Around the beginning of 2012, I spent some time online trying to locate a freely available design for a martial arts board holder. At the time there was nothing available. So after taking some inspiration from a few commercially available compact designs (see: http://www.google.com/search?tbm=isch&q=board+holder+martial+arts) I came up with my own.
In this HowTo, I will show you how to make a collapsible martial arts board holder entirely out of broken Martial Arts boards. It can be easily attached to a heavy punching bag, held by a partner or supported against/hung on a wall.
From this pile of broken boards and equipment, we have everything we need to build it (plus a staple gun, which I forgot to put in the picture).
This HowTo details my Mark 6 version. I have used my Mark 4 version for nearly a year in my own classes with much success and durability. My Mark 5 and Mark 6 designs are an attempt to further simplify and refine the design (not to mention detail the process for this posting).
This build will take 2-4 hours start to finish (likely faster for someone who is a better carpenter than I) and about $10-20 in supplies. With a tiny bit of planning, these steps could be done in an assembly line fashion. Maybe at the yearly club BBQ a few members can work together to make a bunch of board holders for all the students who want one!?!
For this build, I will assume Martial Arts boards that are 290mm x 290mm x 19mm (11 1/2″ x 11 1/2″ x 3/4″). There is a bit of variability in each batch of boards, but we will address that issue as we go.
For reference, I recently found another HowTo detailing the build process of a non-collapsible board holder that has some very nice design ideas: http://www.karate.gregoryzone.org/?p=219 . It is worthwhile to have a look at this design to compare and contrast.
Board breaking/power breaking is not for beginners! The design presented below is intended for in-class use under the guidance of a professional instructor. The design and build instructions provided below are for informational purposes only. I assume no responsibility or liability for any injuries you may receive using a board holder based on the design detailed below.
Power Saw (preferably a Table Saw and a Drop Saw), Power Drill, Hammer, Tape Measure, Safety Glasses, Ear Plugs, Red Pen, Blue Pen, Black Pen, Drill Bits (sizes based on Screws/Eyelets), Philips Screw Head (matching Screws), Staple Gun (not pictured), Vice Grip (optional), Sand Paper/Sanding Block (optional).
Supplies (per board holder):
Non-toxic PVA/Elmers Wood Glue (100ml, 4oz), Non-Slip Fabric (two 290mm x 50mm, 11 1/2″ x 1 1/2″), Bungee Cord (two 1000mm, 40″), Philips Countersunk Screws (Sizes), Eyelets (four large enough for the Bungee Cord to pass through), Bungee Cord Hooks (optional)
General Tips & Tricks:
Pilot Holes: Since we are working with thin pieces of soft wood, pilot holes are essential to help ensure that the boards do not split when the screw is drilled in. In order to drill a proper pilot hole, you need to select a drill bit that is just a bit smaller than the center stalk of the screw (not including the threads). If you drill the hole too big, the screw’s threads won’t bite into the wood. If you drill a hole too small then you will not get the advantage of the pilot hole. Saying that, having a pilot hole that is too small is better than too big.
Another aspect of pilot holes to consider is that there is no need to drill deeper than the screw will go. In fact, I tend to drill a little short of the full depth to guarantee some full bite at the tip of the screw. As you can see in the image above, I placed the Drill Bit into the Drill such that I cannot over-drill the pilot hole’s depth for the Eyelet.
Lastly, be sure to sand/remove any fragments from the bottom of the pilot holes before gluing and screwing as an errant chunk of wood can keep you from getting a good flat gluing surface.
Countersunk Screws: I greatly prefer to use countersunk screws for safety and ascetic reasons; plus you can sand after screwing the pieces together. If you are using countersunk screws, make sure you consider the extra length this will add when selecting your screws.
Sanding: It is far easier to sand each piece individually before using it on the board holder, but some sanding will likely be required after assembly as well. Make life easier and sand as you go! Just remember to wipe surfaces clean of dust before gluing.
Gluing: I cannot stress enough how important it is to glue every piece. The Wood Glue will greatly extend the lifespan of your board holder. Once the glue has fully dried the screws are almost no longer required; it is that strong! If you forget, it is worth the time and effort to unscrew, glue and re-screw (which even I had to do on a few occasions while building my 5th and 6th board holders for this HowTo).
