Introduction: Porta-Leash: Wearable Pocket Sized Retracting Leash

About: Hi I'm Michael! I love all things Science, Engineering, & 3D Printing. If you've enjoyed my work then I've love to hear from you!

The DIY 'Porta-Leash' is Wearable Pocket Sized Retracting Pet Leash! It is small enough to clip onto your pet's collar or onto your belt in an unobtrusive way!

I designed this so I always have something at hand to control my dog with. Honestly, I often forget his big leash and a short walk turns into a long one, and I end up needing a leash to comply with the law or not scare people.

-Its compactness & clip lend it well to storing it many places that you could not store a normal leash, like on your pet's collar, on a belt, in a small drawer, glovebox, or purse.

-Uses a 40" coated braided steel cable and nickel plated steel encased retractable cord reel. (Note- A modification to the reel itself IS necessary to make it strong enough for this use! Its a simple build but the mod requires a steady & patient hand or else you can ruin the cord reel!)

-Intended for dogs up to 25 lbs. (Just an estimate. I have not broken one after completing the mod so it can probably work with larger dogs if they are not prone to lunging or tuging at full strength.)

NOTE: If you don't have a 3d printer or you down want to do this hack then you can get your own finished porta-leash here:

Step 1: Tools, Materials, STL Files


  • Requires 1x Retractable cord reel
  • 3D Printing filament can be PLA or ABS, no supports required. 3 perimeters all sides top & bottom with 20% infill.
  • Super glue


  • Vice Grips
  • Needle nose pliers
  • Spring clamp
  • Phillips screwdriver (~5mm)

STL Files (attached to this step)

  • I made 2 versions, one with the dog bone cutout as shown in the pictures, and another version with a large round cutout that would allow you to engrave things on the steel cover.

Step 2: Tie a Knot in the Cord on the Key Ring End of the Reel

We will start with this step before opening the reel so you can get a feel for tieing a knot in this tiny little cable.

1. Pull out a foot or so of cable and use a spring clamp to keep it from retracting back into the reel.

2. Remove the key ring from the cable end and then you can push the cable through to access the end.

3. Use needle nose pliers to tie a little knot into the end of the cable to take the stress off the crimp.

UPDATE: Make this a double knot to ensure that it is too thick to get pulled through the hole.

4. Reattach key ring and test with your hands to see if you can pull the cable out. (You should not be able to)

Step 3: Carefully Open the Cord Reel

Similar procedure as before but a little harder this time. Read this entire step and the next step before proceeding!

1. Pull cable all the way out and then let ~4" go back into the reel and use a spring clamp to hold the cable in place.

2. Then remove the single screw on the back of the reel to pop it open.

3. Throw away the clear plastic disc.

4. Use the vice grips to guarantee the spring stays inside the reel while you mess with the knot in the next step.

Notes: >>>>IMPORTANT<<<<<< During this process be very careful not to let the internal spring pop out and unravel or you will never it it back in! But you cannot skip this part. For this hack to work you MUST take apart the cord reel and tie a knot in the cable on each end because the stock ferrule crimps are not very strong and will get pulled out otherwise! But, when knotted the reel becomes very strong!

-The picture show exactly whats inside the reel. We will throw away the clear plastic spacer because it can end up getting caught on the knot we will make. (The spacer is normally used for water resistance & friction reduction, but our knot takes up extra space inside so we have to remove it.)

Step 4: Tie a Knot in the Cord Inside the Reel

1. Pull that 4" of cable into the reel to give yourself some slack and then tie a little knot into this end of the cable right next to the crimp again. Use your pliers to pull the knot tight! (Cut off excess if necessary)

2. Jam the cable back into the reel. (When you jam it all back in, if you have trouble getting the case to shut with the cable so close to the spring then you can cut off the crimped end since its no longer doing anything. Just make sure the knot cant come undone.)

3. Optional: At this point I like to take that 40" of cable and wrap it around the spool an additional time in the same direction it was originally wrapped. This extra wrap will end up pulling the spring a bit tighter than the manufacturer intended but it guarantees that it will roll all the way back up without getting stuck and leaving like 2" dangling.

4. Reassemble the case lid. (remember, dont use the clear plastic disc because it takes up too much room with the new knot we just added.)

5. (See next step before putting the final screw back in. )

Step 5: Glue It Shut, Press Into Housing, Enjoy!

1. Put a drop of super glue on the screw threads before screwing it back into the spool. The screw type they used along with the plastic inside the spool arent designed to last as noted by many reviewers on amazon. This glue guarantees the screw wont back out on its own!

2. Notice in the image how I rotated the clip 90 degrees from its factory position. Normally the case would keep this clip from rotating but we want it positioned our way for usability. So use super glue on the bottom of the clip to hold it in place along with the screw.

3. With the spool reassembled, all thats left to do is press it into the 3D printed case! I like to add a couple drops of super glue inside the plastic rim to guarantee the reel doesnt pop out.

Thats all! I hope it goes smoothly for you, because I broke about 3 reels before I figured all this out! :)

If you enjoyed reading about this then please take a moment to vote for this project in the Instructables Pets Challenge!

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