This will get a really big post today. Before assembling I prepared all the parts as you can see on the image on the right. I began to assemble the gantry sideplates. Followed by the gantry itself. I didn't fix the linear guides at this point to be able to adjust them later properly together with the ball screw and Z-Axis. It is crucial the both beams behind the linear guides are absolutely co-planar. Otherwise the guides will not move smoothly. Not very well designed I know. Better would have been to build it out of one part and machine the faces where the rails are fixed. |
Next step was the Z-axis. I reused the ABS parts from my old mill. Not the best choice I realized when the machine was finished. While assembling I also prepared all the cables for the whole machine according to my CAD drawings. I love those mate-n-lok connectors. They were exactly what I was looking for a long time.
The bed followed. I fixed the linear guides directly to the T-slot plate to avoid any misalignment. Compared to my old design with unsupported linear guides. Again, machining both faces would have been way better.
To align the guides parallel to the T-slots I had to make a holder for my dial indicator. It worked as long as I didn't touch anything. I have to improve it for further use. The true horror story started when I tried to screw down the gantry to the linear guides. I realized the two faces where I fixed them were not co-planar. I spent hours fixing this placing thin distance sheets between the linear carriages and the gantry plate.
Aligning is the most important work when building a CNC. Every mistake you make here will have a big impact on your final machine and the parts you make on it. You will never be able to manufacture accurate parts if you didn't align everything properly.
I started with the wiring of bed and gantry after the mechanics where finished more or less. Everything worked as planed. The cable lengths I designed in CAD where correct. Soldering the parallel port connectors was a bit annoying but quickly finished. I tested the wiring before I assembled everything.
Soon after successfully testing everything, the machine was completely assembled and ready for its first use.