Quote Originally Posted by wirlybird View Post
QIDI TEch-1 extruder temp issue. My printer seems to have developed an issue maintaining the extruder temp. Say I set it at 200 for a print. It heats ok but a little while after the print has started the temp registers as much as 15 degrees less. S3D and the printer display both agree. After a long time, let's say 20 minutes into the hour and a half print the temp slowly starts to inch up. Over the 90 minutes the temp is barely able to get back to the target temp.

Any ideas?
If we assume the thermocouple channel is reading back the correct value, and that the heater control electronics is functioning properly, then there must be a reason the heater is not transferring enough heat into the hot end to achieve the target temperature. Either something is sucking the heat out, or something is keeping you from pushing enough in. 1.) Have you changed the thermal wrapper or added fans, or made some mechanical alteration that would increase the thermal mass or thermal conduction out of the hot end? 2.) Have you done anything that might reduce the heat conduction path from the heater cartridge into the hot end? Like adding a sleeve, or some layer of non-conductive crud between the heater and the block. Or maybe bad electrical connections to the heater element or possibly a bad heater element: Measuring the two heater cartridges on my QiDi they both appear to be about 14.1 ohms across the unplugged cartridge at room temperature.