Firmware 1.18 Beta Bug

Hi Peopoly

I have come across a bug in the 1.18 beta firmware while doing a dummy print of the corner test (No buildplate and no resin in the vat)

I have PM Follow set to 0. However, the Z axis does not lift at layer change except by the layer height.

It is not clear how the M codes are supposed to work, particularly the M1004 command. I have tried using it, and it makes no difference. Please could you explain their usage in detail.

I have also tried adding the following in the gcode above each layer change:

G91
G0 Z5
G90

But this causes some strange behaviour:

At layer change 0 -> 1 it lifts the Z by 5mm during the peel movement but does not lower it again
From layer 1 to 21, there are only the usual layer height movements at the bottom of the peel movement on layer changes
From layer change 21 -> 22 and onwards, the Z axis moves down by 5mm on the downward peel movement, then back up on the upward peel movement on each layer change.

M codes are sequential. they only represent single movement. g91 g90 is not recognized. g0 z5 is layer change to 5mm and continue to next command. I think it would be best if we give you example codes. you don’t want layer change because that set the

To move up and move down.

you need to pause first,
use m code to move up
uthe set pause time
then set m code to move to back to position
then resume printing

the entire motion is broken down in the smallest steps possible. this is how you can

this is like an linux command where you can chain a bunch together

Nope. Wrong.

We’ve already ascertained that the machine is absolute positioning ONLY.

So consider the following GCode:

;LAYER:0
G91 ; Set to relative positioning, but we know that this is ignored, so has no effect
G0 Z5 ; What we want is for Z to move up by 5mm, but it moves to position 5
G90 ; Set to absolute  positioning, but we know that this is ignored, so has no effect
G0 F18000 X12.376 Y13.47 Z0.1 ; moves Z to absolute position 0.1mm while doing a PM 

..... Lots of GCode for layer 0 .....

;LAYER:1
G91 ; Set to relative positioning, but we know that this is ignored, so has no effect
G0 Z5 ; What we want is for Z to move up by 5mm, but it moves to position 5
G90 ; Set to absolute  positioning, but we know that this is ignored, so has no effect
G0 X12.376 Y13.47 Z0.2 ; moves Z to absolute position 0.2mm while doing a PM

..... Lots of GCode for layers 1 to 21 

;LAYER:22
G91 ; Set to relative positioning, but we know that this is ignored, so has no effect
G0 Z5 ; What we want is for Z to move up by 5mm, but it moves to position 5
G90 ; Set to absolute  positioning, but we know that this is ignored, so has no effect
G0 X13.884 Y14.825 Z2.3 ; moves Z to absolute position 2.3mm while doing a PM

What happens here is as follows:

1. G91 - ignored
2. G0 Z5 - Z moves to absolute position 5mm while doing a PM
3. G90 - ignored
4. G0 F18000 X12.376 Y13.47 Z0.1 - PM, but Z *** DOES NOT *** move to absolute position 0.1mm. In fact, Z does not move at all
5. Layer 0 is printed
6. G91 - ignored
7. G0 Z5 - ignored
8. G90 - ignored
9. G0 X12.376 Y13.47 Z0.2 - PM, and Z moves up by 0.1mm (but not to absolute position 0.2mm)
10. Layers 1 to 21 printed
11. G91 - ignored
12. G0 Z5 - Moves Z *** DOWN *** by 5mm then up by 5mm while doing a PM
13. G90 - ignored
G0 X13.884 Y14.825 Z2.3 - Moves Z up by 0.1mm (But not to absolute position 2.3mm)

Anyway, there are two problems, and you haven’t even mentioned the other one, so again:

Setting Z Follow to 0 is supposed to make the Z axis *** LIFT *** during a PM. It does not. It only moves to the position specifies in the Z part of the G0 command.