Introduction: A Transportable Kendo Dummy

About: For work I am a scientific instrumentation consultant and my hobbies are woodworking, electronics, gardening, etc ... anything that serves as a creative outlet.

I have always wanted to build a kendo practice dummy for home use and kept some old bogu (kendo armour) just for that purpose. Back in March the pandemic shut down our regular indoor kendo practice and that prompted me to make it happen. Originally the dummy was suppose to be for use on my deck or lawn, but I decided to make it transportable so others could use it as well. Our club still meets, but it is in a school field where we can keep distance from each other. I wanted a dummy I could transport to that location and also move around the field as needed for the various members of our group to use it.

Step 1: Design Details

In order for the dummy to be transportable, it would have to fit the trunk of our car (mid sized sedan). No part could be longer than about 39 1/2” (100 cm) or taller than about 18” (46 cm). I decided to make the dummy in 3 parts that could be easily assembled or disassembled on site.

I also wanted to be able to adjust the height so it would not just be suitable for me (I am 6’ 1” or 185 cm), but also for those who are shorter than me. I came up with the design shown here, consisting of a base, center connecting column and top (that holds the armour). The column is fixed to the base and top with wooden pins. Everything was to be made from wood to keep it lightweight. Of course it also had to have wheels to be able to cart it around.

Step 2: Supplies Needed

The dummy was built from scrap pieces of lumber, etc that I had around the house. I suggest the following:

  • Some 2x4 or 2x6 pieces that can be ripped to size
  • Some ¾” (19mm) plywood for the column
  • Some 1x3 pieces that can be trimmed to size
  • A pair of wheels and a mounting bracket for them
  • 2 screw in hooks (or eyelets that can be cut/bent open)
  • Some ½” dowel (roughly 12.5mm) and a matching drill bit
  • Wood glue, screws, nails and some paste wax
  • Some stain or coating (optional), I used milk paint

For those not familiar with the dimensional lumber sizing in North America, a 2x4 is actually 1 ½” x 3 ½“ and a 1x3 is ¾” by 2 ½” (1" = 25.4mm). If you build this yourself, you can adjust the dimensions to whatever material you have that available and not worry about these specific dimensional lumber measurements. You could make some parts out of metal as well, but I wanted to keep it light so the parts would be easier to carry when needed.

The wheels were salvaged from an old kids’ bike training wheels and the metal mounting brackets were part of our old garage door opener. Lawnmower wheels or anything similar would work just fine as well.

Step 3: Construction Details

Since I was using left over lumber (mostly scraps and cut-offs), all wood components were cut to size to give clean mating surfaces. Assembly was done with glue and also screws when possible. A brad nailer was used to keep the parts in position for the column, since screws would not hold all that well in end grain of the plywood anyway. The base was built first, since I needed a reference point for the overall height and at the time I hadn't even decided how I was going to build the top section.

Step 4: Base Construction

As I said, I began construction with the base. The base upright and the “backbone” from the top (see drawing of top) had to be the exact same size as they would slide into the column, so they were cut out of the same piece. The top edges of the upright were slightly chamfered to make it easier to slide the column onto it. The parts were glued and screwed together with 2” (about 50mm) deck screws. The wheels were mounted with the bolts they came with and the wheel brackets screwed to the base frame with 1- ½” deck screws. A couple of square disks were cut from some maple scraps to make bushings so the wheels would not rub on the metal mounting brackets. Since I also planned to use this on my deck, I mounted two nylon glides on the front underside of the base, so it would not damage the vinyl deck covering. Those are entirely optional and definitely not needed if you are using this on a lawn or field.

Step 5: Center Column Construction

The column parts were glued together while using the base upright and the top “backbone” as a sizing guide to ensure a snug fit. Once a few brads were nailed in, those two pieces (upright and “backbone”) were removed and the glue was allowed to set. I was not worried the fit would be too tight. I intended to sand both the upright and backbone smooth until they fit perfectly inside the column and give them a liberal coat of paste wax as well. The holes for the dowel pins were drilled with the column sitting on the base and the top (once constructed) clamped at one of the heights I had planned. The dowel pins were made from maple and I checked that their diameter matched a drill bit I had available. They were also coated with paste wax to make them slide in a bit easier. Later I attached each dowel to the column with some string and screws, so if they did fall out during transport I would not lose them. The remaining height positions were then also drilled with the top (once constructed) in place as well and the height written on the side of the backbone part.

Step 6: Top Section Construction & Final Assembly

All parts for the top were glued and screwed together. The drawings for the top were made well after the unit was built, since I did not know the optimal way to attach the men (kendo mask/helmet). There may be a better way yet, but this is what I came up with. In the drawings the block that holds the back support at the correct distance is shown as one piece. However, as you can see from the photo, it was made from several pieces in an attempt to fine-tune the design. The notch was needed to keep the himo (strings) in place to ensure the men did not move around (see photo of back view). The men is not tied in the same way it would be if it were on a person's head. This was intentional, I wanted it to be easier/quicker to remove it if needed.

There is a small block of wood glued to the bottom of the back support that prevents the kendo do (chest armour) himo from sliding off the bottom (see photo). The himo wrap around the support snugly a few times and this secures the do very well.

The two round disks on top were meant to help position the men by mimicking the shape of a head. However, as can been seen from the photo showing the back, the rear disk does not make contact. It could have been made larger or perhaps wasn’t as necessary as I originally thought.

Finally, the entire project was given two coats of blue milk paint as a bit of a protective coating and then I coated everything with paste wax as well to help keep the moisture out. It rains quite a bit here during the winter and the dummy will be outside on the deck under a rain cover during that time.

Step 7: End Result

The dummy works quite well. It has been in use for about 3 months and transported to and from our outdoor practice location several times already. It fits well within the trunk of the car and, once assembled, it can be easily wheeled around by grasping the back-support piece and pulling it along. It is stable and has only been knocked over once when someone actually ran into it. Striking it has never knocked it over, nor has performing tsuki (stab to the throat guard).

I have plans to build movable (and removable for transport) arms that will have kote (gauntlets)on them and hold a shinai (bamboo sword). I have some ideas on how to do this, but not yet implemented them yet.

Make it Move Contest 2020

Participated in the
Make it Move Contest 2020