1. How to run a 3D modeling and
3D printing workshop for 8-12+ ?
The catapult
1
Co-developed with the help of:
Paris public libraries
Techkids Academy

2. Table of content
Workshop for 8-12 kids
Adapted content for 8-12 years old kids
Workshop for 12+ kids
Adapted content for 12+ years old kids
2

3. Workshop for 8-12

4. 8-12 workshop: become an engineer !
4
Objectives :
Allow kids to discover how to design an object, on their own or within small groups,
Develop kid’s creativity to win a challenge,
How to :
Asking them to design a catapult that can shoot as far as possible,
Scenario :
Day 1 : design a catapult following a plan,
Day 2 : improve it or create your own catapult.
Pre-requisite: an introduction workshop on 3D printing and modeling with 3D Slash,
Note:
-In order to make the workshop more playful, we recommend you to print a demonstration catapult
(the .STL file is provided further in this presentation).

5. Ask kids to model the standard catapult (day1),
and then their own model (day 2)
5
The result once modeled in 3D
Slash
Then let the kids think of improvements of the
standard model to shoot farer, and ask them to model
these improvements in their own catapult
Follow the plan
to build the standard catapult
Day 1
Day 2

6. Sequence steps in a progressive way during
1h30’ (Day 1)
Modeling of the standard catapult
15 min’ - Introduction
5 min’ – Introduction of the objective of the workshop: play it like an engineer and design a catapult
that can shoot as far as possible (standard model on day 1, and a custom one on day 2),
5 min’ – Brainstorm : what is a catapult, what are the components, how does it work ?
5 min’ – Show the modeled and printed object, and explain the first steps to achieve,
1h’ – Follow the plan to model the catapult. Depending on each kid advancement:
Show how to build the second bearing and the launcher,
Finalize the catapult creating a junction between the launcher and the bearings,
15 min’ – Test the demonstration catapult, and explain the objective of day 2.
6

7. Sequence steps in a progressive way during
1h30’ (Day 2)
Improve or create your own catapult
15 min’ – Ask open questions on how to improve the catapult so that it can shoot
farer,
1h – According to each kid advancement and motivation either ask them :
To create their own catapult,
To improve the standard model,
To finish the standard model,
To model something else of their idea,
15 min’ – Ask kids to share the created models explaining why they would shoot
farer.
A best practice in free creation is to ask every now and then to a kid to show quickly what he did –
so that others can benefit and get inspired in their creation.
7

8. Model the catapult
Follow the steps of the starter file:
https://www.3dslash.net/thing.php?hash=1de7246038fea3364d29a1fe42da0fd03
46ba58216ad83d66909ed94ed753cd7&filter=3,0,0,0
Create a junction between the launcher and the bearings:
Make a nick to print the catapult toe (this step is
not necessary to finish the model, but will be
necessary to print it).
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9. Important notice regarding 3D printing
It takes approximately 3 hours to print a catapult. Consequently you will need to
print a demonstration model BEFORE the workshop so that you can show it to the
kids,
The demonstration file to print is available at the following link:
https://www.3dslash.net/thing.php?hash=8d072d461d86c8af0ee091f82970d856fcd528
41184df599a73ae33394c746c2&filter=3,0,0,0
Click on the link and download the .STL file to print it on your printer ; OR print it
online clicking directly on the icon « print » at one of our partners.
Note: this design was carefully though so that you can print it directly without cutting
or reposition/lie down parts of the catapult (except the toe..).
If you have any questions or feedback feel free to contact us at:
jean-marie.laly@3dslash.net
9

10. Workshop for 12+

11. 12+ workshop: become an engineer !
11
Objectives :
Allow kids to discover how to design an object, on their own or within small groups,
Develop kid’s creativity to win a challenge,
How to :
Asking them to design a catapult that can shoot as far as possible,
Scenario :
Day 1 : design a catapult following a plan,
Day 2 : improve it or create your own catapult.
Pre-requisite: an introduction workshop on 3D printing and modeling with 3D Slash,
Notes:
-It is necessary that you install free desktop version of 3D Slash to fulfill this workshop,
-In order to make the workshop more playful, we recommend you to print a demonstration catapult
(the .STL file is provided further in this presentation).

