Skill Builder – Digital Model Building Overview

Digital Machines - A practical overview

Contour model - 1:1000 - 900x600x50mm

FDM printer ★

It is a rather large model. It would have to be split into multiple parts
There are many flat parts which can easily be represented with sheet material
It would take a long time to print
If one is working with a 2D file would have to be modelled in 3d in a modelling software

Zund Cutter ★★★★

Layers could easily be produced from sheet material
The file required for cutting can be produced in 2D
No burn marks
May struggles with some of the tight details
Would have to be made from card

Laser Cutter ★★★★★

Layers can easily be produced from sheet material
One could easily work in 2d to produce the cut files
Has burnt edges.
Would be able to cut all of the tight corners and details
Could be made from Card, Airplane ply, wood Veneer or Acrylic

Manual Method (Cardboard and a knife) ★

It would take an extremely long time to produce something of this complexity by hand
Would require a massive amount of skill and patience.
Is possible but not recommended if there are digital cutters available.

Landscape model 1:2000 - 350x350x130mm

FDM Printer ★★★★

Some complex 3-dimensional geometry with double curvature, which makes sense to 3D print.
The 3D model would have to be split in 4 pieces which could work. (Only 2 split lines)
The ‘spiral vase’ method could be used to reduce time

Zünd Cutter ★

The form is too organic and is made up of mostly double curved surfaces. Would be make very little sense to produce this on the Zünd.
Would only make sense to use the cut pieces to assist with another manual method in clay by creating templates or an internal armature.

Laser Cutter ★

The form is too organic and is made up of mostly double curved surfaces. Would be make very little sense to produce this on the laser.
Would only make sense to use the cut pieces to assist with another manual method in clay by creating templates or an internal armature.

Manual Method (Clay sculpting) ★★★

If perfect precision and accuracy isn’t of high importance, then this could be a very quick and effective solution.
Some templates or internal structure could be used to help by giving some more accuracy to the model.
A nice idea would be to produce the negative and pour in plaster for a more permanent model.

Small Context building 1:500 - 192x118x48mm

FDM printer ★★★★

FDM printers perform rather well producing small box like shapes
I would take a couple of hours to pint but a rather minimal amount of setup time
Could be clad in a thin material afterward or spray finished

Zund Cutter ★★

Would have to consider the construction method and redraw in 2D before cutting.
Requires some assembly

Laser Cutter ★★

Would have to consider the construction method and redraw in 2D before cutting.
Requires some assembly
Would have burnt edges

Manual method (Bandsaw and Disc sander) ★★★★

Most material options
Easier to sand the individual pieces before assembly. Would be able to achieve a very high-quality finish
Could be clad in paper or card afterwards.

Facade 1:50 - 252x324x8mm

FDM-Printer ★

Not ideal for large flat pieces as it’s prone to warping.
Not the nicest quality finish for something of that size.
Too large for the printer to be printed in one piece.

Zünd Cutter ★★★★★

Would work very well as the elements could be broken down into layers and stacked.

Laser Cutter ★★★★★

Would work very well as the elements could be broken down into layers and stacked.

Manual method (cardboard and Knife) ★★

Would take rather a lot of time
If one has access to a digital cutter, it makes little sense to do this by hand and there are parts with internal cut-outs for the windows.
The strips under the windows however could quite easily be produced on the guillotine.

Structural truss 1:200 500 x 40 x 35mm

FDM printer ★★

Structure not too suitable for FDM printing as the profiles are rather thin. Would work for SLS or SLA but would be very expensive to produce at this scale.
Too large to fit on the 3d printers at the Raplab
As these parts could easily be produced on a digital cutter there is no reason to print these

Zund Cutter ★★

Would maybe struggle a bit with the small details
Would slightly overcut in the corners making them very weak

Laser Cutter ★★★★★

The laser would have no problem replicating something with these intricacies
There would be some assembly required

Manual method ★★ (wooden sticks)

Would take a lot of time and effort to produce something rather fragile.

01/02/202306/04/2023

Learning Spaces FS23

Teaching Team

Blanca Guardelegui
Charlotte Schaeben
Alessandro Tellini
Christian Egli
Henry Welch

Students

Kitchen-Bench
Eugènie Mazerand
Tommaso Delco @tommydelco
Alexej Rubin

Kiosk
Jakob Schaefermeyer
Viviane von Gunten
Constantin Ferst @_const.i

Coat hanger
Tejwani Aanchal @aanchal28t
Daniel Lopes

Sofa
Ayumi Unger
Elodie Dietz
Vivienne Weber

30/09/202230/09/2022

1:500 3d-Print

Scale: 1:500
Material: PLA
Machines: Prusa MK3
Software: Fusion360, Prusa Slicer

The Basic Design

One of the principal considerations in 3d-printing architectural models is how to efficiently cut them before slicing. The technique presented here is a simple way to improve speed and success rates while maintaining an acceptable level of detail.

