Grand Valley State University

Padnos School of Engineering

EGR 450 – Manufacturing Controls

Motion Sketcher

1.0 Project Description

The goal of this project was to upgrade a drawing machine so that it could be displayed in the Keller Engineering Lab as an interactive machine to be used by visitors, students, and professors. The drawing device was built by Grand Valley engineering students last year and our team has made many improvements and additions to it. Bearings and a flexible coupler were added to the mechanics of the device in an effort to reduce the vibration of the pen. A brand new control system was designed including the addition of a wiring panel, new diffuse sensors, and new logic. The system was designed so that it could be used while being exhibited in a display case. The drawing machine is operated by motioning your hand over six different diffuse sensors and a programmable logic controller (PLC) is used along with these inputs to control the motion of the pen.

2.0 Components

The device was designed so that it could be disconnected into three different components. This was done to allow relocating the device to be fast and effortless. The first component of the system is a panel comprised of six sensors that are used by the operator to control the drawing device. The second component is a wiring panel, which contains the circuitry that is used to control the device. The third component of the system is the drawing device, which contains all of the mechanics of the system.

1 – GS Sola Electric 24 Volt Power Supply used to supply power to the following components.

6 – Diffuse Optical Sensors

One sensor to raise/lower the pen.
One sensor to feed the paper.
Two sensors to move the pen horizontally (left/right).
Two sensors to move the pen vertically (up/down).

Solenoid

4 – Limit Switches

Used to prevent over travel of the pen on the horizontal and vertical axes.

6 – Square D 2 Pole 24 Volt Relays

Two relays used for each 12 Volt Dayton motor and two relays for the solenoid.
For the pair of relays used for each motor, one relay was used to turn the motor on and off and a second relay was used to change the direction of the motor.For the pair of relays used for the solenoid, one relay was used to turn the solenoid on and off and a second relay was used to change the direction of the current through the solenoid so that the pen could be raised and lowered.

1 – 12 Volt Car Battery to supply power for the following components.

3 – Motors
1– Buehler Products Inc. 12 Volt DC. Used to feed the paper.
2 – Dayton 12 Volt DC. Used to move the pen horizontally and vertically on the paper.

1 – Allen Bradley PLC (SLC 500 1747-L20C)
1 – 25 Pin Parallel Port Connector

Used to connect the six sensors to the wiring panel.

1 – 16 Pin Connector

Used to connect the components on the drawing device to the wiring panel.

3.0 Circuitry

In an effort to keep the system organized and easy to follow, the hardware was mounted to a panel, the wiring was routed through channels, and each wire was labeled. You can look at the following pictures for information on the Motion Sketcher or click on the foot note to download the picure in AutoCad R14.

Wiring Panel Layout

Wiring Diagram for Inputs/Outputs

Wiring Schematic

4.0 Controls

Diffuse sensors were selected because they were able to detect an input from the user from behind glass. The six sensors are used to feed new paper, raise/lower the pen to draw, and move the pen horizontally and vertically on the paper. RSLogix 500 was used to write the program that is used to control the mechanics of the system. Below is the logic that was run. You can also click on the following link to download the program.

Motionsketch Ladder Logic

5.0 Operating Instructions

1. If the pen is currently lowered, raise the pen by motioning your hand once over pen positioning sensor (lower left sensor).

2. Hold your finger over the paper feed sensor (upper left) until a clean drawing area is achieved.

3. Position the pen to the desired location to begin drawing by holding your finger over the correct sensor (up/right/down/left).

4. Lower the pen by motioning your hand once over the pen-positioning sensor (lower left sensor).

5. Begin drawing by holding your finger(s) over the desired direction of motion (up/right/down/left).