Prusa Mini and Octoprint  

RE: Prusa Mini and Octoprint

Has anyone taped or blocked their 5v pin on the USB? I'm getting some odd behavior at the start of a print when the hotend moves home for the primer line, the Y axis will move too far and make a terrible noise. I think it could have something to do with the 5v pin

More info here: https://community.octoprint.org/t/put-tape-on-the-5v-pin-why-and-how/13574

However, octoprint wont connect to the Mini if I cover the 5v pin. Has anyone else successfully done this? 

RE: Prusa Mini and Octoprint

Ok found out what was causing it to make that noise, had something on my table blocking it :/

Still wondering if anyone has taped their 5v pin on USB

RE: Prusa Mini and Octoprint

Posted by: @malcmcm

Ok found out what was causing it to make that noise, had something on my table blocking it :/

Still wondering if anyone has taped their 5v pin on USB

I haven't ever had a need or even thought you would ever need to, I use the micro-usb port.

RE: Prusa Mini and Octoprint

@robee

"Still wondering if anyone has taped their 5v pin on USB". Obviously it vary's depending on printer and Octoprint hardware but there is no downside in doing so. There is a thread on this subject in the Octoprint forum and in answer to your question, I do.

There are several good reasons for doing so. 

RE: Prusa Mini and Octoprint

@towlerg

What is your setup? Have you done it with a Mini? I cant connect to the printer after I tape my 5v pin. Not sure why.. I'm using a 3b+ pi. I've triple checked I'm taping the correct pin.

RE: Prusa Mini and Octoprint

@robee

"...or even thought you would ever need to" The reason is to prevent the 5v supply on the OctoPrint hardware powering the printer controller. Some printers leave the 5V pin on USB sockets (of whatever type) disconnected. Does your OctoPrint power supply have enough capacity to potentially drive both OctoPrint hardware and printer controller?

RE: Prusa Mini and Octoprint

@malcmcm

I have a Sovol SV-01 which uses a mini USB (not that that matters) and I also use a 3B+. All you need to D+, D- and Gnd. What version of OctoPrint are you using? There is a known fault with some versions of OctoPrint that cause problems with connection. I believe there is a work around plug-in and that the problem is fixed in the latest 1.4.2 version.

RE: Prusa Mini and Octoprint

Hmm, I'm using the latest version 1.4.2, what is the plug-in?

RE: Prusa Mini and Octoprint

@malcmcm

For ref the plugin was called PortLister but was intended to overcome auto port select issues with 1.3.12. I understand that the auto port detect logic was compleatly rewritten for 1.4.1. Suggest you post to OctoPrint forum with appropriate logs.

RE: Prusa Mini and Octoprint

I just setup octoprint and things seems to work (the ETA stuff, even with the prusa mini eta plugin, seems to be way off though).

I don't completely understand how it all works though. I've seen people write that if you don't put in the printer parameters correctly then a model may not print correctly (is this right?). Does that mean that octoprint doesn't just take the gcodes straight from prusaslicer and feed them to the mini. Is it somehow inserting its own stuff into the print job? I just figured it was a communication platform to send info back and forth.

I just want to be sure that anything I send from prusaslicer via octoprint will be the same as using a thumb drive in terms of what prints. 

RE: Prusa Mini and Octoprint

Posted by: @towlerg

@robee

"...or even thought you would ever need to" The reason is to prevent the 5v supply on the OctoPrint hardware powering the printer controller. Some printers leave the 5V pin on USB sockets (of whatever type) disconnected. Does your OctoPrint power supply have enough capacity to potentially drive both OctoPrint hardware and printer controller?

I doubt the circuit design on the Prusa printer controller would let that happen, this is the sort of thing I would only expect to be an issue on a controller built to a very low cost with minimal protection.

@cendrizzi Mostly those parameters are to enable it to warn you if you try to print something too big, I think, or if you are slicing Gcode on Octoprint itself. There are also settings for moving the axis which there is a forum thread with the correct values in, somewhere... 🙂

RE: Prusa Mini and Octoprint

Posted by: @cendrizzi

I just setup octoprint and things seems to work (the ETA stuff, even with the prusa mini eta plugin, seems to be way off though).

I'm not running a Mini, but I'm using the M73 ETA Override plugin with a Prusa Mk3 and Artillery Sidewinder and both produce print time estimates that are within 10% of both the PrusaSlicer estimates and actual print job completion. Not sure about the Prusa Mini ETA plugin as it doesn't show in the Octoprint list.

I don't completely understand how it all works though. I've seen people write that if you don't put in the printer parameters correctly then a model may not print correctly (is this right?).

There are options for print bounds checking that will complain if the information doesn't match where the print is done. There can be timing issues with OctoLapse.

Does that mean that octoprint doesn't just take the gcodes straight from prusaslicer and feed them to the mini. Is it somehow inserting its own stuff into the print job? I just figured it was a communication platform to send info back and forth.

