Rebel Engineering


Project Overview

The Cable Combatter is the solution to the frustration caused by cables getting tangled. Fully automated, the Cable Combatter can clean coil cables with the press of a button.  The key to the Cable Combatter is its ability to coil cables in the over under method, a technique of coiling that prevents cables from getting tangled or damaged. It is very common for cable users to wrap cables such as extension cords around the hand and elbow to quickly coil them. Over time, this will cause the cable housing as well as the electric cables inside the housing to twist, eventually pulling the wire leads from the heads of the cable inputs. By laying the cable out in a figure eight pattern and folding the cable on top of itself, the Cable Combatter is able to mechanically achieve the over under method. Until now, the over under technique could only be done by hand, but the Cable Combatter is able to replicate the speed and dexterity of a person.  

Design Inputs

The Cable Combatter was designed with the following design specifications in mind:

  • The project will cost less than $1000
  • It will operate off of a 120V wall outlet.
  • Will coil a cable n the over under method at .1 ft/s.
  • Will be smaller than 4’x4’x4′.
  • Will weigh less than 175lbs.
  • Will function with a 50 foot 1/4″ XLR cable.
  • Will function off of an on/off switch.

Proof Of Concept

The purpose of the proof of concept was to functionally validate the cable coiling mechanism of the Cable Combatter. The design needed to be tested in a way to prove that it coils in the over under method. The only way to properly test the design was to build a prototype and run a cable through it. The prototype is a wooden scale model of the of the final design, and does not utilize any motors or pulleys. Figure 1 shows the CAD model of the  prototype.

Figure 3: Full CAD model of prototype

Figure 1: Full CAD model of prototype

The entire frame was built from wood and screwed together. A 20 inch bike tire rim was also utilized and mounted on rubber caster wheels to allow it to rotate freely. The ABS pipe nozzle was zip tied to two U-bolts and mounted on a piece of wood that was screwed to the center of the bike rim. An oriented strand board was cut and hinged to function as the flipping platform. Figure 2 shows the completed prototype.


Figure 2: Finished prototype of the Cable Combatter

All the moving parts of the prototype will be operated by hand. Testing involved running a 50 foot XLR cable through the prototype and seeing if it can successfully coil in the over under method. Some other testing criteria included how quickly the cable would be coiled and if the nozzle would interfere with the flipping platform.

Design Outputs

The design outputs are intended to show that the project can meet the required inputs. Solidworks models and drawings are displayed to validate the Cable Combatter’s design. A circuit schematic is also included to validate the functions of the motors. The overall design of the Cable Combatter was changed from the proof of concept to better meet the design inputs.


Figure 3: Solidworks model of full assembly.


Figure 4: Circuit Schematic of motors wired to arduino.

Verification and Validation

The Cable Combatter was tested using a 100 foot ¼ inch XLR cable. Testing was conducted by utilizing an Arduino code to power the stepper motors. The code was adjusted until the stepper motors functioned properly and successfully coiled the cable in the over-under method.The testing successfully showed that the Cable Combatter can coil a cable with the flick of a switch.


Most of the fabrication process consisted of steel welding and other metal work. The pieces that were not welded were drilled and bolted together. A heavy amount of electrical wiring was also required to set up the motors. The motors were connected to an arduino with stepper motor drivers. The arduino was then programmed to  activate the motors at different times.


Figure 5: Initial welding of frame.


Figure 6: Welding on the arm and supports.


Figure 7: Post Fabrication.

The Final Prototype

The final prototype successfully coils a XLR cable in the over under method. Simply priming the cable and turning it on will allow the Cable Combatter to coil any length of cable. It does not coil faster than a person however, and future plans including increasing the speed at which it coils. Other future plans include decreasing the weight and making and overall smaller and more mobile design.


Figure 8: Front view of final prototype.


Figure 9: Side view of final prototype.

Meet the Team

(Kellen Mitchell, Johnny Sheerin, Armahn Soltani, Maitland Bell, Luke Fuller)

(Kellen Mitchell, Johnny Sheerin, Armahn Soltani, Maitland Bell, Luke Fuller)

Rebel Engineering consists of five soon to be graduates in Mechanical Engineering at The University of Nevada, Reno. Having similar interests in engineering and love for coiling cables, Rebel Engineering is the optimal group to have taken down the challenge of automating the over under method in a mechanical manner.