Yarn Holder

I was initially inspired to make this mainly because I was frustrated with two things: (1) my yarn ball rolling away while I was trying to crochet (2) always needing yarn scraps seemingly right after I decided to get rid of them. 

I ended up making a stackable design that included a yarn ball holder (for keeping yarn from rolling away while crocheting) and a scrap storing container (for keeping old yarn scraps to use in future projects). The yarn ball holder shape was generated procedurally in Houdini and then 3D printed out of ABS, and the scrap container was casted from plaster (in a silicone mold I made). I also used yarn scraps as an additive to the plaster to reduce the total amount of plaster needed. I finished the entire product with lavender spray paint.

Overall, I’m very happy with how it turned out! I use it whenever I crochet :D

Stacked form

Open container

Yarn additive in the plaster

Sustainable Design

When researching sustainable design, I also came across an article about generative design and thought it was a really cool intersection of product design and my interest in procedural art. A yarn ball holder seemed like a good product I could explore this with. I also thought creating a dedicated space for storing scraps would be a great way to encourage more sustainable crafting for myself and others. I had recently learned that polyfill is pretty bad for the environment (apparently it's petroleum-based and very energy intensive to make), so I thought that storing scraps could help me (and other crafters) save alternative stuffing material too. Another part of sustainable design I learned about when doing my research was how people designed products to have alternative uses to extend their life cycles. The yarn ball/scrap holder appealed to me because I was able to design it so these pieces could be later reused. 

Modeling and Fabrication

I first modeled the bottom yarn ball holder using a procedural technique in Houdini as well as a decorative mesh to add a pattern to the lid (to try and make the whole piece more visually cohesive by repeating the pattern). 

Then I exported those as stl files to Rhino, where I modeled the top yarn scrap holder cup and lid. I then used those to make a mold, and then a mold of the mold in Rhino (for the cup and lid). I just 3D printed the yarn ball holder (generative design part) because it would be very difficult to cast that shape. 

I 3D printed the mold of the mold, and then cast silicone (dragon skin 30) into it to make the mold (very meta I know). I then cast plaster with yarn scrap additives into the silicone mold to get the final cup and lid. I made a few mistakes with the plaster casting part (overpoured the mold) so I had to sand and saw it down to get rid of the extra plaster. 

I was a little disappointed that the yarn additive didn’t show up as much as I hoped, so the raw plaster (which I didn’t add color to because I hoped the yarn would pop better) just looked a little plain and unfinished. To remedy this, I decided to spray paint the whole thing (purple spray paint with glossy varnish), using masking tape to leave some of the plaster exposed so you could still see some of the yarn scraps. This helped tie together the plaster and 3D printed parts, and I think it really made the whole thing look more polished!

If I were to do this again…

If I were to do this again, there are two big things I would change. First, the goal of generative design is to minimize material usage, but unfortunately even though my generative design had lots of holes (that theoretically wouldn’t need material) it still needed a lot of support material because of the steep overhangs. I redesigned this part in Houdini using a different algorithm that should require less. I didn’t reprint it because I didn’t want to waste material, but here is a picture of the proof of concept. You can see that because the algorithm “grows” upwards most of the plastic would be supported by printed material under it and require less support material. 

The other big thing I would change would be the way I created the mold for my cup. This was my first time mold making, so I made a lot of mistakes which both made the mold really difficult to use (to get the silicone out of the 3D print I needed to use a bandsaw and power drill, among other things :/) and also wasted material. If I did it again, I would make the mold a three part mold that was cylindrical (rather than the one part box shaped mold I made).

Redesigned yarn holder