Written by: Enrique Garcia, Application Engineer
A couple of weeks ago my cousin approached me about his son’s new obsession for Spider-Man. Apparently, my nephew had been obsessing about having his own pair of web-shooters for some time and wanted to know if I could help. I was happy to take on the challenge in making some web-shooters and quickly started to do some research on what I would want to include in my design for this new and fun project.
After getting some ideas online from what other people had already designed in the cosplay scene and from the original comic source material, I immediately opened SOLIDWORKS and started to brainstorm.
From what I had seen with other 3D printed designs on the internet, the trigger and main cuff portion of the web-shooter had been printed together as one solid piece.
In designing a web-shooter for a 5-year-old, you don’t need to be a rocket scientist to see that this design choice would not do. One over-powered Spidey punch to the living room couch would mean instant part failure and back to re-printing a whole new web-shooter for your nephew. Since I had already started designing in SOLIDWORKS, I could easily spot-check this by performing a quick FEA simulation to confirm where the stress concentration would be.
This literally took 2 minutes to check and, although overkill for this design, it may save you from additional costly CAD time as a redesign on other less obvious geometries.
So now that I confirmed that I needed to modularize my design into a number of individual pieces, I decided to go with a Master Model Technique in my design so I could have full control of the clearances on each piece at the part level. In the end, I planned to have an upper and lower cuff, a trigger piece and a web cartridge piece all living together in one design.
I started designing the cuff and created a cavity for the trigger part to snap-fit into. I then began designing the trigger portion. To try to ensure that the pieces would fit together in real-life, I used the Offset Entities utility while sketching the trigger piece to make sure that there was enough clearance between my cut-out geometry and the trigger piece so that I could account for the probable size variance from 3D printing process.
I then got some measurements from my nephew’s wrist and fine-tuned the size of the cuff clearance. I also was thinking of how I wanted to secure the cuff and decided to use standard Velcro to secure the cuff pieces around his writs. I created some inner wings on the design to both hold the wrist centered on the cuff and to act as a securing surface for the Velcro. I used the Measure tool in SOLIDWORKS to double-check my clearance after the design was done. I had a clearance of about 1.5in, just enough clearance for his little wrist to slip though!
Lastly, I saved out all the generated pieces of the design by right-clicking on each solid body and choosing “Insert into New Part.”
This allows us to manage each individual piece of the model as its own separate part file. The benefit to creating parts in this way is that it allows us the advantage to have any geometry change done at the original parent part be automatically pushed down to its child so there are no redundant design changes on multiple files; it all can be done at one time.
After all the pieces were saved and organized into STL files, I began to print the design.
After some cleanup and Velcro application I ended up with the below:
I had some small magnets left over from the Moana necklace project I did a few months ago and added some to hold the web cartridges on the cuff so they can be replaceable.
My wife and I brought the finished web-shooters to my nephew’s house and he loved them!!!