My test core xy platform is up and running. Days spent printing the various parts on my slow but accurate and precise shapeoko 3d printer. Then a few hours dissembling the shapeoko 3d printer to scavenge all it parts, like the rails and v-groove wheels. Next step i assembled the platform, it came together easy enough. I few hiccups in my design were particularly the distance between the v-slot wheel mounting hole. This is not a critical dimension, but is important because this dimension effects the v-groove wheel grip on the linear rail. Two out of four v-groove wheels per carraige come with a eccentric nut that allows the user to adjust the position of the v-groove wheel by about plus or minus one millimeter. 3D printed parts shrink a small amount, so for parts that need to have critical dimensions, you have design your 3D models considering that these slight changes will occur. The core xy system worked surprisingly good, its just so much faster then my shapeoko 3d printer. I tested it by basically sticking pen to the x carriage and got it draw using g-code files. Testing how accurately and precisely it drew squares, circles and all sorts of random shapes. It done very well. I had it repeating the same square over and over about a 100 times just see if it was losing steps. No problem for it. Same was done for circles and other shapes. Next i got it to draw large squares measuring 100mm x 100mm. (i coudnt really go bigger as it was drawing on a A4 sheet) A 90 degree set square used to measure if it was truly square and to the human eye it was. Success so far. With various g-code files i ramped the speed in succession: 30mm/sec, 60mm/sec, 90mm/sec, 120mm/sec, 150mm/sec, 200mm/sec. It worked to 120mm/sec without flaw. I couldn’t push it faster. Simply because the pen was taped on and at higher speeds it couldn’t keep up. I tested it with a complicated stickman man drawing which had narrow tight curves which tested how the platform dealt with smaller details at high speed. It could do it successfully to 90mm/sec. I will alot more testing to see if the core xy system is what i want for a 3D printer. I want something reliable and i am not sure yet if it is.