Different Print Speed

[3D-Druck22 0]

Hello,

i have the following problem:

I set the Print speed overall at 100 mm/s.

The Brim ist printed with that speed and the first two layers as well.

But then it slows down to an unknown speed.

Where can i set it that the whole object is printed with 100 mm/s

[Smithy 1,135]

Without more information it is hard to tell what's the problem. Please upload the 3mf project file from Cura.

[3D-Druck22 0]

UM3_4eck.3mf

[Smithy 1,135]

Are you sure this is the project? It seems it is just the STL, but maybe its me or my Cura installation.

Did you Cura -> File -> Save project ?

[3D-Druck22 0]

Yes that was the way how I did it.

[GregValiant 980]

As @Smithy says, it looks like an "export" rather than a project.

 

You are probably bumping up against the Minimum Layer Time.  The default is 10 seconds (to allow for cooling) and your cube is 20mm/side.  Discounting Accel and Jerk your calculated max speed is then 8mm/sec.  Cura's default minimum speed is 10mm/sec. and that is likely what you see in the gcode (600mm/minute).

 

Trying to calibrate Flow with one of these is contrary to common math (and common sense).

 

The volume required for any extrusion is Layer Height * Line Width * Length.  The E numbers that Cura generates are based on the filament diameter which gives the volume of filament for any given length of filament.  When Volume of filament = Volume of Extrusion you are at 100% flow.  Making changes to that ratio based on a wall measurement just doesn't make a lot of sense in the real world.

[3D-Druck22 0]

I tried it again to save it as a project.

UM3_4eck.3mf

[Smithy 1,135]

Now it works!

 

You have set 50mm/s for everything:

 

As @GregValiant already mentioned, I guess you run into the Minimum Layer Time limit, because your object is quite small, so when the printer decreases the speed to reach the min. layer time of 5secs.

 

 

So set it to 0 or 1 and it should work.

But again, don't expect that you get useable results with these settings, you will have a very poor bed adhesion and you print will look terrible when you ignore the min layer time to give the previous layer enough time to cool down.

[3D-Druck22 0]

So what would u advise me to do exactly? Which settings?

 

[GregValiant 980]

What are you really trying to do?  If you just want to print it fast then you need to make the model larger.  The print head has to speed up and slow down for each corner and the corners are sharp so essentially the print head has to come to a full stop at each corner.

If you scale the model to 750% in just the X and Y it will be 150 x 150 with 3mm walls.  To narrow the walls back to .4mm - set the Hole Horizontal Expansion to 2.6.

 

Now you have an object 150mm per side = 600mm periphery (actually 600 - 2 Wall Widths).  600mm / 100mm/sec = 6 seconds to make a lap around.

 

As @Smithy notes you will still need to adjust your minimum layer time to 5 seconds, all your printing speed settings to 100, and the printer should maintain your print speed mid-wall and your Accel and Jerk settings will come into play at the corners.  The higher the Acceleration settings then the quicker the starts and stops.  Your Ultimaker is much more capable than my Ender 3 Pro and can withstand higher Accel settings.  I don't know the Max XY accel on your printer.  Mine is 3000 and at that number the stops and starts are fairly violent so I don't set it that high.

 

I suppose you could scale the model, set Remove all Holes, set top bottom layers to 0, and print the model in Spiralize.  Again, it depends on what your are really trying to accomplish.

Edited October 11, 2021 by GregValiant