How do you know???

EGropp

How do you know if the print issues you are seeing are from a hot end that is not up to the task, or if your slicer isn’t doing well??
I have been fighting this printer from day 1.. until now it’s mostly been setup and learning issues, I have been able to print several small items (knowing that they are not quite right), but I have done all of the calibrations and everything seems to be correct. It seems that most every part I print requires a bit of fiddling with settings to make it print correct, but this is crazy.
I have been trying to print a p-38 from 3-d labs and have limited success at best.
For some reason now the retraction settings are off again when they appeared to be correct.
I have gone over the build of this printer several times and I am just not getting something right.
This printer is an he3d ei3 triple extruded (Bowden setup) with 2 of the extruders disabled. Looking at the hot end, the brass nozzle has Teflon tape on the threads as does the heat break tube. I don’t get jams, but I have a heck of a time with stringing, blobs and such.
At what point do I say heck with this printer and spend more $$$ to buy something different, and what would I even buy? It seems that all printers have challenges to be deal with..

Sorry to rant here, it I am looking for ideas to get this to print right. And the question is... how do you know where the issues are so they can be addressed?
I have thought about putting an e3d v6 hot end on this, but if my issue is my slicer (current version of cura, then a new hot end may not fix anything. And if I go with their suggestion of buying the $150 software and the hot end is the issue, I am still not printing...

Help please..!!!

Repetier

First bowden is always a bit of extra problem. It is more like a long spring which means to remove the pressure from the nozzle you need to retract much more then on a direct extruder. I have a good bowden system only requiring 2-3mm retract and a bad one requiring 7mm. Direct extruders hardly need 1mm in comparison. Now if you have many small parts like dots you go over same filament several times. If extruder drive has much pressure this can flatten the filament. I even managed it to flatten it enough that it did not fit inside the tube. This is more a 3mm filament problem as 1.75mm extrudes much more so repetitons are less. The big retracts also make it impossible to use advance to reduce the blobs in edges where you get slower and then faster. And they are even more prominent due to the spring effect. Solutions here are using higher accelerations and jerks I guess. As long as speed stays constant for a while the quality will be good. Meaning if you can handle jerk 30 and print visible outside perimeter with 30-40mm/s you should get a much better outside finish then when printing 80mm/s. The faster you print the worser the bowden effect gets. Use speed for infill that is not visible, but not top/bottom layers. Here reduce speed for better quality.
Stringing happens on some materials more then others. For materials normally not stringing you net to remove the nozzle pressure, so find out how much you need to retract and how fast you can do it reliable. If motor losses steps or filament slips you win nothing, only defects and blobs. So you need to learn limits of your system and configure slicer to only go up the limits.