Why does a walking pad get louder over time?
A quick follow up on the belt situation.
The first three sample belts arrived and I tested all of them today. Unfortunately they all showed the same problem. A bit disappointing, but the tests gave me much better insight into what is actually causing it.
The finding that mattered
The samples had different surface textures on both sides, and one clear finding came out of it: we need a smooth surface.
Even a slightly rough texture already creates quite a lot of noise, which is a no go for this product.
That surprised me. I had been thinking about the belt as a durability problem, and it turned out to be a noise problem at the same time. The two are not separate. The surface that wears best is not automatically the surface that runs quietest, and on a machine built around being quiet, the second one wins.
Why walking pads get louder as they age
This is the part that explains something people complain about constantly with electric pads.
A belt surface is not fixed. It wears. A surface that starts smooth develops texture over months of use, and texture is what you hear. On an electric pad there is a motor noise on top of that, but the belt itself contributes more than people assume, and it contributes more every month.
So a pad that was quiet in a review written after two weeks is not the same pad after nine months. That is not the reviewer being dishonest. It is the surface changing.
Which is why I would rather get the material right now than ship something that sounds fine in week one.
Two more on the way
Two more belts are on the way. One is especially interesting because it is made of a harder material. It has a rough surface, but for understanding the material behaviour it should be a really valuable test. I have one or two other ideas as backup as well.
The risks
If none of these work out quickly, the search could drag on.
And if we end up needing a custom belt, one manufacturer said it is possible at our volumes but would take six to eight weeks. With another manufacturer we do not even reach the minimum order quantities.
Is my test rig just too brutal?
Something I noticed: the belts only get dented in three specific spots before they fail. That is odd, and I doubt that would happen with a person walking on it.
There are special pressure measurement films for exactly this kind of test, so I will try to get one and compare the dynamic load from the machine against a similar weight from an actual human. It is possible the machine is simply exaggerating the forces.
That would also fit my observation that I have never had this problem in real use.
When the belt broke · How quiet it actually is · The Office Walker