I designed this belt clamp to clip under the standard plastic arm mounts on the carriage. It simplifies installation, removes weight, and makes it easier to customize your carriages.

They're small, so printing several of them on a plate is not a bad idea. You'll need 3. I've uploaded the original DesignSpark file in case you need to tweak the dimensions for your machine.

Attribution - Creative Commons

Rostock, belt, clamp, carriage, tricktrucks