Always use enough glue to fully fill the gap between the pieces, but not so much as to make a big mess. You should always get a bit of wood glue that leaks out when you put the pieces together. Wipe off the excess with your fingertip, and use it to in-fill any previous gaps or edges. But note that Wood Glue is a pain to sand once it’s fully dry, so don’t just wipe it over every surface with the expectation that you can sand it off later.
1) Find two suitable boards to use for the Vertical Supports
Matching the two sides of a board from a pile of halves can be a challenge, but they are in there. Be sure to clean any board fragments from within the break to ensure that the two pieces can be cleanly and snugly glued back together. Also ensure that these boards are the same size as they will work as a pair to support the boards in the Board Breaker.
NOTE: You can use two unbroken boards if you wish for the Vertical Supports (but that is far less cool).
2) Start stripping!
With your table saw, start cutting the remaining broken boards into approximately 2.5cm (1 inch) strips, cutting with the grain. You will need at least 17 of these Board Strips for each holder (plus one for the ruler). I suggest making at least 25 Board Strips, just so you have plenty of spares just in case.
NOTE: It is worthwhile to save the offcuts of the broken boards as I make these into picture frames for belt certificates (this will be detailed in a future HowTo).
3) Make the Ruler
While this step isn’t absolutely necessary, it is a good idea to make up a Ruler so that you can quickly mark up the Board Strips. This Ruler will also be referred to in later steps.
Grab the ugliest of your cut Board Strips (or an offcut) and make the following markings:
- 2.5cm (1 inch) face: With a red pen mark a line on each end of the Board Strip 30mm (1 3/16″) in with a center cross. Mark one line in the center of the board (145mm or 5 3/4″) with a center cross.
- 19mm (3/4″) face: With a blue pen make a line at each end of the Board Strip 50mm (2″) in with a center cross. Mark one line in the center of the board (145mm or 5 3/4″) with a center cross.
- 19mm (3/4″) face: With a black pen make a line at each end of the Board Strip 13mm (1/2″) in with a center cross. Mark one line in the center of the board (145mm or 5 3/4″) with a center cross.
NOTE: These measurements are primarily to ensure that screws are run down the centerline of perpendicular Board Strips that will be attached in later steps. If you are off by a few mm (1/16″)s then it won’t matter too much. The crosses denote the location of the pilot holes to drill.
4) Prep the Back Board ends (Ruler’s red markings)
Grab the Ruler and two Board Strips, marking a 25mm (1″) face on each one with the red markings. Ensure these boards are the same length as they will form the ends of the Back Board.
Once your holes are marked, grab a drill bit smaller than the diameter of your screws and drill pilot holes at each dot.
5) Prep the Vertical Support Strips (Ruler’s blue markings)
Grab the Ruler and six Board Strips, marking on a 19mm (3/4″) face on each one with the blue markings. As you can see in the picture above, my Board Strips vary in length by more than a few mm (1/16″), line up one end with the end of the Ruler (the right side in the photo above) marking the dots from that point. On the uneven ends, mark the 19mm x 25mm (3/4″ x 1″) tops with a “T” to indicate these are the tops (which we will cut off in a later step).
Once your holes are marked, grab a drill bit smaller than the diameter of your screws and drill pilot holes at each dot.
6) Prep the Back Board sides (Ruler’s black markings)
Grab the Ruler and four Board Strips, marking a 25mm (1″) face on two of them with the black markings. Ensure these boards are the same length as they will form the sides of the Back Board.
Once your holes are marked on two of the four Board Strips, flip over the marked Board Strips and put a reasonable amount of Wood Glue onto the back. Attach the marked Board Strips to the unmarked Board Strips, ensuring that their edged meet up.
(Optional) attach vice grip to one end of the glued Board Strips prior to drilling to help ensure alignment. Alternately you can let the Wood Glue cure for a few minutes, allowing it to become tacky enough to hold the pieces together.
Grab a drill bit smaller than the diameter of your screws and drill pilot holes at each dot through the two boards. Once the pilot holes are drilled, put a screw in each end of the glued Board Strips to ensure a tight glue joint.
7) Grab your Vertical Supports and start gluing
NOTE: You can skip this step if you are using unbroken boards for your Vertical Supports.
Put a good amount of wood glue down one side of the break on each board, enough to ooze out a bit but not make a mess. Go ahead and do both boards as this will give the glue a few minutes to setup a bit to assist in the next step.
