Introduction: Stop ALICE - Door Barricade for Individuals With Reduced Mobility

The Problem

For individuals who use wheelchairs, it can be difficult to barricade themselves into a room when needed. The goal of this project is to design a device to help individuals who use wheelchairs and/or have reduced arm strength quickly barricade a door to hinder the entry of an active shooter or any unwanted individual.

Competitor Analysis

Overall cons of existing devices on the market:

  • Attach too high or low to doors without a way to access them, violating fire codes.
  • The only function for one specific type of door without the ability to be adjusted.
  • Permanent installation required.
  • The device may not work on a variety of different surfaces.
  • The device may not be usable with only one hand.
  • The device may take too long to set up in a time of need.


After meeting with our client, our group was guided towards creating a device that would have a wedge with a stick extending from it, allowing the user to jam the device into the door with assistance from the foot of the wheelchair. Our group built off of the client’s idea and continued to edit it until it was able to become a functional prototype.


Step 1: 3D-Print the Wedge/Handle Sides/Handle Body


  • Handle Side (x2)
  • Wedge (x1)
  • Rotating Handle Assembly (x1)

Modify the print settings as needed for your printer.

Step 2: Prep the Materials

PVC: Pipe Body and Handle Body

Using the saw, cut a 5-foot segment off of the PVC. Next, cut a 4" segment off of the PVC. Sand the ends flat using the sandpaper/file to reduce the risk of injury.

Nylon Paracord: Door Handle Loop

Using the scissors, cut off a 2-foot segment of Nylon Paracord. Seal the ends by heating over a flame, or gluing the strands together.

WARNING: Do not use super glue to seal the paracord. This will result in a highly exothermic reaction that may cause the paracord to combust.

Dycem: Wedge Liner for Hard Floors

On a sacrificial surface at least 0.5" thick, place the 3D-printed wedge on the dycem. Cut the dycem exactly around the wedge border with an X-Acto knife. Use super glue to fix the dycem to the bottom of the wedge.

Step 3: Assemble the Handle

Insert the end of handle sides into the large rectangular slot on the handle connector. Push the 4" PVC through the two concentric circles to create the handle of the device. As needed, use synthetic grease to loosen the fit, the sandpaper/file to widen the hole, or adhesive to fasten the connections if the hole is too large. Reference the image above if needed.

Step 4: Assemble the Body of the Device

Push the pipe body into one end of the adjustable pipe fitting. Push the cylindrical piece at the end of the handle into the other end. If the pieces do not fit, apply a dab of synthetic grease to the contact areas and try again. If this doesn't work, sand down the 3D-printed part with sandpaper/file until it fits. See the picture for reference, if needed.

Step 5: Fasten Nylon Loop to the Bar

Fasten the section of rope around the bar with a clove hitch knot. Try to keep an equal amount of rope on both sides of the knot. Then, tie an overhand loop using the two free ends of the rope, leaving a loop large enough to fit over any doorknob.

Step 6: Use

Wedge on a Stick

Grab the device from the area that it is being stored. Hold onto the handle of the device as you approach the door of the room that you wish to barricade. Once the bottom of the wedge is near the bottom of the door, insert the wedge between the bottom of the door and the floor. Using the handle, push the wedge in as far as possible to secure the device into place. Once secure, move away from the device and protect yourself. See the attached video for reference.

Over-the-Door Barricade

Grab the device from the area that it is being stored. Secure the open paracord loop around the door handle. The device should hang so that both sides of the PVC pipe are covering the door. If necessary, adjust the device. Once secure, move away from the device and protect yourself. See the attached video for reference.


The device should not be used by children- the 3D printed wedge has sharp edges, and as with any lock, there is a danger of the child trapping themselves in the room.

Do not use super glue on the paracord for any reason. This could cause a dangerous exothermic chemical reaction which could result in combustion of the paracord.

Care and Maintenance

To clean the wedge attachment that has Dycem on the bottom, wash the Dycem with soap and then rinse the bottom of the wedge with warm water.

The device can be easily stored next to the door.

Step 7: Improvements and Extension Projects

In the future, we would like to make the rod of the device out of aluminum instead of the PVC pipe. The aluminum adds more strength while not compromising the lightweight of the entire device. Additionally, we would like to create different attachments for the wedge to allow each wedge to be targeted to work better for a specific material of the floor. Currently, we have the wedge with a Dycem bottom that allows for a stronger grip on hardwood surfaces. We plan to create a wedge with spikes extruding from the base to allow for more grip on a carpeted surface. Another attachment we would like to make is a washable wedge. Additionally, it would be greatly beneficial to add a metal tip to the wedge. Lastly, we would like to create a groove in the rod to allow the paracord to sit more comfortably and tightly, helping to prevent the paracord from slipping down the rod in the device.

Step 8: Resources and References


ALICE Active Shooter Training: Schedule Active Shooter Training & Preparedness Solutions for Schools, Law Enforcement & Organizations. (n.d.). Retrieved from Ox8BtNKddXjvSWKLThJ5uexlkYIbkb4gEAxmHOCtw1U5TnSg2MaAoZxEALw_wcB

Bell, R. (2019, June 18). Why Security Professionals Oppose Classroom Door Barricades. Retrieved from

Bolo Stick School Door Lockdown Device. (n.d.). Retrieved from

Door Security Devices For Schools & Home. (2018). Retrieved from

Master Lock. (n.d.). Master Lock 265D Door Security Bar, White. Retrieved April 2020, from

Nass, D. (2020, January 21). Gun Deaths Inched Up in 2019. Retrieved from

Nightlock® LOCKDOWN - Door Barricade for Schools & Office. (n.d.). Retrieved from

SABRE. (n.d.). SABRE HS-DSA Wedge Door Stop Security Alarm with 120 dB Siren --- Great for Home, Travel, Apartment or Dorm. Retrieved April 2020, from

W.W. Grainger, Inc. (2020). Deadlatch Paddle, RH, Satin Aluminum. Retrieved from