Motorized Theatrical Spotlight With Axial Control (Sub $100!)

The movement of spotlights is controlled manually, usually by an individual always standing behind the spotlight. This can be a demanding task as the individual needs to be attentive to the light cues and be precise in the direction and intensity of the light. This project aims to solve this issue by creating an easy-to-use moving head theatrical spotlight. This will be a small-scale, instructional-use model that will be controlled by a remote.

Below are the supplies needed for this project. Links to suggested parts are provided for your convenience.

Tools:

• Dremel
• Saw
• Engineers square
• Phillips head screw driver (Sizes #1 and 00)
• Drill
• Calipers for easy measuring/marking (A tape measure is a suitable alternative)
• Laptop for programming

Materials:

• Pack of 1" wood screws
• 2x 1/8" screws
• 1 piece of 1/8" x 4' x 4' plywood
• 1 piece of 3/4" x 6" x 1' of lumber
• 1 2" diameter metal ring 0.56" height (Or other similar object)
• 2x FS90R Servo motors
• 4x PTS645SL50-2LFS Push buttons
• 4x 10k ohm Resistors
• Battery Pack
• 1x LED flash Light
• 1x 8 oz. bottle of Titebond II wood glue
• 1x Arduino Uno

Start by cutting the 1/8" thick piece of wood for the walls, top, and base of the enclosure. The enclosure is made of 6 pieces of wood. Below are the dimensions for each cut:

Top and bottom: 6" x 6"

Front and back sides: 5.75" x 2.75"

Left and right sides: 6" x 2.75"

Next, cut the 3/4" thick piece of wood to make the inner supports for the enclosure and armature. This takes 8 pieces of wood. Below are the dimensions for each cut:

4 pieces: 5.75" x 0.75"

2 pieces: 3.5" x 0.75"

Armature base: 2.35" x 2.625"

Armature arm: 1.75" x 5.275"

• To start, we are going to take 1 of our 6" x 6" pieces of wood. Using wood glue, place 2x 5.75" x 3/4" and 2x 3.5" x 3/4" inner supports an 1/8" away from the surrounding edges as shown in the first picture. On the bottom of this assembled part, screw 2x 1" wood screws in each of the inner supports. This completes the base of the enclosure.

• Repeat the previous process with the last 6" x 6" piece of wood, placing the remaining 5.75" x 3/4" inner supports as shown in the first picture. On the top of this part, make a hole following the dimensions in picture 2. Doing this completes the top of the enclosure.

• Attach the front and back sides of the enclosure by securing each side with 2x wood screws (both along bottom edge of wall) into the inner supports. Attach the left and right sides of the enclosure by securing each side with 1 wood screw (along bottom edge of wall) into the inner supports.

• The left and right side walls are designed to be easily removable. Additionally, the top can easily slide in and out of the enclosure when either of the left or right side walls is not up to allow for easy access to the inside of the enclosure.

• Mount the servo in the hole made on the top as shown in picture 3 and add the metal ring as shown in picture 4. This completes the enclosure.

To construct the armature, use the pieces of wood for the armature base and armature arm.

• Attach the circular motor attachment to the bottom of the armature base using 2 screws as shown in picture 1.

• Bore a hole in the armature arm (dimensions given in picture 2) in order to fit the second servo motor.

• Screw 1x 1" wood screw to connect the armature base and arm as shown in picture 3.

• Fit the servo in the hole you just created as shown in picture 4. Additionally, used the supplied attachment shown in the same picture.

• Use duct tape to secure the flashlight to the servo attachment as shown in picture 5.

To join the armature to the enclosure, mate the servo attachment on the armature to the servo on the base

You should wire all the components together according to the wiring diagram. The Arduino is powered by the battery pack which supplies 5V to the microcontroller and powers the whole system. Make sure you have GND and 5V connections taken from the Arduino to the breadboard and to both of the servo motors.

Before you move on, make sure you have the Arduino IDE software downloaded on your laptop or PC. It is free to download and can be found here - https://www.arduino.cc/en/software. Once the software is downloaded, connect your ArduinoUno to your laptop or PC to upload the program. We’ve included the code file here. Download and save it in a folder.

Click on File -> Open and select the downloaded code file. This is what your code is supposed to look like as you open it up on the Arduino Software. Go to Sketch -> Include Library and make sure a library named 'Servo' is listed. Go to Tools -> Board and select Arduino Uno. In Tools -> Port, check if the correct COM pin is selected. It should look something like this.

Text after “//” are comments that don’t affect the code but provide explanations for the code. It makes it easier to detect certain parts of the code and understand what the function of a line is.

The testing process for the Moving Head Theatrical Spotlight system involves the analysis of 3 major sub-systems. First, the connection between the remote and the spotlight. Second, the resolution of response provided by the servos. And lastly, the range of motion of the moving head theatrical spotlight.

The testing process begins by making the connections depicted in the wiring diagram in Step 5.

Once the connections are made, power is to be supplied to the Arduino via the laptop used for coding. The code should then be uploaded to the Arduino which will be indicated by the momentary blinking of the TX/RX pins. After the uploading process, the battery pack can be used to power the Arduino. The laptop can also now be disconnected. Once the code is uploaded, the servos should move to their initially programmed positions.

To test the connection between the remote and the spotlight, press the left most button on the remote. This should cause the flashlight to twitch in the anticlockwise direction. By pressing the button second from the left, the flashlight should now twitch in the clockwise direction. By pressing the right most button, the x-axis stepper (attached to the base) should rotate in the clockwise direction. Lastly, by pressing the button second from the right, the base should now rotate in the anticlockwise direction. Once this testing is complete, a successful connection between the remote and spotlight has been established.