8) Attach the Vertical Support Strips
NOTE: You must ensure that the screws you use for this step do not poke through the Vertical Support! Any screw heads that poke through the other side will damage boards and limbs during breaks.
Double check that you have the glued Vertical Support Board with the proper face up, ensuring that any angles in the breakpoint down and into the Vertical Support Strips you are about to attach. See image above; the glued break runs from top left to bottom right within the red circle. And always run the Vertical Support Strips across the grain of the Vertical Support, else it can crack much more easily.
Put a reasonable amount of Wood Glue onto the back and attach the first Vertical Support Strip at the far left edge of the Vertical Support you prepared in step 7. After ensuring the bottom of the Vertical Support Strip lines up with the bottom of the Vertical Support, screw in the two screws that are on one side of the break in the Vertical Support. When attaching the third screw, be sure to force the Vertical Support together to ensure a tight fit.
Put a reasonable amount of Wood Glue onto the back and attach the second Vertical Support Strip. Use a Board Strip as a spacer at the far right edge of the Vertical Support, such that the second Vertical Support Strip is 19mm (3/4″) off the far right of the Vertical Support (we do this so that the two finished Vertical Supports can be stacked back-to-back). As before, after ensuring the bottom of the Vertical Support Strip lines up with the bottom of the Vertical Support, screw in the two screws that are on one side of the break in the Vertical Support. When attaching the third screw, be sure to force the Vertical Support together to ensure a tight fit.
Put a reasonable amount of Wood Glue onto the back and attach the third Vertical Support Strip. Use five Board Strips on the left side and six Board Strips on the right side to position the third Vertical Support Strip slightly off center (we do this so that the two finished Vertical Supports can be stacked back-to-back, see image below). The twelve Board Strips should fit pretty snugly. After ensuring the bottom of the Vertical Support Strip lines up with the bottom of the Vertical Support, screw in the three screws.
Remove the spacer Board Strips, clean up any excess Wood Glue with your fingertip (working the excess into any gaps) and set the finished Vertical Support to the side.
Repeat this procedure for the second Vertical Support.
9) Cut Vertical Support Strips along top
NOTE: The table saw in the picture is missing its blade guard in order to show the angle of the blade only. This is a very dangerous configuration. Do not use a table saw without a blade guard installed! Also note that the tops of the Vertical Support Strips can be knocked off by the blade during the cut, so be very careful with this step! Before committing to the cut, ensure that the top screw will not come into contact with the blade!
As the Vertical Support Strips are located on the outside of the Board Holder, there is an outside chance that a strike could hit these supports. As a safety measure, these supports are cut at a 45 degree angle to limit damage should a strike come into contact with them. The trick with this step is to ensure that the Vertical Supports end up the same height. My table saw doesn’t make a full cut, so I have to do a secondary cut to level off the top of the Vertical Support.
Now the Vertical Supports are complete. As you can see above, we offset the Vertical Support Strips to allow for back-to-back stacking on the finished Back Board (which we will get to in the next step).
NOTE: Be sure to cut off the tops marked with a “T” in step 5 as the other end should be in line with the bottom of the Vertical Supports.
10) Assemble the Back Board
NOTE: Be sure to read through this step once or twice before proceeding as it is somewhat complicated.
Take the Board Strips you prepared in steps 4 and 6. Remove the screws from the glued side Board Strips (Black).
Position an end Board Strip (Red) at the 38mm x 25mm (1 1/2″ x 1″) end of one of the Black Strips and drill a pilot hole into the Black Strip through the hole in the Red Strip. Put a reasonable amount of Wood Glue onto the 38mm x 25mm (1 1/2″ x 1″) Black Strip end and screw the Red Strip onto the Black Strip. Repeat this procedure for each of the remaining three corners. (Optional) Using the vice grip to hold the glued end together can be helpful.
NOTE: It is critical that the faces of the boards line up at the corners to ensure square corners as well as a flat back surface of the board holder/Back Board for power breaks (as this area will be held against a solid wall and should sit flat against it).
Once you have the outer Back Board frame glued and screwed together (forming a rectangle), we need to cut the three internal supports from Board Strips. You want to ensure that these three Board Strips fit very snugly into the inside of the frame, so cut one at a time a little long and slowly cut each it back with the drop saw until you can just barely shove the board into position. This snug fit helps to ensure a solid Back Board.
