Printing with delta printer isn't working, very jittery.

CheetoJuice

Hi everyone,

I've been building a delta printer from scratch using the Mega/RAMPS 1.4 platform. I can control and home the printer without any issues using the manual controls in Repetier-Host—it moves accurately and smoothly across all three axes.

However, I run into a problem when I try to print something.

I upload an .stl file to Repetier-Host, slice it, and everything appears normal—the print path is displayed correctly, and the estimated print time looks reasonable. Since I haven't built the extruder yet, I select 'Dry Print' mode to simulate the movement. When I start the print, the printer homes itself and moves to the starting position, but then, depending on the slicer I used, it either stops completely or moves in small, jittery steps. Either way, it doesn’t move as it should.

The strangest part is that the UI shows the print progressing extremely fast, as if it’s completing a one-hour print in under a minute, even though the platform is barely moving.

I’m not sure if this is a firmware issue or if I’ve misconfigured something in Repetier-Host. Any help would be greatly appreciated!

Thanks in advance!

Repetier

Check if speed multiplier in host is 100% (default) if not it could explain the speed.

Also disable easy mode so you see log and check if there are communication errors. When buffer size is set too high you get man errors cauing start/stop often.

CheetoJuice

Thanks for the reply, I tried implementing these fixes but I've had no success.
One thing that I've noticed is that after I've sliced the model, the print preview, which shows me the path that the printer is going to take looks extremely jittery, random, and all over the place, nothing like what it should look like (I am trying to print a simple cube). This is the case when I try using all 3 of the integrated slicers within Repetier Host. If I try using PrusaSlicer outside of Repetier, it provides me with a path very systematic and normal looking. Maybe it is also important to note that I am controlling the printer by connecting my laptop directly to the Arduino, instead of using an sd card or whatnot. Thanks 

Repetier

We have no own slicers, we are just calling them with your selected configuration so especially with PrusaSlicer I expect the same result or the config contains the reason. For a cube each straight line must result in one single extrusion line. Check the cube if the triangulation is also as coarse as it can be. You can see this when you activate showing edges in host. If there are many subdivisions slicers will make one line per triangle and then it could be jittery.

CheetoJuice

Alright Thanks

CheetoJuice

Hi, I really appreciate the help, but i simply cant find the issue. I think the issue can be better identified if I share a video of what is happening with my printer. Take a look at the progress of the print, it is happening extremely fast and the software thinks the printer is printing at impossible speeds, whilst the nozzle itself is just vibrating. I am not receiving any errors in the log or anything. I hope google hasn't compressed the video too much. I have also included the firmware config file.

https://drive.google.com/drive/folders/116e3DC8XDkWFLuPFeSToE5rJxnK1ViLu?q=sharedwith:public%20parent:116e3DC8XDkWFLuPFeSToE5rJxnK1ViLu

Once again many thanks.

Repetier

Ok, looks good since homing is working. The fast speed probably means it is ignoring the moves. You should enable logging and see in communication log if you moved outside allowed area it might have disabled moves until homing. Just search for "error" in log. Object it self is small but quite for to the right. Typical candidate is a prime line at the start or something else in start code. Printer is clearly not executing the moves.

CheetoJuice

I figured it out. The issue was that I hadn't properly configured the print bed on repetier host in the printer settings>printer shape tab. Because of this, the slicing software would try print outside the print area. Many thanks.