Jordan Sipsip left a comment which among other things asked if I had noticed any sagging of the rails. I really had not noticed any issues with the rails flexing under the weight of the gantry, but I decided to do a quick test. I stacked a number of pieces of wood under the center of the longest rail so that they were almost/barely touching the rail.
I then moved the gantry to the edge of the stack and attempted to remove the top most piece of wood… it slid out without any binding at all. While not very scientific, I think this demonstrates the minimal flexing issues I have observed up to this point, and bodes well for the future.
I also replied to Jordan that I had originally started working on a different design that might work better for him if sagging was a concern. This was/is the starting point of my bag of parts kit. I had started out designing pipe guides that would slide over the edge of a board to serve as the rails, and even cut out a full set for prototyping before I veered off onto the current concept. I plan on coming back to this concept after the current machine is done, in fact I think I could probably build a variant of the current machine using this rail design with minimal effort. In the meantime thought I would share the idea, so I found the pieces in the garage and took a few pictures.
If this idea looks interesting please feel free to run with it, I won’t be offended 🙂 Just be aware that I will be venturing down this path as well, so you might have some competition.