Print time estimates wildly inaccurate


I've always noticed the print times in Octoprint seem to be about half-right. Meaning, it usually takes about twice as long as estimated.

It's not my slow pi. It might be my slow printer. But I can tell the printer is staying fed all the time since the speed doesn't drop between lines.

I shrug and get on with life. When the time turns out to be more accurate than usual, it's like I got a little part of my day back.


I'm also quite curious about the estimated print time, because for my first use it is double what the slicer says.

New to OctoPrint, Raspberry Pi etc. and still a newbie at 3D printing.

Have printed a dozen things sliced with Cura3D on my Creality Ender 3D, the print time would never seem to be off, maybe a couple minutes for a multi-hour but still simple item (on finer resolution and average print speed).

Just created an updated version of an item, which takes a good 4 - 5 hours ...

5 hour print

Uploaded the gcode via OctoPrint to the Raspberry Pi 3B and let it start printing.
An hour into the print, I check in via the web interface: 9 hours remaining?
So essentially,

10 hour print

Quite puzzling.

I'm currently also not seeing any progress indication on the progress bar on the printer. It is printing the base, the slowest part of the item, but still ...

Guess I'll know in a few hours and update.


Since v1.3.9 of OctoPrint, foosel's opened up some things in the API so that others can write plugins which directly address this. Visit the plugin page, hit the more link at the bottom and see what's available.


Actual print time was ~ 5 hrs 17 mins.


I suggest to watch

The challenges of live print time estimation (which you had going there, no analysis result available at start of print) are explained there starting at the 44min mark.


Side question, where did you get that set? Can you share?




Is octoprint setup to take a timelapse? This could slow the print time somewhat if the print stops to take a photo every layer.


Look for that magnifying glass icon in the upper-right corner of this page and enter the word timelapse. Many topics exist for this question.