Can I use Octoprint via USB with MK3S  

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Active Member

This is the fan I ordered 


Pimoroni Fan SHIM for Raspberry Pi


anyone got experience of it?

Posted : 15/04/2020 3:16 am
Estimable Member

Its probably a little late now, but these should give you an idea of the basic components you'll need for a pi4:

Both are good kits, but this is not an Amazon ad.........just an easy visual reference so you can see what you will need to get up and going.  I don't recall if you mentioned your country, but its the US amazon listings. My personal opinion is fans with software, switches, and/or fancy headers are only good for adding headaches and problems.

This post was modified 4 months ago by nilok
Is your printer grinding? Bearings squeaking? Motors smoking?
Step 1) Wash your Steel Sheet
Step 2) Return to Step 1...
Posted : 15/04/2020 5:04 pm
Active Member

Thank Nilok, I live in Western Australia so amazon delivery/availability is different here.


hope those links help others decide.


im not sure whether this forum allows it, but a pinned notice about new raspberry pi’s vs old ones would be useful as I’ve found lots of post around with people building the old version requiring soldering and being out of their depth. Some then commenting that they didn’t realise a newer one was easier 


Posted : 17/04/2020 4:39 am
Estimable Member

I just posted the links so you could see the contents of each kit - not as an order source 😀  They illustrate good examples of cases, switches, power supplies, fans, heat sinks, etc.  Everything you'd need to get up and running - without extra fluff.

Is your printer grinding? Bearings squeaking? Motors smoking?
Step 1) Wash your Steel Sheet
Step 2) Return to Step 1...
Posted : 17/04/2020 6:25 am
Reputable Member

I have only heatsinks on the chips of my RPi4, no fan and it's quite enough. CPU load is always around 10%, very rarely a bit more. Temp is in the order 50-60 degrees (celsius). To be honest Pi3 is quite enough for octoprint (even Pi2 would do), but i chose Pi4 because of faster boot, faster handling of files, updates...everything is faster - i have official 7 inch LCD and OctoDash screen plugin. Fan is reccomended only in applications where CPU regularly reaches high percentages, but in octoprint it's just unnecesarry noisemaker.

Regarding RAM 1GB should be plenty, since never goes over 500MB, but since 2GB is only a bit more priced i'd say that 2GB is correct choice. 

Posted : 17/04/2020 10:15 am
Active Member
Posted by: @anders-3

As Mike says its basically plug and play:

1. Get a raspberry Pi. I would get a Pi4B, if you want to be future proof and run a webcam. 3B+ is also perfect. Get a USB webcam (I have the Logi C920) almost any model will do.

2. Burn OctoPi image to the pi sdcard. (there is also a small guide there)

3. Mount the sdcard on a computer, and edit the file octopi-wpa-supplicant.txt Use notepad++ on win, or sublime text on a mac

Look for the lines here:

## WPA/WPA2 secured
#  ssid="put SSID here"
#  psk="put password here"

and remove the 4 single # symbols from the last four lines. exchange put SSID here with your wifi name, and exchange put password here with your wifi password

5. (optional) If you want max resolution on the webcam also edit the file octopi.txt and find the line that starts with
remove the # and change it to camera_usb_options="-r 1920x1080 -f 30" this will set it to 1920x1080 30 fps

6. connect printer and webcam with usb to the pi. and insert the sdcard and power on. let it boot.

7. On a Mac you should bee able to access the octopi using bonjour, by visiting octopi.local in a browser

8. follow the install wizard and input the printer profile. I used this info from the Prusa GitHub site as reference:

    inverted: false
    speed: 7200
    inverted: false
    speed: 10200
    inverted: false
    speed: 10200
    inverted: false
    speed: 720
color: default
  count: 1
  nozzleDiameter: 0.4
  - - 0.0
    - 0.0
  sharedNozzle: false
heatedBed: true
id: _default
name: Prusa i3 MK3
model: Prusa i3 MK3
  custom_box: false
  formFactor: rectangular
  origin: lowerleft
  width: 250.0
  height: 210.0
  depth: 210.0

And also added the following in the octoprint UI because octoprint complained that the printer was different than my sliced files.

Under "Printed & Build volume"
Enable Custom bounding box
Set min to X=0, Y=-3, Z=0

- If you have a MMU2 mounted:
Under Printer profiles >  hotend and extruder:

Number of extruders = 5
Enable "Shared Nozzle"

9. Under settings > webcam. make sure "Enable webcam support" is checked and change "stream aspect ratio" to 16:9

10. (optional) Plugins:
OctoPi have a lot of plugins. I have the following enabled:
Dashboard - Gives you a very nice print overview on the frontpage.
Themify - Gives a nice theme to the UI
Display layer progress -u sed by dashboard
Action command
Enclosure plugin

11. In Prusa slicer you can add your octoprint server in your printer profile to make it possible to slice sand send it directly to the printer. Just edit the printer profile in prusaslicer and under General > Printer upload, you can add the octoprint address. The api key is fount in the octopi ui > settings >API

Thats about it.

Great info, i have PI thats been stuck in a draw for the past 2 years.  I might have to dig it out and use it for my printer.

Posted : 21/04/2020 11:28 pm
Active Member

I just waited 40 minutes to upload a gcode file to the sd card to an MKS over USB with Octoprint. I am just now noticing the api integration in the printer settings thanks to this thread! Does this method have the same speed issues as running with gcode streaming?

Posted : 21/06/2020 6:47 am
Reputable Member


"Does this method have the same speed issues as running with gcode streaming?" No

Posted : 21/06/2020 1:43 pm
Active Member

I just tried it out and it looks like PrusaSlicer just uploads the file to the local rpi and no the SD card of the printer. Everything I have read leads me to believe that if I run it from there I could run into a speed issue where the printer executes gcode faster than it can get it.

Posted : 21/06/2020 2:45 pm
Illustrious Member
Posted by: @zinefer

[...] Everything I have read leads me to believe that if I run it from there I could run into a speed issue where the printer executes gcode faster than it can get it.

That can be an issue in some specific circumstances. Adding unreliable plugins can also aggravate printing via Octoprint. For most of my printing over the last 2 years however, Octoprint printing via USB has been very stable.


My notes and disclaimers on 3D printing and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan...
Posted : 21/06/2020 7:08 pm
Active Member

Okay great, thanks for the information I will give it a try.

Posted : 21/06/2020 10:56 pm
Reputable Member

".... where the printer executes gcode faster than it can get it." From my limited knowledge of OctoPrint, thats is almost never a problem, whereas the reverse seems to be problem sometimes ie layer shifts associated with plugins.

Posted : 22/06/2020 11:59 am
Famed Member

I, too, have had sucess printing with octoprint via USB and WIFI.  I have 10 printers currently connected.  I also have Filament Manager installed with a cenrtal database of filament spools.  

Posted : 22/06/2020 3:14 pm
Noble Member

Thingiverse has printable cases for both the 3B and the 4B. They mount directly on the MK3S frame.

Space for a fan and a buck converter if you want. Happy user here.

Posted : 24/06/2020 10:45 pm
Famed Member

All of mine are connected through the RPI connector.  

Posted : 24/06/2020 11:36 pm
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