Looping

looping portion of a horizontal strut is stretched out of position during printing how to identify looping can be diagnosed as follows looping occurs on struts that are running horizontal, or parallel to the platform, during printing the defect appears at the center of the strut's span looping appears as though part of the strut has been pulled away from the rest of the strut, leaving a gap minor cases of looping may appear as a bump on the strut fanging docid\ zqdgujoitnihiqplrqdvt and pillowing docid\ sojjs8etssqi8gguqitlz are defects that arise from the same issue but appear at different locations or features at strut nodes or surfaces, respectively cause inconclusive cause inconclusive cause inconclusive minor looping troubleshooting it is recommended that you review all the possible solutions before taking action to ensure you are pursuing the best course of action if the best course of action is not apparent, try the troubleshooting options in the order listed refer part defects for more tips print preparation or part design adjustments the following solutions will address print or part related causes of the defects choose among the suggested actions below and select the best approach for your application usually only one type of adjustment is needed orientation reorient the lattice to minimize the length of horizontal struts supports may be needed with a new orientation orientation design add struts to provide more structure at the problematic horizontal struts the performance of the lattice will change design print plan adjustments reference print plan adjustments for guidance on the following parameters 1 pump up parameters pump height parameters minimum pump height minimum distance from peak distance from peak multiplier platform speed parameters motor up speed 3 pump down parameters platform speed parameters motor down speed if problems persist, please reach out to carbon support explanation & causes explanation looping occurs in a lattice when a portion of a horizontal strut is stretched out of position during printing because of how the slicing plays out over the lattice geometry, only a thin portion of this horizontal strut is cured before the next slice captures more of the strut this makes the affected partial strut a thin, unsupported overhang which is therefore weak during the pump up stage while the platform moves up, the weak partial strut is temporarily held in place by the surface tension of the dead zone, pulling it out of shape before the tension is broken when the platform moves back down, the strut is even weaker in its stretched out shape, leaving it susceptible to be pushed in the other direction under the pump down forces this is the position the malformed partial strut stays in when the next slice cures, leaving it to appear disconnected from the rest of the strut this defect usually occurs with elastomeric resins that are soft and pliable during printing reference dls printer dynamics docid\ u7xyytjydp3bvsyy2qkcu for more information on the stages of printing a slice z dimensions for pump height and slice thickness are exaggerated in the diagrams below for visibility lattice sliced to capture a portion of a horizontal strutlooping on a printing slice causes print preparation or part design how the part is oriented , supported , or designed is causing the defect print preparation or part design cause root issue problem why defect presents oriented part is oriented to have longer struts printing horizontally (relative to platform) horizontal struts may be sliced to have thin partial struts that are susceptible to looping designed lattice is designed to have longer struts short struts are less likely to be weak even when sliced to have partial horizontal struts print plan adjustments print plan adjustments print plan adjustments adjust the print plan to optimize mid to high volume production and/or address part defects in doing so, adjustment may both prevent or cause defects below are adjustments that can cause this defect printing stage parameter type type of adjustment why defect presents 1 pump up pump height increase increase increased pump height provides more space for the weak partial strut to be stretched out of shape 1 pump up platform speed increase increase increased motor up speed provides less time for the weak partial strut to break from the dead zone surface tension while also increasing suction forces 3 pump down platform speed increase increase increased motor down speed increases the pump down forces that push the weak, stretched strut out of position