The principal idea is to separate the roof from the main body of the building so that the top acts as a lid. The body can then be hollow, consisting only of a wall, and prints drastically faster than a support-filled part.

Designing models for this sort of printing requires following some guidelines that have to do with the slicer and the diameter of the printer nozzle (typically 0.4mm).

PrusaSlicer gives us the following recommendation under the parameter “vertical shells”:

Recommended object thin wall thickness for layer height 0.20 and 2 lines: 0.86mm, 4 lines: 1.67mm, 6 lines 2.49mm, 8 lines 3.3mm…

The model below was designed following these rules. The outer wall of the building is 1.67mm thick, and the small lip at the top that houses the roof is 0.86mm. All vertical extrusions try to stay within a 0.2mm grid corresponding to the layer height specified for this print. A 0.2mm layer at the bottom of the print for the wall part was introduced to ensure adequate adhesion on the build plate.

The top part was printed conventionally with 20% infill.

The total print time for this model has been reduced by half by applying these simple techniques while drawing the model.

Material

Polylactic Acid (PLA) is a thermosoft plastic polymer material that becomes pliable or moldable at elevated temperatures. The temperature range for 3d-printing is between 200-230°C with a bed temperature of 60°C to avoid warping.

Results

29/09/202229/09/2022

1:500

1:500

Scale: 1:500
Material: PUR Block (Ureol)
Machines: Printer, Bandsaw, Thicknesser, Disc Sander

The Basic Design

1:500 competition models and especially additions to those models are a fairly common topic in architectural model building. Understanding the fundamental principles of planning for such a model brings you a long way and can help to convey your project in the proper context.

The white model is all about volumetric buildings and proportions. This model typology eliminates all other design aspects to give an “objectified” and comparable overview of a project. It is therefore imperative that details are reduced to only show the base volume of the building you want to build.

The first step in making these models is to analyze your essential volume and subdivide it into different parts. In this step, we typically try to round dimensions up or down to the full – or if not otherwise possible – half a millimeter. This facilitates the actual building process and allows using materials with specific thicknesses. This additional planning goes a long way to making your model-building experience more efficient and pleasant.

Material

Various materials can be used to build 1:500 models, ranging from MDF and basswood to plaster or polystyrene. In our example, we used a type of PUR (Polyurethane) block material sold under many brand names worldwide (Ureol, Prolab, Raku-Tool, Renshape, …). Model builders choose the material because of its workability. It is easy to machine, sand, and glue and can take almost any finish.

Raku-Tool has a density of 0.6g / cm3 and a shore hardness of 50-55. It can be used in the coated form as the final model or as the master for silicone forms. Joining two parts is quickly done with super glue, and gaps or imperfections can be filled with acrylic filler.

Technique

Building the model takes only a few simple steps that are repeated until all parts are finished and ready for assembly. We would like to point out that using the 3d-model to derive the surfaces and printing them as a template for producing parts is an essential technique that speeds up model-building and adds precision to your models. At this point, any preparation you’ve made during the modeling phase pays off its dividends. It typically shows in the details if the assembly logic of the model is simple and well understood. We hid some glue lines in the model by separating parts from the main body and covering the potential problem spots.

1. Create a simple 3d-model and subdivide it into parts
2. Cut your material on the bandsaw roughly into the different thicknesses needed for your project
3. Plane the material to the precise dimensions
4. Mount the templates with spray adhesive to your stock
5. Cut your parts to size, leaving a margin of approximately 1mm
6. Finish your parts on the disc sander
7. Assemble your parts according to your 3d-model
! Sand parts and surfaces that are difficult to reach (inside corners) first!
8. Make sure to sand your whole model with 220 grit to remove all marks from the disc sander
9. Finish your model with primer and top coat

07/09/202231/03/2023

Crafting Wood HS22

07/09/202206/01/2025

03 Raplab Course: Casting Workshop

Casting Workshop Introduction

Hello! I am glad you decided to join this course. I’m your course facilitator, Lila.

I will be your guide for this journey. Please contact me at any point if you have questions or concerns by emailing me directly.

We appreciate feedback, so if you notice anything about this course that could help improve your experience, don’t hesitate to mention it.

Introduction

The course “Raplab: Casting Workshop Introduction” introduces the basic usage of the materials and techniques available in the casting workshop and explains the foundations of safe working procedures that we at Raplab follow to conduct our work.