Octoprint will inject gcode at various times, depending on how you've configured it. Startup and end gcode options are available, for example. The defaults are usually benign.

I just want to be sure that anything I send from prusaslicer via octoprint will be the same as using a thumb drive in terms of what prints. 

There shouldn't be any difference that affects the print. Very detailed prints (esp. curves) can be problematic using Octoprint, but most prints are just fine.

RE: Prusa Mini and Octoprint

@bobstro

Thank you for the response. That is very informative.

There shouldn't be any difference that affects the print. Very detailed prints (esp. curves) can be problematic using Octoprint, but most prints are just fine.

Why would printing through octoprint effect very detailed prints (in terms of printing)? If it's just using the gcodes from prusaslicer then shouldn't it be the same?

RE: Prusa Mini and Octoprint

Hmmm, I'm realizing you don't have access to the prusa tools for changing filaments and stuff. So you are supposed to do this through octoprint?

I also just switched to PETG, forgot to first layer calibrate, and canceled a print from octoprint that looks a little to close to the print surface. When I canceled it the head just stopped and left a really small dent in the print surface (I'm wondering if it went down further because it wasn't scratching). That's incredibly disappointing. I'm surprised canceling doesn't lift the head like it does when I cancel on the prusa.

RE: Prusa Mini and Octoprint

Posted by: @cendrizzi

Why would printing through octoprint effect very detailed prints (in terms of printing)? If it's just using the gcodes from prusaslicer then shouldn't it be the same?

There are 2 situations to be aware of:

• If Octoprint itself is slow -- usually due to faulty plugins -- print quality can degrade. If you notice unexpected stringing, layer shifts or other defects, be sure to run Octoprint in safe mode to see if the problem clears up.
• Very large numbers of very tiny moves (e.g. a large curved surface) can cause problems feeding over USB. I don't recall if the issue was serial transmission in general, the 115200 speed limit on the Mk3 or hardware limitations. It's not a pervasive problem, but again, one to be aware of if you encounter those specific circumstances.

One thing that is not readily apparent from using Octoprint is that it does a bit of "minification" on gcode being passed through to the printer. Gcode comments are stripped out and not sent over the USB port, thereby improving serial performance somewhat.

RE: Prusa Mini and Octoprint

Posted by: @cendrizzi

Hmmm, I'm realizing you don't have access to the prusa tools for changing filaments and stuff. So you are supposed to do this through octoprint?

You can, yes.

I also just switched to PETG, forgot to first layer calibrate, and canceled a print from octoprint that looks a little to close to the print surface. When I canceled it the head just stopped and left a really small dent in the print surface (I'm wondering if it went down further because it wasn't scratching). That's incredibly disappointing. I'm surprised canceling doesn't lift the head like it does when I cancel on the prusa.

You can customize the gcode Octoprint uses under the GCODE Scripts settings:

Octoprint is meant for a variety of printers, so I would NOT recommend using it to send gcode to your printer without first verifying it will function properly. I'd be particularly wary given some of the reports about the Mini acting oddly on shutdown gcode even straight out of PrusaSlicer. I don't own a Mini, so can't test anything specific.

RE: Prusa Mini and Octoprint

@bobstro

That makes a lot of sense. Didn't consider the speed limitations of using a serial connection. Especially when feeding real-time in the manner that it does. 

RE: Prusa Mini and Octoprint

@bobstro

I guess I need to take the time to learn gcode. I didn't know any of this stuff a month ago when I got the mini and lately, I've been trying to take a deeper dive, which included octoprint. I love what I see but I'm just a little leery now. 

RE: Prusa Mini and Octoprint

Posted by: @cendrizzi

[...] I guess I need to take the time to learn gcode. I didn't know any of this stuff a month ago when I got the mini and lately, I've been trying to take a deeper dive, which included octoprint. I love what I see but I'm just a little leery now. 

Ah, don't be leery! Octoprint is amazing, particularly when coupled with a Prusa printer. Like any tool, you want to learn the limitations, when to apply it and when to do something else.

In 2 1/2 years of printing, I've run into one case where an Octoprint plugin actually caused problems. The benefits have far outweighed any problems.

RE: Prusa Mini and Octoprint

@bobstro

Thanks for the encouragement.

I guess I just got leery because I just put a small dent in my printing surface. Luckily I bought an extra, so I now have a print surface to use until I figure out the best settings for octoprint. I actually don't think the head went down, I just think with my head being so low and not coming up the the normal filament that leaks out at the end pushed a dent into the surface because there wasn't enough room to expand outwards (the dent seems to have black petg stuck at the bottom that I can't get out but as said it's a very small dent). 

It's fun tinkering with this stuff regardless. I love with the Prusa that things work so well out of the box so the fun tinkering is completely optional.