The What

A guard for the nozzle of hot glue guns, capable of significantly reducing surface temperature, allowing for safer usage.

The Why

The initial target audience of this project was the general population of Seven Hills, a community dedicated to helping people with a wide range of disabilities achieve a higher level of independence. While this group was our main target audience, the project can be used by anybody who wants to use a hot glue gun. The tip of an average hot glue gun can reach temperatures of up to 380 degrees Fahrenheit, seriously burning any individuals who may touch it. With our guard, the surface temperature of the hot end is greatly reduced and users can safely touch it for longer periods of time without getting burned.

Requirements

By following the link below or downloading the PDF, you will find the requirements our group set out for this project. The list is organized by requirement type and level. The level of the requirement indicates how important we thought it was that our device met the criteria. Along with our current device is some of other prototypes to show why we decided on going with the final design we chose.

Requirements Google Doc

Competitor Analysis

To ensure that our device is original and improves upon existing products that complete similar objectives, we looked at many different safety measure for hot glue guns. We found that the devices that already exist would not meet many of our criteria for various reasons. To see notes on of all of the devices we researched and our reasoning for why we can improve upon them, follow the link below or download the PDF.

Competitor Analysis Google Doc

Step 1: Gathering Materials and Tools

Bill of Materials Used in Development:

The AdTech Two Temp Hot Glue Gun ($10.40)
- Amazon Page
Smooth-On Silicone Mold OOMOO 30 ($25.49)
- Amazon Page
Wool Thread ($7.99)
- Amazon Page
Thick Rubber Bands

Tools Used:

3D Printer and PLA filament
Plastic Cup and Spoon for Stirring OOMOO

Step 2: 3D Print the Mold for the Guard

Access the attached, ready to print CAD files so that you can print the mold for the guard. Initially, the guard was made specifically for the AdTech Two Temp Hot Glue Gun, so if you plan on making a guard for a different glue gun, minor adjustments may be necessary in order to have the correct dimensions.

Mold Top: https://skfb.ly/6z6rQ
Mold Bottom: https://skfb.ly/6z68q

Step 3: Create the Silicone Mold Mixture

The silicone mixture was created with equal parts of Part A and Part B. One spoon of each Part is sufficient to create a single guard.

Step 4: Pour the OOMOO Mixture Into the Mold

The mixture is then poured from high above the mold, to release any air bubbles that might have been trapped in the silicone. The mixture is poured until the mold is filled to the top. The mold is then closed shut and cures over the following 6 hours. Any excess OOMOO will be removed through vents.

Step 5: WAIT!

The silicone rubber mixture can take a while before it hardens, six hours to be exact. This would be a good time to kick back, relax, and think about how you will change the world with the safer glue gun you are about to have.

Step 6: Creating the Strap

The guard was created to hold on tight to the glue gun and it has a fairly strong grip around the tip while the glue gun is not being used. However, when the glue gun heats up, the guard begins to slide off of the tip which means that it can not really help you out anymore. That is why our group designed a strap to hold the guard in place during use.

Steps:

Cut two strands of thread, we suggest wool as a material because of its natural flame resistance, but other flame and heat retardant materials are fine as well. The strands will need to be 12.5 cm long from guard to rubber band.
Tie a slipknot in each string and tighten the loops around the guard. The guard has been designed with a shallow ridge to hold the thread.
Cut a rubber band into a 6.25 cm section.
Thread the non-slipknot ends of the two threads through the two ends of the rubber band. Poking holes in the rubber band with a thumbtack usually makes it easier than trying to go right through with a needle.
Tie off the two threads, making sure to leave 12.5 cm of thread between the guard and the rubber band.

Step 7: Hot Glue Away!

After following these steps, you are now a proud owner of an innovative hot glue gun protector. Putting the protector on and taking it off is simple, and to make it even easier we have included a video of a member of our crew showing you how it works. It took our group a lot of trial and error and small adjustments to get the right dimensions for our glue gun so we hope that any tweaks you have to make for your specific glue gun are swift and painless.

Step 8: Improvements and Extensions

While the glue gun guard in its current state will be able to protect you if you happen to touch the side of the hot glue gun's hot end, there are still some improvements that could be made. We have included a few possible changes that you could think about making.

Automated Cap: The guard shields you from the majority of the hot end, but the tip is left exposed by design to improve the usability of the device. Our group experimented with many variations of a mechanism that would have a cap which would automatically be lifted off of the glue gun when the trigger was pulled, and would return to cover it when the trigger was released. We were able to build a working cap system, but decided not to include it as it negatively impacted the user's visibility. Depending on how you primarily use your glue gun, the cap system could be a possibility for you. Feel free to contact us if you have any questions about this.

Attachment Method. The guard is currently attached to the glue gun with a wool string and a rubber band as described above. There are many other ways to attach guard, such as connecting the string to a small screw clasp in the back, so feel free to experiment.

Aesthetics: The hardened OOMOO has a dark purple color, which may not necessarily be to your liking. There are a number of tutorials that can found online that show how to change the color of a silicone rubber, so you can make the guard that is a perfect match to your glue gun.