Recycled Vertical Planter

My name is Anders Voss, and this is my submission for the Fall/Winter 2021 Autodesk 3D Printed Student Design Challenge. I am currently attending the College of San Mateo and was introduced to this contest by my professor.

This project has been something I have been interested in for a decent amount of time. We were recently getting rid of junk, and this particular section of a toddler gate caught my attention. I could immediately tell that it would be a great base or component for some project. This resulted in it getting rescued.

The purpose of this project was to find a creative use for the segment of the gate.

Materials used:

• 2x 1-by-3 in Wooden Boards, salvaged from a bed frame
• 1x Segment of Toddler Gate
• 12x #6-1 in Drywall Screws (Leftover from a roofing project)
• 4x #8-2 in Wood Screws (Leftover from a roofing project)
• 1.75 mm PLA filament

Tools & other supplies:

• Electric Drill and Impact Wrench
• Digital Caliper
• Drill Bits
• Hand Saw
• Pencil
• Ruler
• 3D Printer (Bed Size 300x300 mm)

Software used:

• Fusion 360
• Ultimaker Cura

The bars of the rack immediately reminded me of a Slatwall or a rail storage system. Slatwall is a modular display and storage, featuring a grooved wall from which hangers can quickly be removed. They are held up under their own weight by a lever. They are installed on a wall and serve to utilize space more efficiently by storing items vertically. The bars could function as the slats, simply lacking the back.

I then started to think of items that would store well vertically, and one of the first things that came to mind was a vertical planter. However, most vertical planters have the plants grow directly in them, and can be easily repositioned. 

I started to think of a combination of rail storage and vertical planter, with rail units that could be designed to hold plant pots. It would have the advantage of a Slackwall, which is fairly strong and robust, so should be capable of holding small pots while being watered, and repositionable to easily change the location of the pots if needed or even remove them.

The design of the hooks for a Slatwall or storage rail is quite complex and would be extremely difficult to make by hand. However, with 3D printing, making the shape becomes much easier and the challenge more so becomes the strength of the part. Luckily, since most of the external forces are in a certain plane, and is mounted to a set of bars offering much more space to design, 3D printing the brackets to hold the parts is a viable option.

Before I started drawing, I gathered the key materials (pots, wood boards, and the gate section), to see if it was even practical to create. My pots were mostly 3in, with a 5in pot (the big blue one). I wanted to see if it would be practical to try and hang any of those pots from the gate. At least for the small pots, it appears to be a pretty space-efficient solution. They can be hung fairly close to the gate, and don't weigh too much even when planted.

I focused on making it strong, so it could hold the weight of many pots that were being watered, but also considered what could make it look somewhat nice. I decided that an inverted T with the bottom boards mounted perpendicular to the height boards would be the strongest shape. 

Assembly:

1. The gate was used to measure the length of the board to cut, then marked with a pencil. Measure twice, cut once. The cut board was then used as a stencil to duplicate the other side.
2. The boards were then aligned with the posts of the gate, and pilot holes were shallowly drilled into the back of the board through the punches in the gate. The gate was then screwed to the board via the punch and pilot holes. This was repeated on the other side. 
3. The partial frame was propped upright and scraps from curing the first 2 boards were used to determine the length of the foot. The length and the location of the screws were marked on the board. It was then cut and pilot holes were drilled all of the way through. It was then duplicated.
4. The foot was then aligned with the partial frame, and the drill bit was used to mark the center of the holes. Deep pilot holes were drilled to prevent splitting. This was repeated on the other side. 
5. The foot was then screwed into the frame to complete it.

The original idea for the hook was similar to a Slatwall, where a hanger can be quickly moved to any height. However, this relies on the gap between the bars in the rack being relatively small, and the frame was not as much. The hook was redesigned to be more hanger-like and to support most of its weight by hanging from the top bar rather than resting on the lower one. 

Before 3D modeling, a sketch was created to solidify the exact shape and components of the design.

Parts produced by FDM 3D Printers (Fused material deposition, filament-based printers) are not known for their overall strength. Parts are printed in layers, which adhere to each other. They are not fused and tend to delaminate easily when forces are applied perpendicular to the layers. However, when forces are applied parallel to the layers, the part’s strength can be comparable to that of a solid part made from the same material.

Most if not all of the external forces to the part act along the same plane. In the 3d model, this is the x (forward/backward) and z (up/down) plane. The main load-bearing component was designed to be printed laying down.

The loop component was designed as a separate component in order to simplify the printing process. It is attached to the main component via 3 coarse screws.

The model was designed parametrically so I could accommodate and hang different pots. The key dimensions of the pots were a relevant diameter and the height from the base to that diameter. The holes and spacing for the screws were also parametrically defined in order to accommodate different screws if needed. 

The diameter and height of each of the pots were measured with a caliper, as shown above. The parameters of the model were changed so that they would fit the dimensions, and a mesh (STL) of each model was saved. The assembly holes were defined for #6-1in Drywall screws, the same used when assembling the frame.

Each mesh was sliced in Cura for 3D printing. The layer height was set at 0.3mm and infill at 20%. The files were then printed in PLA at 225 C. In my experience, these parameters have had the best balance of quality, material usage, and speed. Printing at 225 degrees for this particular filament will also create better layer adhesion and strength. No brim or supports were used in order to reduce the time needed for post-processing.

The hook was assembled by simply screwing the loop into the load-bearing component.

The pot is inserted into the hook and then hung onto the frame. The frame can then be positioned to get just the right amount of exposure to light needed for its plants.

I had a lot of fun building and designing this project, and overall am extremely satisfied with how it turned out. It looks very nice and functions just as well as intended. It is useful and will definitely continue to be in the future.

One thing that went very well was the construction of the frame. Planning out a design that sorted out almost everything but the dimensions made putting it together really smooth and without any hiccups.

One thing that could've gone better was designing the model for the hook. The parametric design turned out to be a challenge, and many relationships would break when the parameters were updated. I managed to get most of it working, but some features like fillets and chamfers do not update properly and need to be redefined. Aside from that, the hooks were modeled well, printed well, and were installed on the frame with no problem. Each also supported the weight of its pot without issue.

In the future, I will spend a lot more time designing a model to be properly parametric. What seemed like the simplest way, creating a set of baseline sketches, may not be the best. I will have to experiment with and test different strategies in order to find what works the best. 

I think this will be a great project for me to revisit sometime and see if I can make improvements and do it better. Because the materials available to me may be drastically different, I doubt the two will be at all comparable, but overall I'm sure it will be fun and worth my time.