What we are making: a real part for your project — a stand, a
bracket or a label — designed around something you measured yourself.
The idea
A part that is not measured is decoration. A part that is measured holds your sensor
at the right height, or clips onto your box, or stands your project up so a visitor can see
it.
So today starts with a ruler, not a screen.
⚠ Careful
The single most common mistake in this session is designing something beautiful that does not fit anything. Measure first. Draw second.
Pick one
A sensor stand — holds your ultrasonic or light sensor at a fixed height, pointing the right way.
A phone-sized stand for your whole project, so it sits at an angle on the exhibition table.
A name plate for your team, with your project's name raised on the front.
A cable tidy — a small clip that holds your wires so they cannot be pulled out.
A button cap — a bigger, nicer top that presses your tiny pushbutton.
⚠ Careful
Keep it under 60 mm in every direction. A big part takes hours to print, and there are 24 teams sharing one machine.
Do it — measure first
Take the thing your part has to fit — the sensor, the board, the button.
Measure it with a ruler, in millimetres. Width, depth, height.
Write the three numbers in your notebook. Not on a scrap of paper.
Draw the part you want on paper, with those numbers written on it.
Show the drawing to your teacher before you open Tinkercad.
The one rule about holes
Printed plastic spreads a little as it cools, so a hole always comes out slightly smaller
than you drew it.
Draw the hole bigger than the thing going in it. About half a millimetre.
💡 Tip
If your sensor is 16 mm wide, draw the slot 16.5 mm. If it still does not fit, go to 17. Two prints is normal. Getting it right first time is luck.
Do it — build it
Start with one box, at the outside size of your part.
Add the holes and slots as Hole shapes, using your measured numbers plus 0.5 mm.
Group everything.
Spin it round and look underneath. Is anything floating in mid-air with nothing holding it?
Check the size one more time, then save with your team name in the title.
📷
images/l1-e2-measured-part.png
Screenshot: a finished sensor stand in Tinkercad with the number boxes showing the measured sizes
What you see
Why
What to do
A part of it floats in mid-air
The printer cannot print onto nothing.
Everything must sit on the bed or on something below it.
It is thinner than 2 mm somewhere
Thin walls snap.
Nothing thinner than 2 mm. Thicker if it holds weight.
The hole is exactly the measured size
It will not fit.
Add 0.5 mm.
It is bigger than 60 mm
Too long to print with 24 teams waiting.
Make it smaller.
Hand it in
Your teacher collects the designs at the end of the session and prints them before next week.
Anything handed in late prints late.
Challenge optional — only if you finish early
Add your team name to the part, raised 1 mm off the surface.
Make one part that cannot possibly print, and be able to say why.