Poor Print Quality MP Mini Delta Octoprint vs SD Card


What is the problem?
The print quality on a gcode printed from Octoprint is much worse than the exact same gcode printed from the SD card on my MP Mini Delta printer.

Left is SD card, right is OctoPrint.

What did you already try to solve it?
Disabled extensions, new install of Octoprint.

Additional information about your setup (OctoPrint version, OctoPi version, printer, firmware, octoprint.log, serial.log or output on terminal tab, ...)

MP Mini Delta, FW 43
OctoPrint 1.3.9, OctoPi 0.15.1



You can start OctoPrint in save mode to see if a plugin makes this trouble.
(Shutdown menu, last item)


I tried that, along with a new install of OctoPrint/OctoPi.


At these nasty blobs, is the print stucking for a moment?


Not that I can tell.


Then it looks like over extrusion.
Actually it sees those are the points where the extruder starts a new layer.
But when the gcode files (SD card(OctoPrint) are absolute the same, this should not happen.
I assume in the Control Tab, Flowrate is set to 100%

What slicer do you use?


Thanks for your help!

Yes, flowrate is 100%. I've tried Cura and S3D with the same effect.


What pi (hardware) are you using?

Share the gcode, I'll print it on my Mini Delta.


at which speed do you print?

When using octoprint i print with 35 mm when i want to go faster then i print with sd card

  1. Too little processor? (Raspberry Pi Zero only has one core)
  2. Serial-related problems? (Ferrite core and/or internal metallic shielding on serial cable). Turn on and then check the serial log.
  3. Losing Internet connection as combined with something that's trying to use the Internet.

Watch the print. If the printer is periodically pausing/stalling in places then this will result in what you're seeing.


I'm using a Raspberry Pi 3 B. It was previously used on a MP Select Mini without issue. Gcode is attached.MMD_3DBenchy.gcode (3.2 MB)

Printing with Repetier (and the same USB cable plus an extension) from my PC seems to work fine.

Speed doesn't seem to be a factor. I've tried everywhere from 30 to 100mm. I'm printing one at 20mm now to check.

I do not see any communication errors in the log. There may be some tiny pauses during the print (difficult to tell). It would certainly explain the blobs if this is the case. I considered interference or noise but there are no communications errors that I can see in the terminal (I could be wrong).

Is there a preferred baud rate? It detects and connects at 112500.

Keep the suggestions coming!


That's interesting, but you didn't say whether or not it either has ferrite cores or an internal metallic shield. Ferrite cores are pretty obvious. They're either there or they're not. Since you didn't just say that, I'll assume that it doesn't have any. As for internal metallic shielding, you can reasonably tell if you attempt to bend it, it will oppose you since the aluminum foil or the braided metal sheath is stiffer.


That seems to have fixed the problem! I didn't think that was it since it worked with the PC and I had replaced the cable previously with another MP cable to no effect. I had a better cable on hand and so far so good!



Well, it worked for less than a day. I have no idea what changed, but it's back to blobby prints even with the new cable. I'm going to send it back and get a different one to see if it makes any difference.


Check your power:


Great suggestion! I had considered a power issue, even going so far as to try another 2.5A Pi power supply (no help).

The problem is intermittent and it is working correctly this morning, but I'll do more testing this evening. The Throttled flag is currently 0x0. I'm not sure when I last rebooted though.

Meanwhile, I've tried:

Another MP Mini Delta
A different PI 3 B
Different USB cables
Different speeds
Fresh OctoPi install
Disconnecting Delta base cooling fan

I have a Pi 3 B+ on order, but I don't have high hopes for that solution.


It could be the power in your home. Is all this plugged into a UPS?


It's not. I'll give it a try.


I'm usually "the local electrician" at most places. You'd be surprised at how poor the building's internal wiring is. Turn on the air conditioner, the voltage goes down by ten volts. The refrigerator's condenser pump kicks on, the voltage goes down by five volts. Turn on the microwave oven, the voltage goes down by eight volts.