Over the last few months I've been able to nail down really good settings for the HS and I'm often printing flawlessly at 150mm/s (with shells, supports etc at varying levels of underspeed) with both PLA and ABS using different nozzles (including 0.5mm for fast prints).
My biggest problem is the discrepancy between the time Simplify3D tells me a print is going to take an how much it really takes. My latest print was an 18 hour print according to Simplify3D but actually took closer to 23 hours! That's a huge miscalculation! The time remaining on the screen of the printer while printing is even less accurate because it seems to be calculating the time based on what part of the print it is printing. When I print the infill at a fast speed, the time remaining plummets, but when I print the outside shell at a slow speed, the time remaining balloons! Is there a solution for this?
I will try to explain the reason for this and if anything is unclear in any way please let me know:
1. The time Simplify 3D actually shows is a estimation based on the number of lines the gcode has and the default printing speed which is chosen;
2. Now when the gcode is loaded to the HS the gcode goes through the firmware and the firmware adjusts the speed of the print depending on how many commands the firmware will process;
To be more precise if you have a model which has the shape of a square which is defined by 4 spatial points means 4 commands;
Now the estimation which the firmware will make, will be based on the previous layers and the speed at which they were printed; So for example you will get a estimated printing time of lets say 2 hours;
However when printing if your model has multiple shapes the printing time will change:
The firmware has a buffer of 16 commands which goes in a continuous loop as one command is executed another enters (which is also why the printer will not stop immediately when you pause the print as the buffer has to be emptied). The firmware always checks the first command with the last command and adjusts the speed of the print in order to make sure that all of the loaded 16 commands will be executed properly and at the highest rate possbile but this always changes as one command is run and a new one is received;
So actually the only way you will know for sure how much a print will take is to run the gcode and time the print yourself;
In some cases when a print is quite simple the estimated time will be closer to reality.
So in conclusion there is nothing wrong with the printer it is actually more to do with how Simplify 3D estimates the printing time and how the firmware processes the commands;
Let me know if this explains why the estimation Simplify 3D makes is not accurate.