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6.5.
Printing Small Parts
Theory
With small parts and short layer times, excess heat may build up in the part and prevent the plastic from solidifying
adequately before the next layer is laid down. This will result in poor output quality and in extreme cases, may
result in failed prints.
While there are automatic cooling settings in Simplify that will control the cooling fan and print head speed, these
techniques can only do so much.
In Practice
The simplest method to make small parts print well is to print multiples of them, and space them out on the bed.
6.6.
Print Head & Extruder Jams
Extruder system jams can have many causes. We’ll cover the most common, and how to recover from them, here.
You’ll usually see one or more of the following symptoms when there is a problem:
Material stops flowing out of the print head (usually happens first)
The extruder motor skips, usually accompanied by a skipping, chirping, or grinding sound
The extruder continues to turn, but the feed gear chews up the filament
If you experience an extruder or print head jam, you will need to halt the current print, as a jammed extruder
generally does not self-recover. Then you will need to diagnose why the jam occurred, and take corrective actions
to prevent it from occurring again. If you merely clear the jam without diagnosing the root cause, the jam will
likely occur again in short order.
Thermal Jams
Thermal jams primarily occur at the print head, and if not caught can cause a slip or jam at the extruder. Some
common causal chains are below.
1.
Print head temperature too low -> extrusion force is too high -> extruder slips or stops turning
a.
Use correct print head temperature for the material
b.
This can also be caused by using low quality material, particularly ABS.
2.
Print head temperature too high -> heat conducts up filament -> filament swells and locks up in cold
section
a.
Use correct print head temperature for the material
b.
This can also be caused by using low quality material, particularly PLA.
3.
Filament retracted too far at end of print -> molten filament pulled into cold section -> filament solidifies
in shape of cold section -> filament cannot be fed forward or backward, and cannot be melted
a.
Generally occurs if print is manually aborted and user manually retracts filament too far.
b.
To fix, remove the 30mm fan and duct. Manually heat the print head up to 220
o
C and allow it to
sit at temperature for 10-20 minutes. The objective is to allow heat to soak into the cold section;
with the fan removed it will not be pulled away like normal operation. Ideally this heat will
soften the jammed plastic enough that we can push it back down into the print head. To attempt
Summary of Contents for F306 Generation I
Page 7: ...7 4 General Info Hardware 4 1 Machine Overview Figure 5 Front View Figure 6 Side View...
Page 8: ...8 Figure 7 Axes Layout Figure 8 Control Board Detail...
Page 9: ...9 Figure 9 Print Head Detail Figure 10 Extruder Cold End Detail...
Page 18: ...18 Figure 20 Filament Fed Across Hobbed Gear Figure 21 Disengaging the Idler Bar Springs...
Page 57: ...57 In general you should be able to get within 1 of the correct flow rate with 3 trials...
