Exploring Crochet Buddy in Onshape
Prototyping with Computer Aided Design (CAD)
The Novel Coronavirus Pandemic has caused a large increase in the number of people picking up crafting in order to fend off the boredom of spending an above average amount of time indoors while sheltering in place. Personally, I picked up crochet as a pandemic hobby. The idea for Crochet Buddy stemmed off of my own struggles with crochet, namely: counting stitches, and maintaining consistent tensions when pulling yarn.
After creating the Analog Prototype for Crochet Buddy, which tested Crochet Buddy’s ergonomic handle design and the placement of the stitch counting camera, it was time to move to Onshape to create a 3D model of Crochet Buddy.
DESIGN
The Crochet Buddy is a fairly simple IoT device with a large impact on those who crochet. The physical device has three main components: an ergonomic handle, a camera facing the crochet hook’s neck, which counts the number of stitches and tracks which type of stitches are being made using a machine learning algorithm. The hook also has a pressure sensitive hook, which tracks the amount of force exerted each time the user pulls for the stitch. The hook will also vibrate when the user should stop pulling on the stitch, thus enforcing a consistent pull, making the yarn-craft more consistent. The physical Crochet Buddy hook attaches to a smartphone application, which helps to enhance the users experience with statistics, pattern integration, and live feedback on your crochet as you go!
PROTOTYPE
The 3D model of Crochet Buddy was made in Onshape: a collaborative CAD modeling program. I began the model as a sketch the front plane. This sketch contained a half view of the side profile of Crochet Buddy’s main form. As you can see, the sketch captures the rounded features of crochet buddy which make it more comfortable to use.
Next, I use the revolve feature for the above sketch, to create the base for Crochet Buddy. this lead to a very simple three-dimensional figure that works as the base for Crochet Buddy.
Once the main 3D form for Crochet Buddy was completed, I created a new sketch, again on the front plane. These sketches are on the same plane to ensure that the sketches overlap and can actually be used for extrudes.
In order to create the cutout that makes up the hook for Crochet Buddy, I used an extrude cut. The extrude cut took the material from the triangle that I had sketched away from the hook. The more angular slanted nature of the cutout for Crochet Buddy is based off of the angular style of Susan Bates crochet hooks, which are objectively the easiest to work with. Most others are too rounded, which makes it difficult to capture the loops that are being pulled through to create a stitch.
For the third time, I created a sketch on the front plane. This time, it was nestled against the thick grip section of the handle, on top of the beginning of the hook. This is the ideal placement because it is out of the way for the user, and it has a pretty solid view down the neck of the hook, which is the vantage point used for counting and tracking stitches.
To create the camera housing, based off of the initial sketch, I used an extrude on the square. I extruded both to the left and to the right with the sketch on the front plane as my “center point.” This allowed me to make the camera housing evenly centered on the hook so that the camera would have the clearest view down the hook’s neck.
Finally, to make the the 3D model more aesthetically pleasing and appear to be more realistic, I used the appearance feature of Onshape to apply a blue color to the hook part of Crochet Buddy. This blue color mimics the standard color for 5mm crochet hooks.
ANALYSIS
Because I’ve taken classes on CAD modeling before, I am fairly content with the decisions that I made to create the 3D model for Crochet Buddy. The 3D model created in Onshape resembles my analog model very nicely. The only real downfall of my prototype is that it is not fully constrained. But, as you can see, the dimensions of the model appear to be correct.
Overall, I am incredibly proud of the 3D model for Crochet Buddy. but there are definitely still areas for improvement. In the future, I would probably do some deeper multi-piece assemblies with constraints in the button interactions. I would include a button that would be used to “indicate the end of the first line of stitches, and any other changes made by the user while working on their piece. This would be located on the trip of the handle. I would also possibly add a long thin button going down the entire length of the hook, that would actually be what was used to gauge the pressure in the pulls for each stitch.
