I have a problem with the Monkey rail. when the motor is activated and the Monkey goes down, after a little run, it makes noise, it grinds horribly. Not always, from time to time. The pin is new and I do not master the hardware aspects yet. I first thought that, when the assembly enters into the wooden part, it touches the wood when gliding. But no, it is a metallic noise.
Because I do not want to put grease everywhere, and it might not help, I would be glad if you can help with this.