Hello, I have been in the process of finally adding a quick tool change to my Ender 3 pro with the Creality 4.2.2 board so that I can play around with more engraving/CnC. I am only using LightBurn to generate GCode and then just running it through OctoPrint. I recently got my laser working and dialed in thanks to finding this amazing program.
My pen setup doesn’t use a servo and instead relies on the Z control to engage/disengage the pen. I am using relative Z moves only and optimize Z moves is off. In line mode this works as intended the pen will lift and drop on the Z, but fill does no Z lifting and so it is also filling in all the traversal moves. Offset fill is a bit better but it still leaves the traversal line where it should not.
I can see in the GCode that line does use the Z offset commands and fill does not.
I was doing some reading and heard about an upcoming pen mode but was wondering there was another solution for this other than doing some sort of M106 for Z move swaps (I’d rather not have to do this).
Is this an automated changer? Or just a special bracket that allows you to do a no tool swap?
I’m actually more surprised that line lifts Z than I am that fill does not. I don’t see any practical reason why line would lift but fill would not. Unless this is some carryover from CNC operations.
I don’t know of a proper fix for this but I can offer a potential hack/workaround based on the information you provided about line working.
There’s a facility exposed in LightBurn that allows you to actualize the rendered cut path for any given object. It’s accessed from Edit->Convert to cut (debug). You could potentially use this to convert all fill operations to line operations and run the job that way. If all works according to plan you would get your Z lift and LightBurn would get to work with lines.
Setup your design with cut as fill type
Select all relevant elements of the design. Then Edit->Convert to cut
Before doing anything else hit the Delete key. The Convert to cut creates an extra set of objects. Doing delete right away will remove the originals. Or simply move away the original set
Change layer type to line. The converted objects in workspace should continue to look filled
Do whatever other pre-job checks you would normally do
Automated… I wish! That would be great, but no it is just a tool-less swap, Proper Printing’s Quick Tool Change is what I am using and it’s been good so far. (I just found a slim version that doesn’t lose as much Y travel and may switch to that soon)
Yeah I didn’t think it would work either but it did which only served to confuse me with the fill issue. Definitely think it is related to the engraving aspect because fill is only using the M106/107 to activate/deactivate the laser as necessary and doesn’t need a Z move to lift a head out.
This workaround has worked great, the path it takes is a bit odd but I may have to play around with the travel optimization settings. This also gives me a great lead for my next tool-head I will be testing… the Dremel Flex Shaft.