I have a suggestion for improving Cura with a new Plugin, could call it Intro line

[HomeMaker 0]

I have a suggestion for improving Cura with a new Plugin?

Problem:
In my start code I entered 2 straight lines, each 30cm long, on the front of the print bed for nozzle cleaning. The slightly raised nozzle then moves without extruding to print the brim (or skirt or raft or object). It happens that the first millimeters of the brim/raft/skirt/object do not adhere correctly and are taken away by the nozzle and the first layer becomes unclean.

My solution:
After the 2 cleaning lines from the start code, I print a line directly to the beginning of the brim/raft/skirt/object, so that the first layer adheres from the start of the Brim. I call this line >INTRO-Line<.

Would anyone find this helpful and can implement this option in a Cura or in a Plugin?

See Picture in the Attachment!

[Slashee_the_Cow 344]

Here's the feature request form. It might also be possible with a post-processing script (much easier than a plugin).

[Cuq 205]

Agree a postprocessing script can do this job.

 

But what happen's if you have have two or more parts on the bed ? 

And if you have some inner boundaries in your models ?

 

[HomeMaker 0]

When using a brim or skirt, Cura always starts the printing process at the front left, i.e. at the shortest distance from the origin (as long as the origin is x=0/y=0 at the front left). This means there is no intersection. The plugin/script would have to be designed in such a way that it also takes all other cases into account and avoids intersections.

[Slashee_the_Cow 344]

Take this One at a Time print as an example:

For whatever reason (I'm not sure sure if anyone's figured out any rhyme or reason to how Cura orders models it prints in this mode) it's decided to do the one further away from the origin first. Your "intro line" would run straight under the second model and cause a scar when it prints (not to mention negatively affect the adhesion due to being on an uneven surface).

 

Is this avoidable: probably yes, but it'd be a major hassle. A script (or plugin) would have to take into account the footprint of every model on the bed (including brim/skirt) and then plot a route to the first brim/skirt around all of them which involves the shallowest angle changes possible (since a corner is where a single line is most likely to lose adhesion). Or, the simple way out, just disable itself in one at a time mode.

 

Is this an uncommon situation I concocted mostly to prove a point: probably yes, but I'm trying to demonstrate there's no one-size-fits-all solution to this problem.

 

Although IMO what it ultimately boils down to: if you need this for adhesion, you're overcomplicating things. Figure out how to get your adhesion better by changing print settings rather than relying on something like this as a crutch.

[jaysenodell 17]

2 hours ago, Slashee_the_Cow said:

Although IMO what it ultimately boils down to: if you need this for adhesion, you're overcomplicating things. Figure out how to get your adhesion better by changing print settings rather than relying on something like this as a crutch.

This is the answer. Slashee help me work through this exact issue when I started 3D printing and it 100% was not having the setup of hardware and first layer dialed in. The secret for me:

1. Get initial hardware Z offset to 0.075 on the high side and 0.130 on the low (corners v center of bed)

2. Run ABL after setting Z and any time spring plate was removed. 
3. Increase initial layer line width to 105-125% depending on material (color sensitivity with my PLA just experimenting with PETG this weekend). 
4. slow down initial layer to 25mm/sec. 
 

May not work for you but this has eliminated my need for any nonsense to get junk to stick to the bed. Load the models, slice, send to octo, wait for the notification that it’s done. If I see layer adhesion issues I know something else has gone wrong. 

[Slashee_the_Cow 344]

12 minutes ago, jaysenodell said:

3. Increase initial layer line width to 105-125% depending on material (color sensitivity with my PLA just experimenting with PETG this weekend). 

4. slow down initial layer to 25mm/sec. 

The targeted approach. Nice that you've figured out exactly what you need to change.

 

When it comes to print settings, I usually go for the "shoot first and don't bother asking questions because it worked" school of initial layer adhesion:

• Quality > Initial Layer Line Width 150%
• Quality > Initial Layer Height about 1.5x what I'm using, depending on what my nozzle is capable of, I usually print 0.2mm layers so I use a 0.3mm initial layer
• Material > Build Plate Temperature Initial Layer to 5° hotter than the rest of the print
• Material > Initial Layer Flow to 105%
• Speed > Initial Layer Print Speed down to 25mm/s
• Speed > Initial Layer Travel Speed also down to 25mm/s because I don't want it zooming off with something that hasn't set yet
• Cooling > Initial Fan Speed at 0%, regular speed by layer 4 (for materials which need to be cooled)

But before you bother with all these settings, make sure you double or preferably triple check that your bed is level and your Z offset is correct.