How to Build an Even Better Wing Chun Spring-Arm Trainer
A few months ago I came across this great article on how to build a Wing Chun Spring-Arm Training Device. Having finally gotten around to starting one, I began shopping around for the parts. During my search I was inspired to make a couple of enhancements that you might consider if you are looking to build one of your own. (DO check out the original article. Big Thanks to John Cook for writing the article. I never would have thought about building one of these without it!)
The major changes to the design are that the arm is not a piece of plastic stock but instead a Bat which gives it a shape more like an arm (without increasing the cost) and the arm position is ADJUSTABLE. By the way, this thing only cost me about $50 to build!
I am not endorsing that you copy either my design or the original design to the letter. I suggest you read both 'How-to's" and take what you like from both. That said, here is an overview of how I built mine.*
Parts I used:
(1) 1/2" Washer
(1) 3/8" lock washer
(1) 1/2" lock washer
(3) 1" wood screws
(1) 1/2-20 x 2 1/2" Bolt (fine thread)
(1) 3/8-24 x 3 1/2" Bolt (fine thread)
(1) 3/4" x 11 3/4" x 34" Pine Board
(3) 3/4" x 11 3/4" x 2 1/2" Oak boards
(1) 3/4" x 26 1/4" x 2 1/2" Oak board
a couple dozen brad nails (probably optional)
Wood stain (optional)
Temporary Threadlock (optional)
I used the plastic Bat from Cold Steel as listed above but solid plastic stock would have worked too. The cost was about the same to mail-order plastic stock or to get the bat from Amazon, so I opted for benefit of the funky contours.
-Cut the bat off to a length of 18 3/4". The length could vary but that is what I settled on for mine. Make sure you measure from the handle end if you use a bat. You can only cut this too short once (because then you are hosed).
-Cut off the head of the 3/8-24 x 3 1/2" bolt (I used a Dremel) and rough up the left over shaft (but not the threads).
-Clean up the trimmed end of the bat with some sandpaper and/or a utility knife.
-Drill a 3" plus deep x 3/8" wide hole in the cut off end of the bat. (Careful not to drill your hand, dummy.)
-Mix up your JB Weld and then spread it on the shaft of the bolt keeping it off the threads. (Other epoxies may work just as well but this is what I had laying around.)
-Glue the cut bolt into the hole in the bat so that only 7/8" of threads stick out. Clean off any excess adhesive. Let this dry overnight.
You can build the platform any number of ways but make sure you leave in a provision to access the adjustment nut on the back of the ball-joint. I just slapped one together with scraps of lumber I already had. Also, the mount could possibly be screwed directly to a wall or beam if you like, but adjustments might be hindered as you need access to the back bolt to fully adjust the ball-joint. The front of this one is a pine laminate board and the slats on the back are oak for extra strength. They were glued, clamped, and then tacked together with an compressor driven brad-nailer. After that all dried for a day, I stained the front and sides for the sake of aesthetics.
Mounting the Mount
I mounted the ball-joint to the end of my platform with the double slats. Your methodology may vary if you build a different platform.
-Drill a pilot hole for a paddle bit.
-On the backside of the platform, drill a hole as wide as the 1/2" washer and just deep enough to recess the 1/2" washer, 1/2" lock washer, and head of the 1/2" bolt so they didn't stick of the back. (A 1 3/8" paddle bit was the ticket for mine. Your mileage may vary. I could have skipped this step but I would need a slightly longer bolt and the head would have stuck out the back.)
-Drill a 1/2" hole in the center of the recess for the big bolt to go through.
-Attach the ball-joint, including the black plastic base, to the platform with the 1/2" washer, 1/2" lock washer, and 1/2" bolt. Tighten with a wrench and make sure it is straight on the front side. Do not over tighten.
-Screw the three wood screws into the holes in the plastic base to prevent unwanted rotation.
-Screw the spring and then the arm onto the ball-joint using the 3/8" lock washer. Also, I used Temporary Threadlock to reduce unwanted unscrewing.
Attached your favorite wall bag or makiwara to the front. The one pictured was purchased here from Everything Wing Chun. They have many great options to fulfill your personal tastes.
Hanging the Whole Shabang
There are so many factors that can go into how to hang your new monstrosity that I will not give any specific advice. Make sure it is REALLY secure and will not fall off your wall or post or whatever you mount it to. Methods will vary greatly according to what you are mounting to. Be safe.
Enjoy your new training toy!
*This whole project requires some handy-man skills to complete safely. Do not attempt to recreate the above crafts adventure if you are unfamiliar with the safe operation of any of the tools pictured or described. BUILD AT YOUR OWN RISK!
Sifu Nick Edmonds
Red Light Wing Chun Phoenix, Arizona