Hi.
I am an Engineering student. I need to build a large CNC metal drilling-machine, 6m (240”) long and 2m (80”) wide and high. The machine will have only small forces because it does not need to mill, it only has to be able to drill small locating holes. The accuracy has to be within 0.25mm (0.001”) . We have a very small budget (2500$ US I’m from another country so don’t know how cost compare) so linear guides will be too expletive and need to use a DIY guide method. We thought about using home made V rollers but I’m not sure if the accuracy will be achievable. Anny ideas or other threads or literature that I can check out will be appreciated.
Because of the size the surface will not be machined where the guides need to be fixed. Any advice on minimizing the possibility of miss alignment will also be appreciated.
The machine will only have rails on the one side where it will be driven by a servo motor with encoder. The long axis motion will be done with rack and pinion and the other two axis with screw and nut. The frame will be made from square tubing. Does the over all design sound feasible? This is my first time working with CNC so any advice will be appreciated.