You can enrol in this course only after completing the Raplab safety introduction. This course is the preparation for the in-person introduction. Both must be completed to get access to the casting workshop.

Who is this course for?

This introduction course is for the BA, MA, MAS, and Ph.D. program students and employees of the Department of Architecture ETH Zurich who need access to the casting workshop of the Raplab.

What will I learn?

You will get an overview of the following topics:

Detailed overview of the Raplab casting workshop (CWS) and its materials and machines.
Introduction to the fundamentals of the materials.
Summary of the casting workshop’s processes and machines involved in creating architectural models.

How do I complete the course?

To complete this course, users must complete the Moodle quiz after studying the learning material.
Reading through the content and completing the quiz will take about one hour.

Learning Material

Rapid Architectural Prototyping Laboratory (Raplab), 21. Mai 2015, D-ARCH, Hönggerberg, HIL B 37

07/09/202209/04/2025

04 Raplab Course: Digital Workshop

Digital Workshop Introduction

Hello! I am so glad you decided to join this course. I’m your course facilitator, Henry.

I will be your guide for this journey. Please contact me at any point if you have questions or concerns by emailing me directly.

We appreciate feedback, so if you notice anything about this course that could help improve your experience, don’t hesitate to mention it.

Introduction

This course introduces the basic concepts of each machine available in the digital workshop and explains the foundations of proper working procedures that Raplab follows to conduct its work.

You can enroll in this course only after completing the safety introduction. The course qualifies you to use the digital workshop independently after showing the completed exercise to me.

Who is this course for?

This introduction course is for the BA (3rd semester and above), MA, MAS, and Ph.D. program students and employees of the Department of Architecture ETH Zurich that need access to the digital workshop of the Raplab.

What will I learn?

You will get an overview of the following topics:

Detailed overview of the Raplab digital workshop (DWS) and its machines.
Introduction to the fundamentals of the machinery.
Summary of the materials that can be processed.

How do I complete the course?

To complete this course, users must study all the listed learning material to prepare for the Moodle quiz and independently complete an exercise that demonstrates their proficiency in using the machines.

Reading through the content and completing the quiz will take about two hours. An additional 30 minutes are required to complete the in-person exercise.

Learning Material

07/09/202213/09/2024

02 Raplab Course: Wood Workshop

Wood Workshop Introduction

Hello! I’m so glad you decided to enroll in this course. I’m Christian, your course facilitator.

I will be your guide on this journey. Please email me directly at any point if you have questions or concerns.

We appreciate feedback, so if you notice anything about this course that could help improve your experience, don’t hesitate to mention it.

The Moodle course “Raplab: Wood Workshop Introduction” introduces the basic safety concepts of each machine available in the wood workshop and explains the foundations of safe working procedures that we at Raplab follow to conduct our work.

You can enroll in this course only after completing the safety intro. This Moodle course is the preparation for the in-person introduction. Both must be completed to get access to the wood workshop.

Who is this course for?

This
introduction course is for the BA, MA, MAS, and Ph.D. program students
and employees of the department of architecture ETH Zurich that need
access to the digital workshop of the Raplab.

What will I learn?

You will get an overview of the following topics:

Detailed overview of the Raplab wood workshop (HWS) and its machines.
Introduction to the fundamentals of the machinery.
Summary of the materials that can be processed.
Basic safety rules and best practices related to each machine.

How do I complete the course?

To complete this course, users must complete the Moodle quiz after studying the learning material.
It will take about two hours to read through the content and complete the quiz.

Learning Material

14/04/202214/04/2022

Adhesives

Adhesives For Model Building

This list explains some of the basic types of adhesives commonly used in model and prototype building and should serve as an overview to guide you in the right direction. Please do your research for specific application techniques and safety procedures for chemicals and adhesives before using them. Always work in well ventilated areas and wear your personal protective equipment if necessary.

More information on adhesives can be found on www.materialarchive.ch

PVA Glue

Polyvinyl Acetate Glue is typically sold as white glue and used on various materials – mostly paper and wood. Objects that must be joined permanently need clamping pressure to form an acceptable bond. PVA glue is stronger than wood, meaning that the material will fail before the glue does. The glue is excellent for gluing edges of the cardboard and is fast curing if applied in small amounts. Model builders typically apply PVA glue with a toothpick to the delicate edges of the card to avoid excess moisture and slow curing.

Materials: Wood, MDF, Paper, Cardboard, Leader, Foam Board

Further reading...

