Making a quadripod bamboo speaker for smartphone. With simple tools
This acoustic bamboo speaker is quite quick to build. As for all our bamboo crafts, you can make it entirely with manual tools. It does not contain nails nor glue to join parts but only bamboo dowels.
Compared to the bamboo trivet and the underwear dryer, however, you need to use one more technique: carving. It is indeed necessary to create larger openings than what we can do with a driller, like the one we need to insert the smartphone into the amplifier.
If you haven’t tried using carving tools so far, don’t be shy! For this object you will only need to make one opening. It is a good opportunity to learn.
- Level: fairly easy (although carving may require a little bit of trial)
- Building time: a few hours
- Size: 24 cm long (about 9.5 in)
This post is part of my bamboo craft project. If you are looking for something a little bit easier to make, check out our bamboo trivet or our underwear dryer. For something more complex, check out the tutorial for the large bamboo shelf.
Table of content
Material and tools needed
You need a bamboo pole of about 20-30 cm long (8-12 in) and 5-8 cm in diameter (2-3 in). If you don’t have access to such a pole, no worries, you may have to adapt the size, and you will just obtain a different speaker! However, the length, the diameter, and the thickness of your bamboo pole will definitely affect the sound performances.
For our version of 24 cm long (9.5 in), 5.5 cm in diameter (2 in), and 0.5 cm thick (0.2 in), the sound is indeed amplified but with a tendency to enhance more medium to high pitches. A larger diameter may likely be more efficient at enhancing low pitches. If I try some experiments to find optimal dimensions, I will definitely share them here in the future!
You can use a fresh or dry bamboo pole. It can be easier to work with fresh bamboo, as it is tender and more flexible, but there is a risk that some cracks appear when it dries later. On the contrary, dry bamboo can be tougher and more brittle, so some craftsmen will soak the dry bamboo in water for a day before working on it.
For this tutorial, I used a bamboo pole freshly cut. Everything was fine for a year, but after we moved to a slightly drier microclimate, some cracks appeared, as you can see in the picture.
- matchet or knife
- tape measure
- cutter and/or sandpaper
- chisel (wood carving tool with a straight cutting edge)
- gouge (chisel with a curved cutting edge)
- manual or electrical driller
- wood support to immobilize your bamboo when working on it
- safety gloves
Wear gloves for safety!
It is always a good idea to wear gloves if you are a beginner, at least one glove for the more vulnerable hand that is holding the bamboo when you use a tool.
Saw a cylinder of bamboo
First, you need to saw a cylinder of 20-30 cm long (8-12 in) or your custom length. Depending on the style you are looking for, you can choose to cut at the location of the nodes, as I did, or to cut between two nodes to obtain a node-free cylinder. Some people also make bamboo speakers with slant cuts. I don’t know how this parameter affects the sound performances of the speaker.
Carve a slot in the cylinder
To carve the slot, you need to report the width and thickness of your smarphone on the center of your bamboo cylinder. Don’t forget to account for the cover of your smartphone if you have one! In my case, the slot is 1.3 × 8.3 cm (0.5 × 3.3 in).
You can start to carve the slot on the two short edges , using the gouge. The curved cutting edge of the gouge will help to carve a rounded rectangle. You could also use the chisel with the straight cutting edge to make a rectangular opening if you prefer.
Then, you can open the hole by cutting the longer edges of the opening, using the chisel with the straight cutting edge. As you already cut the fibers on the two short edges of the rectangle, the bamboo piece is bound to detach easily.
Finally, you can sand the edges of the hole using the chisels, a small knife, and/or sandpaper.
Drill 4 holes for the pods
To drill the holes for the pods, you can use a manual or electrical driller. Here I used an electric driller with a drill bit of 6 mm in diameter (0.25 in). This large diameter gives strength and stability to the speaker, and wide pods are a bit easier to make than thinner ones.
First, you can identify the opposite side of the slot. Then you can mark the location of the pods with a pencil. I located the pods at a distance to the edges of 1/4 of the total length of the cylinder, that is, longitudinally, each pod is located at 6 cm from the edge (2.4 in) and 12 cm from the other pod (4.8 in). And, transversally, I separated the pods by 1/4 of the circumference of the cylinder, that is, about 4 cm (2.4 in). You can, of course, use your custom measurements for a different style.
In order to obtain a horizontal and stable speaker, it is easier to drill the holes of the pods perpendicularly to the surface of the bamboo cylinder. This will help you to make the four pods identical, as a 90° angle is usually easier to make and replicate visually.
Note that you also have the possibility of drilling 4 additional holes to insert two horizontal supports inside your bamboo amplifier. They can help maintain your smartphone in a stable position.
They can also be necessary if your bamboo pole is quite wide as you probably don’t want your smartphone to be half-hidden inside the speaker.
Sand the cylinder
This step is optional and depends on the bamboo pole you have access to and the style you want to accomplish.
If the skin of your bamboo pole is clean and not damaged, you may want to skip this step and keep its sheen. If it is a bit damaged, not clean, or if it developed some patterns during the drying process — as it did in my case — you may want to sand it for a more even finish.
To sand the skin of your bamboo pole, you can use sandpaper. It is also possible to start by scrapping the skin with a cutter or a knife before using sandpaper. The cutter allows us to remove a thicker layer of skin than sandpaper, with a less demanding effort. Just watch your fingers!
Make the pods
Creating the pods is similar to creating dowels.
You can make the pods from a few bamboo slats. If you don’t have slats, you can split them from a bamboo cylinder that you would have sawed. In my case, the slats were 8.5 cm long (3.3 in).
However, my resulting pods have different length, ranging from about 7.5 to 8.5 cm (3 to 3.3 in). This was to correct the lack of stability of the speaker, due to an uneven shape of my bamboo cylinder and imprecisions in the drilling process. You can prepare 8.5 cm pods (3.3 in) and adjust them later to make sure your speaker is horizontal and stable.
To make pods, use your matchet or knife to split the slats into sticks the diameter of the holes you drilled, that is, 6 mm in my case (0.25 in).
As you can see, the section of the pods is round on the top to fit the holes and square on the bottom.
Join and adjust the pods
Insert the 4 pods in the holes you drilled. You can do it manually or using the flat side of your matchet as a hammer.
If you decided to add two inner dowels crossing your speaker to support the smartphone, you can insert them in the holes you prepared for them.
Likely, your bamboo speaker will not be stable at once. In this case, you can adjust the size of the pods, either by directly cutting a small chunk using shears or adjusting only a little bit with sandpaper. You can also use shears and sandpaper to cut and smoothen the surplus of the horizontal support dowels.
And that’s it, your smartphone amplifier is ready to use!
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