Designing a Poop Bag Holder

Not the most elegant of titles, or projects, right? But this was the next stop on my travels with functional 3d printing. The holder we’d been using for our dog begun to tear, and to be honest, was kind of a pain that it attached to the handle. So my next project became coming up with a slightly different design. The goals?

  1. Something that attached to the underside of the leash
  2. Something that didn’t use a clip, which is what broke on ours
  3. Had a way to attach a full “used” bag to the holder so I didn’t have to carry it

So to the drawing board it was. The first design challenge was the toughest, making sure it attached to the underside of the leash, which meant the leash had to slide through it, but also not slide around on the leash. My initial solution was similar to how a strap might go through a buckle, sliding up and down over some pieces as it went through. A cap would slide into a slot near the top to hold the roll in place.

A relatively quick print, and here was the result:

Here’s where the fun of the prototyping process comes in. The piece was a total failure.

  1. The leash was a pain to thread through, and the tolerances were too tight
  2. The cap design didn’t work well and ended up breaking when sliding it on
  3. The thing was really bulky and kind of heavy

So with that failure, I was back at the drawing board, but that’s the fun of owning a printer, I can prototype quickly. My wife actually came up the solution to #1 and #2. Instead of trying to thread the leash completely through, the pieces going across the track wouldn’t go all the way across. Instead, there’d be alternating breaks to allow the leash to be inserted in through the side. It was also her idea to have the cap swing on a pin, with the leash going through the top as well, helping lock it in place. #3 was really the easiest, just round off the entire model and make it less thick. Some quick interactions and this is what the design looked like.

I quickly threw this over to MODO to add my dog’s name (Kona) and the UO logo (we’re Ducks) onto it before printing it out. Some sanding, finishing, and painting later, and this is what we’ve got.

It could’ve printer better but all in all, I’m pretty happy with how this turned out. It looks fine, it’s worked great, and doesn’t slide on the leash. Not a glorious product, but still a win. You can download the STL file for this here: Poop bag holder STL Any questions about it, feel free to leave them in the comments.