Extrusion Issues

[candts 0]

Howdy!

 

Our research lab has an Ultimaker Original 3D printer with the extruder upgrade. Recently we have been experiencing several issues during extrusion. While fabricating the desired part, the printer will begin printing the part with a tufted appearance. In some cases the printer head will continue moving, while in other cases the printer head will stop on the part. We have tried cleaning the extruder nozzle as well as ensuring that the feed of the material is working properly; however, this has not fixed the issue. After performing such procedures and restarting the part it will begin laying the material down correctly, but will eventually fail in the same way. It seems to fail at different points on each part. It was noticed that more complex parts seemed to fail earlier than simpler parts; however, such association was not fully verified. To further this theory a small block was printed and this experienced no problems. Thanks so much for your assistance!