So I sort of disappeared for a while, it has been about 2 years since I have posted anything but I have been working on and off on the machine and I did eventually finish it. But before I finished it, Joshua Updyke ran a class in Mexico that built a version of the machine. They has some success, but I am not sure they got it fully running in the little time they had to build it (I think it was a week). Here is link to some pictures they took during the class.
Then a friend of mine at work suggested I make one for a friend of his who was just getting started in DIY CNC. Life was hectic for a while so it took me a few months to finish assembling my machine and then I tried to quickly cut out the pieces for Paul’s machine. Well apparently my machine was not quite square, so the new machine had some issues with squareness and overall Paul was unhappy with it. Beside the squareness issue it also had a lot more flex than he was willing to deal with, it was hard to adjust the bearing tension and a number of other things… he did a number of modifications and managed to get a machine that while not perfect works for him. Paul builds quality stuff for a living and expects/needs his tools to work well, were as I build things to play with as a hobby and am happy if they work sort of well so part of the issue is one of expectations.
While this was going on I started working on a hopefully more robust 4×8 machine for Paul based on some other ideas I had, and we spent a number of Sundays working on it before I got busy with personal stuff and then winter set in. In the meantime Paul was using the 2×4 machine and mentioned that we was getting a lot of wear on the gas pipe rails, so I started thinking about other rail and bearing designs with the goal of using a better rail material, simplifying the bearing construction and allowing for easier tension adjustments.