Hub Cap for Honda lawn mower (model HRB 475)

As our lawn mower was missing one of its hub caps for quite a while now and I recently got into 3d printing, I decided to model a replacement part.

The hub cap is specifically modeled based on the measurements taken off of the Honda HRB 475 model, but should at least fit other Honda lawn mowers with the same tire style (diameter of the hub cap is 134mm).

I tested different filaments and ways to print this. Here, I learned that PLA prints easy, but is too brittle and the “gripper arms” easily break when hit or pushed alongside bed borders and alike - as you can see on the other hub caps, they get quite some beating. Eventually, I ended up printing it with TPU. It is a little less stiff than the original cap, but a difference is not visible and by that, it is a lot more rugged than the original hub caps. You can try printing it with PETG though, as it is less brittle and may withstand it better than PLA.

So that you have a choice, I included 2 different types: one with relief holes for PETG, PLA or other stiffer filaments (version 2.1), and another one without relief holes for TPU (version 2.2). Each model fits well over the receiving ridge of the tire and is securely attached.

Picture #5 shows a close up of the tire style, so you can see whether the model will fit your on your lawn mower as well. The original part is shown in pictures 6 and 7.

As I learned during several test prints, the dome part of the cap prints and looks way nicer when not directly placed on the print bed, but rather printed as the top layer. This takes longer to print (especially with TPU) and requires supports, but the result is worth it. To allow you to choose, both .stl files show the model standing upright, so you simply have to select the face you want laying on the print bed. Also included are the f3d files for both types, so that you can tailor it specifically to your needs in case you have a different tire style. Please note that you can influence stiffness of the TPU model through different filament manufacturers and the number of perimeters.

Although you can see the difference as the replacement cap neither has any scuffs on it, nor is it slightly yellowish from the cut grass yet, but it looks way better than before regardless.

Print time in PLA with the outside cap laying on the print bed was about 7 hrs, print time in TPU with supports for optimal result was about 23 hrs.

Happy printing, and curious to see your makes.