Jrc

Hi Started 3d printing all went well until the 1st few layers unstuck from the surface bed ,the printer carried on printing but the layers were just moving around lose holding on to the nozzzle of the printer ,until I pulled the plug,how do I keep it sticking to the bed and not come unstuck, I printed the free sample that came with the the printer went excellent start to finish built up the layer took about 1hr 15 ,mine just doesn’t want to stcik to the bed can anyone help please!