TPU Mallet

Update 3/3/2026: Join my Patreon for commercial use membership: patreon.com/animuL67

Thank you for the support! The model remains free for personal use.

Your maker room isn't complete without this rubber mallet to assist you with your projects. Tap in bushings, bearings, and snap parts together with this weighted design that utilizes 28 US pennies or scale for other coins or materials to add weight to the hammer head. The TPU strikes press in with a lip to keep them secure. The shore 90A material protects the item it strikes while imparting deadblow force and the compact design allows it to fit comfortably in your hand and conveniently in your tool bag.

When I posted this I couldn't find anything like it and now I'm seeing some other options pop up. Thats cool to see because I love inspiring others and giving multiple options to the community. I want to help you make an informed decision on which to print so here is an outline of the key features of this mallet that I think will stand above the rest and the test of time:

Strength: It's a hammer, it has one job to do: hit things. It has to stand up to each and every blow and this is designed with the appropriate wall thicknesses, layer orientation, and overall shape to get the strength where it needs to be without adding too much material that drives up the cost and print time. The layers are parallel to the direction of the strike which means they are reacting the loads in compression which minimizes the chances that the hammer splits along layer lines. If this was printed on its side or upright it would significantly weaken the design with no real benefit.

Another important strength aspect is the overall shape that flares smoothly from the shaft to the head. Sharper corners and notches create structural hot spots and are prone to cracking. Smoother transitions allow the stresses to flow more evenly and not become concentrated. Now, this all isn't to say that its not breakable, its just plastic after all, but it is to say that specific efforts have been made to improve strength.

Weighting: The next and arguable equal important feature of a hammer is weight. But its not just overall weight that matters, its putting the weight where it works that makes the difference so having the weight in the head is the best place to put it. Now, having said that, it wouldn't hurt to weight the handle and a version with a hollow handle could be requested but for now I think this gets the job done. Back to the weight- I chose pennies (or other coins) because they are readily available to most, are heavy as steel, and are cheap. No need to fill with sand than can be messy, isn't as heavy, can cost more, etc- unless you really want to and then, by all means go ahead and fill this with whatever you like. Honestly, I was pretty proud of the idea to use pennies and I look forward to what others come up with using that and similar design approaches.

Ease of manufacture: There are no supports which is why we have the unique shape; the chamfers are for aethetics and comfort but also are a specific angle to avoid any issues when printing with no supports. A tail on the hammer would move away from the flat surface to print on. The penny / coin weight also makes it more convenient to assemble assuming you have them laying around. The TPU strikes push in place with no glue required.

As an avid printer myself for many years I know we love it when we can produce things without having a bill of materials to hunt down or wait for, so I've worked to make this as convenient as possible to produce.

Ergonomics: My background is in designing private jet interiors and one of the things we focus on is human factors in design. Something as simple as the shape and size of a handle can change the comfort or even just the perception of quality and function. I know its simple, but the handle size and shape is no accident, its done specifically for improved grip and feel.

Anyway, try my design, try others that are popping up but know that a lot of original thought went into this design, to come up with a tool that I find useful and hope you do too. Thanks for the support!