Support problems recently

neighbord · April 2

I have recently been having failed prints, which I believe are a problem with supports. Some time ago I printed the same model with no problems. I apologise if the following is too much info, or too wordy.

I am running Cura 5.6 on Linux Mint. My printer is a Creality Ender 3 v2 with a bunch of upgrades, running Jyers firmware. Upgrades that are NOT recent include a Micro Swiss direct drive extruder, dual z-axes, heavier levelling springs, and a BL Touch levelling probe. These were in place when the model printed successfully last fall.

A couple of weeks ago, all of my prints began to fail. I had not noticed that my hot end was totally covered in melted filament. No prints got knocked over. I believe the cause was that I neglected to properly heat tighten both the thermal break and the nozzle. The melted filament appeared to have leaked up through the heat block of the hot end. I was in a hurry, so instead of trying to clean up the melted mess I purchased and installed: an upgraded copper heat block, a titanium thermal break, a thermistor, and a heater cartridge. The new heater cartridge is 60w instead of the old 40w. I PID tuned the hot end for the new cartridge.

I also replaced the glass build surface with a magnetic PEI one, which works great.

The successful prints last fall were done with Cura 5.5. The failed prints were sliced with Cura 5.6

Prints now MOSTLY work, bed adhesion is good, layers look good. The print fails at one or two spots where the model is a bit delicate.

I am printing with generic PETG at nozzle temp 240 degrees, bed temp 70 degrees.

In the first screenshot, the black arrow shows two tabs that are meant to fit into a 2020 aluminum extrusion. The bottom edge of these always falls off, as though there is not support. The second screenshot shows the support. The next two are of my support settings. The last one is a picture of the failed print, with the bits of the tabs having fallen off or never adhered.

I frankly do not have a good understanding of the support parameters. Any help is appreciated, TIA.

Slashee_the_Cow · April 3

If I had to guess it's that the Support X/Y Distance is preventing the support from getting close enough.

If you could post your Cura project file (.3mf, in Cura get it ready to print then go to File > Save Project) then we could have a closer look and play around with the settings to see if we can find something that works.

neighbord · April 4

Thanks, I will post the project file when I'm back home & can access the computer.

neighbord · April 4

Here is my project file. Thanks for the help.

CE3E3V2_y axis rod holder left.3mf

Edited April 4 by neighbord

Slashee_the_Cow · April 5

If you set Support > Support X/Y Distance to 0.4mm, it does support the whole thing:

It's just that the gap between the sticking out bit and main body is small enough that any higher gap won't fit in there. The problem with setting the support distance to that is that not only is it harder to remove, but you get a lot more of it than you need:

Fortunately these things can be targeted: create a support blocker, move and resize it to fill the area - doesn't matter if it's a little bit bigger on the X and Z axes as it needs to be, but thanks to support horizontal expansion needs to be a little bit smaller on the Y axis:

Now with the blocker selected open the Per Model Settings image.png.69889f4bc1b4bb15290e72991dcee96f.png on the toolbar and turn it into the third option (Modify settings for overlaps) :

Click the box that says Infill mesh only and change it to Cutting Mesh:

image.png.503142e0fe00e277ba165fb7394e616f.png

Click Select settings and in the box that comes up search for the Support X/Y Distance setting and check that, then click Close in the bottom right: