Model 10: Plotter

I write and paint your idea!

Grade

5 - 7

Time required

2 (up to 8) double hours

Difficulty level

Model: medium to hard, Programming: medium to hard

Model type

mobile device, can be positioned and used individually

Download didactic material

MODEL DESCRIPTION / TASK

The pupils (SuS) plan and realize a plotter that can record routes and thus enable the automated creation of line drawings. A two-axis plotter is built for this purpose, which can be moved in the x and y directions using a worm drive. The plotter can safely move to its start or end position by means of a limit switch for each axis. The travel paths are measured using pulse wheels with 4 pulses per revolution, so that the plotter can be positioned with an accuracy of ¼ revolution.

EVERYDAY USE

The automatic triggering of a process has a strong motivational effect on pupils. The automatic creation of line drawings is quick and easy for everyone to grasp. Two possible additions to the basic task make it possible to
individualization of the topic. The topic could be integrated into pre-vocational orientation with regard to information technology or design professions. Automated printing or drawing (plotting) is used in many areas here. In particular, the sensor-based recording of movements is becoming increasingly important in many areas of production technology, e.g. laser cutting or 3D printing. The two-axis plotter is therefore a very good introduction to automated 3-axis production

Key questions

Where can automatic drawing or cutting be used in everyday life? (Communication)
What functions does the system need to fulfill? (Collaboration)
Under what conditions should the system switch on or off? (critical thinking)
What needs to be considered to ensure that the system can be used with different media (paper, film) and that the system functions as robustly and reliably as possible? (creativity)

Subject reference

Computer sience

Programming basics, time loops, saving variables, comparisons, loops, travel paths

Technology

Stable construction, construction technology, gears, conversion of rotation into linear motion

Physics

Electric motor, change in motion, linear motion

Mathematics

Coordinate system, coordinate geometry, linear functions

Lesson progression

Information and notes

Methodical and didactic tips

Differentiation options

Faster pupils can be given the task of extending or shortening the playing time.

Motivational aspects

Pupils are familiar with grab machines from various locations in everyday life. Perhaps they have already operated such a gripper machine. Being on the “production side” instead of the “operator side” may fill them with pride.

Additional material

If available, pictures of free machines can be presented for the introduction to the topic.
If necessary, drawing media (paper, whiteboard or projection screen).

Building instructions

Circuit diagram

Functions of the model and their technical solutions

Function of the sensors/actuators

Technical solution

Executing a movement in the x-direction

Control of the x-axis motor

Executing a movement in the y-direction

Control of the y-axis motor

Stopping the movement in the x-direction

Evaluating the signals at the limit switch

Stopping the movement in the y-direction

Evaluating the signals on the limit switch

Controlling the movement in x-direction

Evaluating the signals on the rotation counter/button

Controlling the movement in y-direction

Evaluating the signals on the rotation counter/button

Start a drawing

Input of a signal at the On/Off button of the controller

End/emergency stop

Input of a signal at the On/Off button on the controller

Material list

Sensors

Function

1 On/Off button on the Controller

Switching on the plotter
Emergency top of the plotter

2 buttons

Limit switches x- and y-axis

2 buttons

Rotation counter per axis in 90° steps

Actuators