250 g band, which is roughly €0.12 per gram, so about €12. Lightening it by 25 g (a thinner wall, ribbing) saves roughly €3 per piece, or €60 over 20 pieces. If the change took an hour of modelling (€15), it would pay for itself from the fifth piece. The actual price is set by the quote, and the example only shows the logic.

How to get started

Send us a model or just a sketch. The printability check is free, and you approve the modelling price in advance. If you also need the printing itself, that is our custom 3D printing. If you already have a model and want to order a prototype from it, our article on ordering a 3D-printed prototype covers what to watch out for. Send your enquiry through contact or see 3D modelling to order.

This article was prepared by the 3D tlač na zákazku editorial team with the help of AI tools. Every text goes through expert and editorial review, the figures are verified against the sources cited in the article, and we hold editorial responsibility for the published content. If you spot an inaccuracy, let us know.

When it pays to hand 3D modelling and print optimisation to a specialist