Solved How to calibrate Z axis motion

So I got a new power supply and now I can print the MatterControl calibration ring all the way through. The X and Y motions are perfect, and the extruder is pushing out correct amounts of plastic. The first layer is beautiful and the second is ok, but then the nozzle goes a bit higher with each layer so that by the time it gets to the top layer it is about 2 mm above the ring and it makes very pretty waves as the plastic lays down.

I am using T-glase with the temp at 238, bed at 60, physical nozzle is 0.4 but I followed the guidelines and set that to 0.5 in the settings. I also set layer height to .4 with first layer at .3. Perimeters: 1.2; top and bottom 1.2 mm.
Infill 100%, Travel 150 mm/sec, all others 16mm/sec. First layer speed 30% (I assume of 16). Filament 1.75mm (I don't think retraction applies for the ring, but the settings were 0.5mm lift, 1mm move, 20mm min).

I did not touch any of the G code, so the default startup is:
G28 X0 Y0 Z0;
G1 Z5 F5000;
M109 S[temperature];
G28 X0 Y0 Z0;
G29;

The bed levelling works great - the first layer is perfect. There are supposed to be 4 layers of material, and it should be 1.5 high (.3 + 3*0.4). But the last layer is being printed at 3 or more.

Since X and Y are perfect (the ring is 14 cm in diameter and is closer to round than I can measure) I would think Z should be good too. Do I have a setting screwed up, or do I have to change something so it moves Z correctly?
Dr. mike

 

It's a brand new R1+. I changed the software using the Firmware download to change the baud rate. I would not be surprised - there is a note on that web page to NOT use it to upgrade the R1+. All I changed was the baud rate - so it should be easy enough to change anything else. I just need to know what bits to flip, otherwise I'll make things a lot worse!

Thanks!

Edit: in Configuration.h there is a line DEFAULT_AXIS_STEP_PER_UNIT {80, 80, 2560, 723.38}
Is that what I need to change?

 

Excellent, thanks! I just have to make sure I change just the baud rate. I will give it a shot.

 

Perfection at last!! The calibration ring is perfectly round and solid and the plastic has the optical properties I'm looking for.
Thanks to everyone - I really appreciate it!
Dr. mike