A swappable printhead for the UM2. Nice if you want to experiment and have to take the head off often. Don't print in PLA it will warp and the linear bearings will come loose.The small 1,5mm holes are to lock the bearings. Bend a 1,5mm steel rod into a U shape and stick it in. They should not be needed because the bearings should sit firm in the holes.ATTENTION!Unfortunately the printhead is a bit larger then the original, therefore you should change the build space accordingly (Or take care that you don't build anything bigger then 20cm):#define X_MAX_POS 200#define Y_MAX_POS 200