How To Make a Free-Standing Reflex Punching Bag Using The Kewlus Spring

cobra bag, diy, reflex bag -

How To Make a Free-Standing Reflex Punching Bag Using The Kewlus Spring


Making your own free-standing reflex punching bag (or cobra bag) is easier than you think. It will also save you hundreds of dollars if you're thinking about getting one.

The best part about the DIY version is that it is easy to put up and put away, unlike the commercial versions which all come with a massive stand that you have to fill with water. Water-filled stands can be a hazard  in your home as they are difficult to move and if they split you'll have water all over your carpet.

With the Kewlus Spring you can make a fast reflex/cobra bag that rivals any that are on the market. Just check out this video to see it in action:

Items You Will Need:

  • Kewlus Spring (KS9) (US $29) - I designed and produced this spring specifically for the purpose, taking out all the guesswork.
  • Base pipe (mast) - galvanised 3/4 inch pipe roughly half your height in length. The outer diameter of the pipe is 1.05 inches or 26.7mm and fits perfectly into the Kewlus Spring.
  • Galvanised flange to fit the mast pipe, a set of nuts and bolts to fit the flange and an MDF board for your base - roughly 2ft x 2ft. See video for preview. Alternatively you can simply use a concrete garden umbrella stand.
  • Roll of cheap duct tape.
  • PVC pipe - same outer diameter as the 3/4 inch galvanised pipe (1.05 inches or 26.7mm). Roughly two foot long.
  • Two pool noodles.

4-Step Instructions:

  1. Measure off and cut 20 inches of 3/4 inch PVC pipe that will form the arm of your punching bag. Cut a section of pool noodle to use as your punching bar base. I recommend about a foot. Slot it onto your PVC pipe until it goes all the way to the end. Take another section of pool noodle (roughly 18 inches) and split it lengthwise so you'll have two halves. Wrap these around the base section. Take a longer split section and wrap that around the base of the top ball. Finish by taping the whole shape from top to bottom until fully covered. It's best to explained in this video: This is your punching bag or speed ball.
  2. Setup up your base by bolting the flange to the centre of your MDF board. If using an umbrella base, remove the plastic insert from the top of the base pipe. Wedge one of the remaining offcuts of the half-sections of pool noodles into the umbrella base pipe. Wedge your galvanised steel pipe into the umbrella base and tighten the side screw so that it is nice and tight and there is no sideways movement in the galvanised pipe. The pipe should reach roughly to your hip.
  3. Screw the Kewlus Spring onto the galvanised pipe in a clockwise direction so that it overlaps the pipe by one inch. Tape around the connection with duct tape for safety.
  4. Screw your PVC pipe with your speed ball into the the top of the Kewlus Spring, also overlapping by one inch. Tape the connection with duct tape for safety.
Good luck making it and hope you enjoy!