Intro: Japanese Bamboo Stilts
I made these for my kids, then aged six and eight, but they are strong enough to hold a 206 pound, six-foot adult (with some creaking). There is nothing critical about any of the measurements--feel free to adjust to your preferences. But I will give the measurements of the items I used. I am not Japanese, by the way. I learned how to make these from a youtube video of a Japanese man making them, but I modified the design not to use any screws.
- Two bamboo poles, approximately six feet long, approximately 1.3" wide (1.4" near bottom, 1.2" near top); best if without splits
- Four pieces of wood, 10" x 1.5" x 3/4"; I used some unidentified softwood
- Jute twine
- Optional: wood glue (I use Titebond II)
- Optional: duct tape (I will discuss alternatives at a later step)
- Saw that can cut bamboo (e.g., a fine-tooth hacksaw)
- Optional: woodworking clamps
Notes on bamboo:
Here in central Texas bamboo just grows like a weed. I acquired a bunch of nice poles ("culms" is the technical name) from an ad in the free section of Craigslist, and then they sat and dried in my garage for about a year while I was figuring out what to do with them. You can make the stilts out of green bamboo, too, I think, but the optional Step 6 probably will need some replacement, since I expect glue won't stick to green bamboo no matter how much you scrape. If you live in an area where there is lots of bamboo, you might advertise on Craigslist (or your local equivalent) that you want some. You can also order poles online.
Bamboo is an excellent building material, but it presents two challenges, the first minor and the second major.
First, few glues will stick to the outside of bamboo as it stands, since it is covered with a wax that prevents sticking. If you want to glue anything (exception: duct tape--it just sticks) to bamboo, you need to scrape the surface to get past the wax.
Second, bamboo is liable to split. This means that you should not use nails or screws in bamboo. I cringe when I see an otherwise nice bamboo fence made with wood screws. You want to tie bamboo, not nail or screw it.
Step 1: Cutting the Poles
I found that 68" long poles worked just fine for a six-year-old, an eight-year-old and me, a six-foot-tall man. You'll find your bamboo is wider at one end. That'll be the bottom end. I cut each pole so that it would have a septum 9.5" from the bottom--the septa are the joints between bamboo segments. You want to get these distances pretty close to each other on the two poles. The septum will help keep the footrests from sliding down. If you want the footrests higher, cut further from the septa.
I had to clamp the poles down to cut them comfortably, and unfortunately did have some splitting. I think a finer-toothed saw would have helped.
Step 2: Tying on Footrests
The footrests for each pole were made from two pieces of 1.5" x 3/4" wood that I had in my scrap pile, and I cut them to 10". A little longer would be better for bigger feet (like mine), but was fine for the kids.
The first thing to do is to lay the pole on the ground, and sandwich it tightly between the two footrest boards, as in the first photo. Place the footrest boards so that they extend about 1.5" below the septa, and then go up from there. Then tie the sandwich together very tightly with a very generous amount of twine, with the center of the twine about 2.5" from the bottom end of the footrest boards.
Tie off the twine.
The photo on this page and the photos on the next are from a re-enactment after the stilts were assembled. Since I am submitting this to the sustainability contest, I didn't want to waste any bamboo, wood or string for making photos afterwards, so the pieces aren't quite the right length. I also notice that the septum is in the wrong place, too--sorry.
Step 3: Angling the Footrest Boards
After tying off the twine (I don't in the photos, so as not to waste any), grab the two footrest boards and twist their long ends away from the bamboo by about 70 degrees. (If you go for a full 90 degrees, the weight of the person will probably push them too far down.) The twine should resist you. If you can moderately easily push the footrest boards to 90 degrees, it's because you didn't use enough twine or didn't tighten the twine in the previous step. You want the footrests not to go below horizontal after all. So if it's not tight enough, start over with the twine, or just add more.
Step 4: Tying the Footrest Boards Together
Once you have the two footrest boards at about 70 degrees, squeeze their ends together to make a V-shape and tie them together. This works better if the boards are fairly rough so the twine doesn't slip off them. Jute twine has a lot of friction, so it should keep in place. Tie off the twine.
My original instructions included this: "Soak the twine at the joints in wood glue, or (assuming this is PVA glue) wood glue diluted 1:1 with water for better penetration. Allow 12-24 hours to set. Don't worry, the glue will not stick to the bamboo." I don't recommend this any more as the wood glue encased twine becomes brittle over time, especially when stored outdoors. When I rebuild the project, I plan to try using Shoe Goo and maybe paracord.
Step 5: Optional: Duct Tape to Protect Ends and Prevent Splitting
To protect the ends from splitting, I put duct tape around them. On the bottom side, I put a lot of duct tape to make booties.
Another method to help prevent splitting would be to tie gluey twine (see the next step) around the top and bottom segments, which are in the greatest danger of splitting. And then maybe wrap some thick scrap cloth around the bottom to make booties to protect the bottom of the bamboo.
Step 6: Optional: Add a Ring to Keep Footrests From Slipping
The initial design used the septa to prevent the footrest from slipping too far down. That didn't work quite so well for us, though it may work better for you (it no doubt depends on how much the septa stick out). I think the weight of the person exerted enough friction that most of the time the footrests stayed put while walking, but eventually they would slide down.
The method I ended up using for this was to make gluey twine rings to hold the footrests up: I scraped off a 1/2" wide ring just above the septum so that glue would have something to grab, without the wax covering the bamboo pole getting in the way.
I took a bunch of twine and soaked it in a mixture of water and wood glue. I then tied that a number of times around the scraped area, making a ring (I think I ended up making a thicker ring than in the first photo). I tied that off, and to glue it tighly, I used clamps (with plastic jaws that wouldn't stick) to hold the ring tight to the bamboo, especially the loose ends of the twine past the knot. Once the glue set, the rings were well attached. The footrests then go above the rings.
Update: The brittleness of twine + wood glue may be less critical here, but I still think something like Shoe Goo might be a better bet.
Step 7: Finished!
I strongly recommend wearing a helmet (e.g., a bicycle one) while on the stilts and starting off on grass for safety, especially for children. Some excellent additional safety advice for stilts is here (I have no connection with that company).
There are many youtube videos of people walking on Japanese stilts. I like this one.
Walking on stilts is surprisingly challenging. Try and try again!