How To Make a Boxing Cobra Punching Bag Using the Kewlus Spring

Cobra Punching Bag DIY


Make your own Cobra Punching Bag at home that is faster than some of the top brands on the market at just a fraction of the cost.

To make it super easy I designed and produced a custom spring specifically for this purpose. I made it so that you can simply screw it onto a 3/4 inch galvanised steel pipe.

If you have any questions please put them in the comments below and I'll respond as soon as I can. Also please share your thoughts and experience with others here if you make one.

Items You'll Need:

  1. Kewlus Spring (KS9) - purchase here:
  2. Base pipe: galvanised 3/4 inch pipe (1.05 inches outer diameter) the length of roughly half your height. I used a 3 foot long pipe for my height (I'm 6ft tall). The 3/4 inch pipe has an outer diameter that is 1.05 inches. The spring is designed to fit perfectly onto this pipe. You can also combine sections of pipe using a coupling, for example 2ft section and 1ft section to allow reduction in height for a shorter person.
  3. Umbrella base - for indoors I recommend a concrete one. For outdoors a water-filled umbrella base would be ok. You can also make your own Base/Stand to save some coin: I highly recommend making your own stand because the galvanised pipe can be simply screwed into it - great for easy assembly and also great for putting it away when not in use.
  4. Roll of duct tape. Nothing fancy, just get a cheap one.
  5. Length of 3/4 inch PVC pipe - you'll need 2 foot length.
  6. One or two pool noodles. One might be enough, but if you can, get a couple. The diameter of the hole should be less than 1 inch so that it fits tightly onto the 3/4 inch PVC pipe. As an alternative you can also use pipe insulation foam which is similar to a pool noodle but just comes in black colour.

6-Step Instructions:

  1. Cut a section of pool noodle to use of your punching bar base. I recommend about a foot. Take another section of pool noodle (roughly 18 inches) and split it lengthwise. 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 speed ball.
  2. Take the remaining section of the pool noodle and slice it in half lengthwise using a knife. Wrap one of the half-sections around the punching bar, forming a circular shape. Cut off the access and tape around it with duct tape. This is your target.
  3. Setup your umbrella base by removing 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.
  4. 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.
  5. Measure off and cut 20 inches of 3/4 inch PVC pipe. Screw that into the top of the Kewlus Spring, also overlapping by one inch. Tape the connection with duct tape for safety.
  6. Insert the punching bar onto the PVC pipe.
Good luck making it and hope you enjoy! If you have any questions feel free to ask them in the comments below.

Related Videos:

How To Make a Cobra Punching Bag Using The Kewlus Spring (22 Nov 2020) -
How To Make a Boxing Cobra Punching bag using the Kewlus Spring (17 Oct 2020) -
How To Make a Speed Bag Cobra Punching Bag Top -
DIY Base/Stand V2 - for the Boxing Cobra Bag (10 Aug 2020) -


  1. Will the spring work on 3/4 x3 foot with 1.05 outer diameter?
    Can’t find pipe with 1 outer?

  2. is the spring delivery free for france even wiyh the taxes ? (sorry for my english btw)

    1. Hi, do you have an idea of the delivery time to France? Thks

    2. Currently the estimated 2-4 weeks to France. Soon I will have distribution out of Amazon UK, so will be quicker then. Stay tuned!

  3. Hi i am portuguese and i am 5´8, which base pipe should i use ?

    1. Get a 3/4 inch pipe (outer diameter 1.05 inches) that is half your height in length, so roughly 3 foot long would be ideal.

  4. Is the spring threaded or does it slide on the threaded pipe?

    1. The spring has no thread. It opens up as you twist it clockwise, so twist it clockwise to slide it on. You also twist it clockwise to slide it off.

  5. Replies
    1. Yes, it's free shipping worldwide! For details please see:

  6. Hey I can only find a 20mm pipe, is that the right one ?

  7. I ordered the spring, got the required pipes and concrete base, and with it all put together, I'm not getting the flexible bounce back action that you get with the one from your video. It seems too stiff and it's more of the whole pole moving than just the top part moving. What would you think I've done wrong?

    1. Thanks for the purchase. OK, the most important thing is to ensure your base pipe does not move or is as sturdy as possible. The base setup is key to the whole thing. I recommend using a 1 inch flange and a 1 inch pipe at the bottom, and then attach a short 3/4 inch pipe onto that using a reducing coupling. Watch this video:


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