12. Ask kids to model the standard catapult (day1),
and then their own model (day 2)
12
The standard model once
modeled in 3D Slash
Then let the kids think of improvements of the
standard model to shoot farer, and ask them to model
these improvements in their own catapult
Follow the plan to build the catapult with the proper
dimensions (cf next slides of this presentation)
Day 1
Day 2
100 mm
40 mm 10 mm 50 mm
8 mm
56 mm
80 mm
64 mm16 mm
4 mm
16 mm

13. Sequence steps in a progressive way during
1h30’ (Day 1)
Modeling of the standard catapult
15 min’ - Introduction
5 min’ – Introduction of the objective of the workshop : play it like an engineer and design a catapult
that can shoot as far as possible (standard model on day 1, and a custom one on day 2),
5 min’ – Brainstorm : what is a catapult, what are the components, how does it work ?
5 min’ – Show the modeled and printed object, distribute plans, and explain the steps to achieve,
1h00 min’ – For each part of the catapult (there are 5):
5 min’ – Demonstration : show the manipulation to realize ;
5 min’ – Exercise : let kids operate the manipulation,
15 min’ – Test the demonstration catapult, and explain the objective of day 2.
13

14. Sequence steps in a progressive way during
1h30’ (Day 2)
Improve or create your own catapult
15 min’ – Ask open questions on how to improve the catapult so that it can shoot
farer,
1h – According to each kid advancement and motivation ask them:
To create their own catapult,
To improve the standard model,
To finish the standard model,
To model something else of their idea,
15 min’ – Sharing of the created models explaining why they would shoot farer.
A best practice in free creation is to ask every now and then to a kid to show quickly what he did –
so that others can benefit and get inspired in their creation.
14

15. Reproduce the catapult using the plans (1/2)
15
96 mm
8 mm
56 mm 80 mm
64 mm16 mm
4 mm
20 mm
40 mm 8 mm 40 mm 8 mm
16 mm

16. Reproduce the catapult using the plans (2/2)
16
16 mm
8 mm
48 mm
8 mm 16 mm
80 mm
32 mm
20 mm

17. Model the catapult, step 1
Design of a plate
Step 1 : Create a new block sized 128x128x128mm, and sculpt it to get a 96x56x8mm plate (on the green-
red side as showed on the picture).
17
96 mm
56 mm
8 mm

18. Model the catapult, steps 2 and 3
Design of the first bearing
Step 2 : Use the chisel tool to cut the plate at the right dimensions,
Step 3 : Use the drill tool to remove the parts cut with the chisel and obtain the expected bearing.
18
40 mm 8 mm 40 mm 8 mm
16 mm

19. Model the catapult, steps 4 and 5
Copy-paste the bearing :
Step 4 : switch to expert mode,
Step 5 : use the copy/paste function, and move the copied bearing on the blue axis so that there are 32 mm
between the two bearings.
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32 mm
40 mm

20. Model the catapult, steps 6 and 7
Junctions between the two bearings:
Step 6: Create front, back and top junctions using the pulpwood tool,
Step 7 : Create the circular junction of the launcher (4 mm diameter) using the « cylinder » tool.
20
20 mm
4 mm
Note : to make the circular junction, orientate the
cylinder on the blue axis, and select 1/4mm cubes
to fill the cylinder.

21. Model the catapult, steps 8 and 9
Design the launcher :
Step 8 : Use the pulpwood tool to create a 80x6x8 mm plate on the sides of the circular junction,
Step 9 : Design the launcher sculpting the plate.
21
8 mm 6 mm
16 mm
80 mm
64 mm
20 mm

22. Synthesis of the 9 steps
Design of the first bearing:
Step 1 : Create a new block sized 128x128x128mm, and sculpt it to get a 96x56x8mm plate (on the green-red
side as showed on the picture),
Step 2 : Use the chisel tool to cut the plate at the right dimensions,
Step 3 : Use the drill tool to remove the parts cut with the chisel and obtain the expected bearing,
Copy-paste the bearing :
Step 4 : switch to expert mode,
Step 5 : use the copy/paste function, and move the copied bearing on the blue axis so that there are 32 mm
between the two bearings,
Junctions between the two bearings:
Step 6: Create front, back and top junctions using the pulpwood tool,
Step 7 : Create the circular junction of the launcher (4 mm diameter) using the « cylinder » tool,
Design the launcher :
Step 8 : Use the pulpwood tool to create a 80x6x8 mm plate on the sides of the circular junction,
Step 9 : Design the launcher sculpting the plate.
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23. The standard model of the catapult:
https://www.3dslash.net/thing.php?hash=7d25e141f5d4135a7db05176d1a152f8f86c5
f8d6cd786e3a1d1d6161b679ee4&filter=3,0,0,0
Note : this is an « HD » file - add it to your « favorites » and open it on your local app.
Link to the model
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24. Important notice regarding 3D printing
It takes approximately 3 hours to print a catapult. Consequently you will need to
print a demonstration model BEFORE the workshop so that you can show it to the
kids,
The demonstration file to print is available at the following link:
https://www.3dslash.net/thing.php?hash=79eea5ea22aa9b0d94abc1e5387e525f9ebf10
efc2598dc0625482117428e403&filter=3,0,0,0
Click on the link and download the .STL file to print it on your printer ; OR print it
online clicking directly on the icon « print » at one of our partners.
If you have any questions or feedback feel free to contact us at:
jean-marie.laly@3dslash.net
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25. End of the document