Got an issue with a custom-built 3D Printer.
When running a 0.4mm Hotend (E3DV6), all is well and the prints work fine. Typical prints are 0.2 & 0.3mm layer height.
When running an E3D Volcano with a 1.0mm nozzle, I get a massively overextruded first layer, running at 0.8mm layers. This also happens at 0.5mm or anything else I pick.
If I manually reduce the flow rate to 0.75, the first layer comes out fine. I then have to return it to 1.0 in order for the print to finish properly.
I've checked the Z Height with gauges and all is well, so I know that's not it. Something is up with the way that the first layer GCode is generated.
I've even manually inserted M221 S75 for the first layer, and M221 S100 at the beginning of the second to verify this behavior without me present.
This did not happen with MC 1.7.5, however I have been unable to slice anything (Matterslice crashes) when trying to revert to MC 1.7.5, so I've been forced back to MC 2.0.
Am I missing something, or is this a bug?