I’m using a Printrbot Simple Metal, and printing a number of objects with MatterControl. With some objects, the printer will periodically stand still and do nothing for a second, as if it’s thinking about its next move. During this second, a bit of filament oozes out of the hot-end and forms a little ‘bump’ on the surface of the print.
These prints tend to go well for the parts where the print-head keeps moving, and I have the feeling it happens more for objects that are more complex, though I can’t be sure. Take, for example, the objects of this sword-shaped baby rattle: Baby Sword Rattle by Targ - Thingiverse. The ‘jewel’ object prints completely without pausing / bumps. The ‘pommel’ part has two or three pauses / bumps. But for the ‘blade’ part, the printer is pausing every 30 seconds or so, covering the blade with little bumps, that I’ll have to shave off after the print finishes.
Any advice?
Thanks in advance!
Aloha Mhelvens, I’m not familiar with Mattercontrol, but with Octoprint I was experiencing this same issue.
For me, it turned out to be the camera and the raspberry pi that ran my Octoprint could not handle the video and running the prints at the same time.
After i disabled the camera the printing went back to normal.
I also read in the forums that you can change the geometry detail on the slicer(for me simplify 3d) but never attempted that.
Good Luck finding the issue.
Mahalo, John
Hi John,
Thanks! So it actually is “thinking”? It does feel like a likely explanation. But in my case that almost certainly means the bottle-neck is the printrboard. It could hardly be my new laptop, nor the USB cable. But indeed, the blade on that model was quite complex. Perhaps it (and similarly complex models) could be simplified, so it requires fewer operations per second.
I’ll play around with that idea for a while, thanks. In the meantime, other tips would still be quite welcome.
Cheers!
How are you setup? i was thinking you had some kind of external device running a printer software. I.E. octoprint and a raspberry pi. Are you printbot>usb>laptop or printerbot>usb>raspberry pi type device?
If your using the first, try replacing the usb cable(the ones printrbot sends are crap) and switch the power supply to an atx. It will heat up faster.
Also what type of laptop are you using?
Mahalo, John
At the moment, It’s simply Printrbot → usb → laptop (though I’m working on a print-server with a Pi). I don’t think I’m actually still using the Printrbot supplied USB cable, but I’ll definitely swap cables and see if that works. I’m already using a (good quality) atx psu. My laptop is a Dell XPS 13-9350.
(PS: At the risk of going off topic, if you’re also using a Printrbot Simple Metal, did you find (or write?) a good tutorial for setting it up with a Raspberry Pi and Octoprint? I was able to connect to the printer, but I was unable to actually slice and print stuff.)
Hmm then its got to be a communications issue or somethings hanging on your computer.
Id double check the port speed on each end and maybe run process monitor while your printing and see if you see cpu spikes during printing, maybe also change the usb port to a 2.0 port instead of a 3.0 port. I’m just guessing here. 
Also take a look at page 9 of this doc to verify your usb serial port settings.
https://printrbot.com/wp-content/uploads/2015/01/PrintrbotsetupWindows7v2.docxRecovered.pdf
As for octoprint, i dont use it to slice. I just use it to send print jobs to due to the printer being in my basement.
I do the slicing with simplify3d then save the gcode to the octoprint.
Good luck and please post back if you find the fix.
Mahalo, John
Also try printing from the SD card, if this works then you know you need to be looking at the usb/computer and not the printrboard.
https://printrbot.zendesk.com/hc/en-us/articles/201730880