To test the resolution of response, hold the right most button down until the stepper stops responding. Now set a stopwatch as you press the button second from the right, causing the base to rotate. Stop the timer when the base stops rotating and record the time taken. This value should be under 3 seconds and over 2 seconds to ensure, fast but not rapid response. Repeat the above steps for the other two buttons (left, and second from the left).

Lastly, to test the system's range of motion, hold the right most button down until the stepper stops responding. Using visual inspection, record the position of the base stepper. Now, press the button second from the right until the motor rotates and stops again. Again, using visual inspection, assure that the base motor has rotated approximately 180 degrees. Repeat the above steps for the flashlight using the other two buttons (left, and second from the left).

[1] “Stepper Motors: Types, uses and working principle: Article: Mps,” Stepper Motors: Types, Uses and Working Principle | Article | MPS. [Online]. Available: https://www.monolithicpower.com/stepper-motors-basics-types-uses#:~:text=The%20basic%20working%20principle%20of,rotor%20aligns%20with%20this%20field.&text=When%20coil%20B%20is%20energized,with%20the%20new%20magnetic%20field. [Accessed: 26-Jan-2022].

[2] G. Baluta, “Microstepping mode for Stepper Motor Control,” IEEE Xplore, 07-Jul-2007. [Online]. Available: https://ieeexplore.ieee.org/abstract/document/4292799/. [Accessed: 25-Jan-2022].

[3] Design of novel LED spotlight controller with Dual Remote Control--《journal of Zhejiang University of Science and technology》2012年06期. [Online]. Available: https://en.cnki.com.cn/Article_en/CJFDTotal-YYGC201206005.htm. [Accessed: 25-Jan-2022].

[4] J.-bum W. KAIST, J.-bum Woo, Kaist, Y.-kyung L. KAIST, Y.-kyung Lim, B. Y. University, M. Research, C. M. University, U. of Calgary, and O. M. V. A. Metrics, “Contact-and-connect: Designing new pairing interface for short distance wireless devices,” Contact-and-connect | CHI '09 Extended Abstracts on Human Factors in Computing Systems, 01-Apr-2009. [Online]. Available: https://dl.acm.org/doi/abs/10.1145/1520340.1520550. [Accessed: 25-Jan-2022].

[5] H. Heimbach, A. Klein, A. Lin, M. Lu, and V. Zhuang, “Developing Theatrical Lighting Control with Arduino,” Rutgers School of Engineering, 23-Jul-2015. [Online]. Available: https://soe.rutgers.edu/sites/default/files/imce/pdfs/gset-2014/GSET2015-DevelopingTheatrical.pdf. [Accessed: 25-Jan-2022].

[6] N. *, “The importance of stage lighting,” American Audio Visual, 06-Oct-2019. [Online]. Available: https://www.americanaudiovisual.com/news/importance-stage-lighting/. [Accessed: 26-Jan-2022].

[7] F. Neluswi and R. Foss, “Control of a theater light using the Microsoft Kinect for windows,” Academia.edu, 11-Apr-2017. [Online]. Available: https://www.academia.edu/32385103/Control_of_a_theater_light_using_the_Microsoft_Kinect_for_Windows. [Accessed: 25-Jan-2022].

[8] Q. Guo, S. Bai, Y. Dong, and N. Bao, “The automatic tracking system of near stage lighting,” in 2016 IEEE Information Technology, Networking, Electronic and Automation Control Conference, Chongqing, China, May 2016, pp. 87–90. doi: 10.1109/ITNEC.2016.7560325.

[9] R. Sayer, Rob SayerRob Sayer HND PGDip FHEA is a Senior Lecturer in Technical Theatre Production, A. Mead, D. Cook, Charlie, Rafael, Michael, J. II, DuncanM, linlay Dodin, and Djvex, “Inside a moving head – primer: - stage lighting tutorials, information and how to,” On Stage Lighting, 04-Sep-2008. [Online]. Available: https://www.onstagelighting.co.uk/intelligent-lighting/inside-moving-head/. [Accessed: 24-Jan-2022].

[10] J. Beumer, “Color and light,” Dramatics Magazine Online, 20-Nov-2020. [Online]. Available: https://dramatics.org/color-and-light/. [Accessed: 24-Jan-2022].

[11] C.-S. Wu, K.-Y. Chen, X.-H. Lee, S.-K. Lin, C.-C. Sun, J.-Y. Cai, T.-H. Yang, and Y.-W. Yu, “Design of an LED spot light system with a projection distance of 10 km,” Crystals, vol. 9, no. 10, p. 524, 2019.

[12] H. C. Box, “Stands and rigging,” Set Lighting Technician's Handbook, pp. 71–90, 2010.

[13] B. P. & M. Dahl, “A guide to moving lights,” Back to Shopping. [Online]. Available: https://www.usedlighting.com/lounge/guide-to-moving-lights. [Accessed: 12-Feb-2022].

[14] “G·Spot,” Standard. [Online]. Available: https://sgmlight.com/products/g%C2%B7spot. [Accessed: 12-Feb-2022].

[15] Hqt, “Moving head light: Buyers guide 2021,” VLTG, 08-May-2021. [Online]. Available: https://vltglight.com/moving-head-light-buyers-guide-2021/. [Accessed: 12-Feb-2022].

[16] “100 Kleenex Box covers ideas in 2022: Kleenex Box cover, tissue box covers, Kleenex Box,” Pinterest, 28-Jan-2022. [Online]. Available: https://www.pinterest.com/kathycoupon/kleenex-box-covers/. [Accessed: 12-Feb-2022].

[17] How to power a project. [Online]. Available: https://learn.sparkfun.com/tutorials/how-to-power-a-project/all. [Accessed: 12-Feb-2022].