Once you have each Board Strip cut to size, remove it, put a reasonable amount of Wood Glue onto the faces that come into contact with the Back Board and put it back into positon. Drill out the pilot holes through the Red and Black Board holes and screw together. Note that the Board Strip in the middle is positioned with the 19mm (3/4″) side up, while the two outer Board Strips are positioned with the 25mm (1″) side up. In order to make it easier to have a flat front and back face on the Back Board, the two outer internal supports are positioned in the center vertically.
11) Attach Vertical Support Footings to the Back Board
NOTE: As with the internal supports from step 10, it is important that these Vertical Support Footings are very snug. This snug fit helps to ensure a solid Vertical Support and is the most critical part of the build.
Cut one Vertical Support Footing at a time a little long and slowly cut each back with the drop saw until you can just barely shove the board into position.
Once you have each Board Strip cut to size, remove it and mark one hole on each end on a 19mm (3/4″) face approximately 30mm (1 3/16″) from each end on the centerline.
Drill out the pilot holes and screw in the screws so that they stick out slightly from the bottom. Position the Vertical Support Footing back in the Vertical Support, then place the Vertical Support on top of the Back Board above the Red Board ends such that the sides of the Vertical Support line up with the sides of the Back Board, and the Vertical Support Footings line up with the ends of the Back Board.
Use the Hammer to tap the heads of the screws, marking the position of the screws into the Back Board. Drill the pilot holes into the Back Board then put a reasonable amount of Wood Glue onto the bottom of the Vertical Support Footing. Screw in the Vertical Support Footing.
Repeat this procedure for each of the four Vertical Support Footings.
12) Attach Internal Vertical Support Footings to the Back Board
NOTE: As with the internal supports from step 10, it is important that these Internal Vertical Support Footings are very snug. This snug fit helps to ensure a solid Vertical Support and is the most critical part of the build.
Cut four approximately 38mm (1 1/2″) Board Strips for use as the Internal Vertical Support Footings. Mark a pilot hole in the center of a 25mm (1″) face of each Internal Vertical Support Footings, drilling each pilot hole and putting a reasonable amount of Wood Glue onto the bottom of each of the Internal Vertical Support Footings.
Using a spare Board Strip, position it in the place of the Vertical Support. Wedge this Board Strip into place with the Internal Vertical Support Footing, screwing each one into place.
NOTE: There is no need to drill a pilot hole into the Back Board under the Internal Vertical Support Footings as the screw will be in the gap between the sides of the Back Board.
13) Attach Eyelets and Bungee Cords to the Back Board
Mark pilot holes under each of the Internal Vertical Support Footings, ensuring to miss the screws holding the Internal Vertical Support Footings. Drill out the pilot holes and install the Eyelets into the Back Board.
Get an approximately 850mm (33 1/2″) length of Bungee Cord, threading each end through an Eyelet on each side of a Vertical Support.
To attach the Bungee Cord, you can simply tie a knot in the end (as pictured above) or use some Bungee Cord Hooks like those pictured below.
Using hooks like this will allow you to also use the eyelets to attach the board holder to a heavy punching bag, tree, post or otherwise (as Ryan Gregory did with his holder, see: http://www.karate.gregoryzone.org/?p=219 ).
14) Attach Non-Slip Fabric to Vertical Supports
Using a Staple Gun, attach a double thickness of Non-Slip Fabric to the top face of the Vertical Supports. The Non-Slip Fabric, along with the Bungee Cords keeps the boards in place.
One of the newest features/improvements with the Mark 6 is the attachment of the Bungee Cords to the Back Board rather than the Vertical Supports. Im still getting used to wrapping the cords around the Vertical Supports when in storage, but I think the parallel approach below works the best:
Also note that when collapsed, the board holder is only slightly taller than my four UMAB re-breakable boards. Not a bad footprint at all!
Q: “Yea, that looks cool and everything, but how well does it actually preform?”
A: Let’s go to the YouTube…
So… while I wouldn’t recommend The Broken Board Holder as a “power frame”, it still performs extremely well under some rather large power breaks. Plus due to the fact that it’s collapsible, if things go wildly wrong it should be more forgiving to limbs than a rigid holder would be. Notice how the holder is strong enough to allow for the breaking of the 4x UMAB boards in the video above, yet the Vertical Supports break away when they are pushed from the inside.
Best of luck, and happy building!