Customizable wheel for portable equipment - V1

Introduction

This is a wheel I made up to replace the broken ones from my air compressor. It is designed to be mounted with hardware available locally (I used hardware from Lowe's, but dimensions can be adjusted for whatever you find near you). It is designed using 53 degree overhangs, which my printer can handle with no supports, but that can be adjusted as well if you prefer more gentle overhangs.

I recommend printing with many walls and printing the tires if your printer can handle TPU. You can see in the images that I cracked the wheel when pulling it over a door threshold, which is what convinced me to go ahead and finish the tire model. These are pretty easy TPU prints, my Ender 3 handled them with 95A TPU no problem.

Dimensions:

• Wheel diameter: 125mm
• Wheel width: 37.26mm
• Wheel offset: 9mm
• Shaft diameter: 13.35mm
• Shaft length: 24.25mm
• Tire diameter: 141mm

Mounting configuration

I designed this wheel to use a 3/8" steel spacer as a shaft. The spacer is fixed in place with a 3/8" bolt and a washer on either end.

Fixing the spacer tightly in place helps bolster the bolt against bending loads and provides a smooth surface for the plastic wheel to rotate against. Alternatively, you could fix the bolt in place and press the spacer into the wheel, allowing the spacer to rotate against the bolt and removing the plastic-on-metal wear.

Parts needed per wheel:

• 1x - 3/8" bolt long enough to fit through the wheel, two washers, the mounting location, and a nylon lock nut.
• 1x - 3/8" x 1/2" x 1" steel spacer
• 2x - 3/8" flat washers
• 1x - 3/8" nylon lock nut

Here you can see the hardware stackup loosely assembled without the wheel in place:

And here the hardware is tightened, and the wheel is installed:

Extendibility and future plans

I included a groove so that a TPU tire can be printed separately and installed securely. Included in the FreeCAD model is a tire model sized to fit around the wheel. I'm still a CAD noob, so I'm sure the model could be simplified and improved, but it's there and the tire has been working for me. I glued my tires on with E-6000 and that seemed to work well, even though they don't recommend use on PET.

There are a couple improvements I'd like to make, primarily that I would like the entire model to be driven by a spreadsheet, and that I would like to offset the tread pattern on the left and right halves of the wheel to reduce noise.

Modifying the model

There are 4 main sketches in the model that can be adjusted to customize the wheel:

• Wheel>Revolution>Sketch defines the wheel dimensions
• Wheel>Pocket>Sketch001 defines the profile and depth of the treads on the wheel
• Tire>Revolution001>Sketch002 defines the thickness and clearance for the tire
• Tire>Pocket001>Sketch003 defines the profile and depth of the treads on the tire

The tire dimensions are driven by the wheel model, so you only need to specify the clearance from the wheel and the thickness of the tire.