Hello,
while building the first robot, I noticed the paint scratches easily. To prevent this I started using plastic rings every time. I bought some extra rings in a local store (Brico). As you can see on the picture here, they are thinner and wider than the makeblock ones.
On the left, three makeblock plastic rings, on the right two that I bought locally.
Another pic of makeblock and other plastic rings on the scratched surface of a makeblock beam.
The problem with the ones I bought is that they are too wide, but being thinner is an advantage in some cases.
So the product idea is this: provide plastic rings that are as thin as the ones shown here, and as wide as the ones you provide already. In bags of 100 each please.
If anyone knows of a store in Europe selling such plastic rings, let me know.
greetings rom Antwerp!