Mobile base for multi-size spools

myminifactory

I want to create something straightforward. I know that using rollers is an option, and they'll likely produce better results, but I'd like to design this from scratch using 3D printing. The concept revolves around building a compact base that can be mounted along the edge of your spool holder. Since I don't have access to specific measurements of your setup, consider this idea a starting point only. The goal is to create a base with rails that allow you to position the rollers according to the size of the spool. I'm aware that the bed will need to support a significant amount of weight for an extended period, but without knowing the exact dimensions of the wood or the depth of the border, this design represents my best attempt so far. I was thinking about incorporating a screw into the bottom part of the base, but I'm still learning 123D and found it challenging to add screws to the design.