CA Glue

Cyanoacrylate Glue is the go-to glue for professional model builders. It typically comes in three types of viscosities. Low viscosity for fixing cracks and applications that rely on capillary action. Medium viscosity for general purposes and low viscosity for applications where the glue needs to fill small gaps. CA glue can be used with a dedicated accelerator to speed up the curing process. For special purposes, the glue can be mixed with talcum powder to form a soft putty for filling and sanding or baking powder to instantly cure the glue and form a hard, durable joint.

Materials: MDF, Wood, PU Block, PS

Further reading...

Contact Adhesive

Contact Adhesives can join a wide variety of different materials. The process typically involves applying the glue to both sides of the joint, waiting for a couple of minutes for the glue to dry, and then pressing the two parts together. The glue is activated by pressure. This technique lends itself to applications where large surfaces must be laminated together and are not used in wood joinery or constructions where edges are joined. Typical applications are laminating some top layer to a substrate like in veneering or for joining foam.

Materials: Laminates, Foam

F urther reading...

PU Glue

Polyurethane Glue is activated by moisture and tends, depending on the type of glue, to expand (foam). The foaming action helps with filling any voids in unregular surfaces and parts. Typical applications range from installing door frames to manufacturing plywood prototypes. PU Glue is a niche product in model building and is primarily used for laminated plywood or difficult glue-up situations.

Materials: Wood, Plywood, Veneer

Further reading...

Dichloromethane

Dichloromethane is a clear, water-like, odorless solvent that can be used to join acrylic glass and polystyrene. It creates an almost clear joint by opening the chemical bond of the plastics to fuse them back together once the solvent is gone. Dichloromethane is extremely toxic and volatile. It should be used sparingly and with caution only in well-ventilated areas. Alternatives to Dichloromethane have specially formulated CA Glues for PMMA that have reduced off-gassing characteristics.

Materials: PMMA, PS

Further reading...

Epoxy

Two-component epoxy glues are in model building most commonly used in the form of 5min epoxies when dissimilar materials like wood and metal need to be joined somehow. Epoxy glues, in general, have a wide variety of applications ranging from boat building and the aviation industry back to the hobby market. Remember that epoxy produces an exothermal reaction during the curing process that can lead to extreme temperatures and even fire. Always mix small batches of epoxy (<100g) and spread excess glue on a flat surface for curing.

Materials: Wood, Aluminium, Composites

Further reading...

Spray Adhesive

Spray Adhesives come in high strength and positional variants. In modelbuilding, the prepositional one is mainly used for gluing paper layouts to parts for cutting and sanding. The high strength or permanent type can be used to clad volumetric models with paper, veneer, or fabric. Besides these two main ones, you can find an assortment of more specialized spray adhesives on the market, for example, for gluing polystyrene or foam.

Materials: Paper, Veneer, Fabric

Hot Glue

Generally speaking, hot glue has a bad reputation among model builders because of its strong association with bricolage. Nothing could be further from the truth – hot glue, applied properly, is fast and clean. Model builders use hot glue for all sorts of applications where water-tight joints must be created, like in mold building and in situations where you have to speed up an assembly process. For example, when you join wood, a drop of hot glue holds the parts together while the PVA glue dries. Not a method employed by fine furniture makers, but a valid way to get things done in the model shop.

Materials: Foamboard, Corrugated cardboard, PMMA, Leather

Further reading...

Silicone

Silicones are available in various formulations that highly depend on the use case. Silicone which is important as glue, comes in the form of caulking and is used in the building industry as an elastic sealant for different materials. In the model building shop, silicone adhesive is used for mold making and joining glass and mirrors. Ensure that the parts that need to be joined are grease-free before applying any silicone and allow for drying overnight for best results.

Materials: Glass, Mirrors

Extrusion

Plaster Extrusions

Scale: Free

Material: Plaster, PMMA, Wood, Shellac

The Basic Design

For this tutorial, a simple profile was chosen as the basis for creating a plaster extrusion that gets assembled into a ring of eight segments.

Having methods and techniques at hand that allow the creation of complex objects is of great importance in model building. It allows the designer to think in different materials and lets him or her express form in a more precise way.

Keep in mind that you will benefit the most from working with this material if you apply your twists and variations to it and do not just follow the examples.

Material

Plaster, properly understood, can be used in different stages of its hardening process. The most common way of working with plaster is, of course, pouring, but carving, sculpting, extruding, and even turning is possible.

The extrusion process takes advantage of the fact that plaster has a gentle curing curve. Freshly mixed, it is too liquid to be of use for extruding the material, and a bit of patience is needed to get to the right consistency where the plaster is almost like cream cheese. In this phase, plaster builds up quickly and can be extruded into nearly any shape.