RE: Unofficial Prusa Mini Wait Thread

To be fair all the pi needs to do is read a file like by line and broadcast it over uart at 115200. If that was all the pi did, it wouldn't be a problem even for the zero.

What makes things risky is the Web ui and the video streaming.

The pi 4 is also not the ideal solution since it has crazy power requirements and non standard USB c implementation. Combined with a non ideal power supply, and a camera it will respond to a low voltage warning by powering off the USB power rail, killing the print.

If you are to buy a device for octoprint look at the pi 3A. It is smaller cheaper powerful enough and with less finicky power supply requirements

RE: Unofficial Prusa Mini Wait Thread

@burtronix

yes, one line of gcode is an instruction "move this far in this direction" or "start squirting plastic" or "heat up to this temp" If you are printing a curve it's made up of lots of short line segments, the length of those segments which leads to the precision of the curve is adjustable in the slicer

What makes it harder to keep up at a higher precision is that if you are printing 1mm long segments of a curve, the printer gets to the point it needs the next instruction much faster than if it's printing a 5cm long line. So the pi needs to send instructions faster.

It's still a tiny amount of data to send compared to the theoretical limits of what usb can send or what the pi can process. It's just that with a single core pi zero, there's wifi, power management, and the whole octopi os and app that's competing for resources. It can bog it down for short periods even if it runs at 10% load most of the time. That would normally not be noticeable, but any pause in streaming the gcode makes your printer pause.

Does anyone know what kind of buffer there is in the printer for storing the gcode that's streamed to it? a decent buffer would hide any glitches in transmission.

RE: Unofficial Prusa Mini Wait Thread

Posted by: @burtronix

Posted by: @derek

@burtronix

No, it shouldn't matter.  Gcode is gcode and it's only going as fast as the printer is, which is only a handful of lines per second.  1Ghz should be plenty, assuming your resources aren't bogged down with other tasks.  The size of the gcode also doesn't matter, provided it's not bigger than the remaining RAM(512MB-OS usage with the Zero)

The Pi zero is 1Ghz single core and the Pi4 is 1.5Ghz quad core.  On top of other features, the Pi 4 is WAAAAY superior to the Zero in every way.  More expensive, yes, but the better value is in the Pi4 considering the Zero hasn't seen a CPU update since 2015.

Where you'll see the main difference in performance(between Zero and other Rpi versions is with uploading files into Octoprint and giving the printer commands.  The faster the CPU, the better.  On paper, the Rpi4 is 6x faster than the Pi zero but it's actually a lot more in reality due to CPU architecture and the fact your OS is tieing up a ton of resources on the Rpi zero.

I'm not an expert with these things but hope this helps.

Maybe I'm misunderstanding how gcode works. For instance, if you're printing a hollow cube with just 1 inner & 1 outer perimeter, a single layer would just need just 8 (2x4) move instructions. But if the shape were hexagonal, a layer would need 16 (2x8). Is it not true that more complex shapes need more lines of gcode? Don't more lines of code take longer to both upload & process ? 

Yes, the bigger the file is, the longer it takes to both upload and start the job.  Sorry, I thought you meant while the printer was printing if it would be too slow.  A better CPU will help with both uploading and starting the job but will affect starting the job more, because that entails processing the file and putting it into active memory.  After that it's on cruise control because it's only feeding commands one at a time.  So basically if you're using a Pi 3 or 4 for Octoprint over a Zero, you're paying for the convenience of not waiting several minutes for your job to start.  

RE: Unofficial Prusa Mini Wait Thread

@munkisquisher

Most printers have a config file in the firmware that defines the buffer size for usb.   You can edit it.  I believe it has to be a value that is a power of 2 (2, 4, 8, 16, 32, etc)

If your buffer is too small, the Pi Zero will definitely run into hangups and will intermittently stop.  This was the issue with the Raspberry Pi 1 many years ago and the fix was merely to increase your buffer to something higher like 32.  Same would apply with the Pi Zero.  The higher the buffer you set, the longer it takes to start the print(although it's only a few seconds in reality).  

Tbh, I've never had to mess with this on a Prusa, so I don't know how to edit it.  I haven't messed with a Pi Zero since I had a Printrbot.

RE: Unofficial Prusa Mini Wait Thread

@minos197

I disagree.  The PI 4 uploads the file faster and starts the print faster.  Every second is important in my busy life.  I have 4 printers on PI 3B and and 3 (soon to be 4) on PI 4.  I will convert them all to PI 4.  They are significantly faster at upload, connection to the printer, and starting the print.  I am not an expert, but it is noticeable. Connection with a PI 4 is near instant and the 3B can take 10-30 seconds.  That can add up over time.     

RE: Unofficial Prusa Mini Wait Thread

@ charles-h13

Is every printer owning his Raspberry Pi - on Octoprint instance running on one Raspberry Pi?

I was thinking about having 2 Octoprint instances running on one Raspberry Pi 4 (with 1GB RAM) - both having a USB-CAM for remote control. I read about in the OctoPrint forum, that this should in principle be possible.

Best regards,
Clemens Mödlin

RE: Unofficial Prusa Mini Wait Thread

Posted by: @littleneutrino

@aualow

😯aww, another one after mine that has shipped 😛 it'll happen eventually lol.

I'm in the same boat as you, with orders after mine already shipping.  I keep having to remind myself that patience is a virtue, lol.

RE: Unofficial Prusa Mini Wait Thread

@clemens-m

Each one has its own pi

RE: Unofficial Prusa Mini Wait Thread

Nice that that Mini's are rolling out again. Eager to hear, what changes where made to the printer... As there is no official announcement from Prusa Research...

RE: Unofficial Prusa Mini Wait Thread

Anyone have trouble flashing the firmware on initial boot?  Mine just resets...

Edit: Never mind.  Pushing the knob is NOT intuitive! 🤣 🤣 

RE: Unofficial Prusa Mini Wait Thread

I know that the Prusa team are all very busy, but what would be very cool.....

Someone from Prusa to update and complete the wait thread google document with the verified delivered (received) minis.

I understand that the document is an online and community managed collaborative document. However, I believe that many people would not bother to update the received status.

Just a thought/hope/wish

RE: Unofficial Prusa Mini Wait Thread

10/13 order - Shipping notice received today. Spreadsheet updated. Woo Hoo!

RE: Unofficial Prusa Mini Wait Thread

Posted by: @charles-h13

I will post more on speed tonight.  I think it is actually faster.  I am going to print the same item with the same filament and confirm speed tonight.  

Hey Charles, how did you get on with the speed comparison between your mk3/s and the Mini?

Texy

RE: Unofficial Prusa Mini Wait Thread

@texy

Time for away from me.  I need to open a new spook of filament and pick a test print, I will do it tonight.  

RE: Unofficial Prusa Mini Wait Thread

Posted by: @brian_charlton

I know that the Prusa team are all very busy, but what would be very cool.....

Someone from Prusa to update and complete the wait thread google document with the verified delivered (received) minis.

I understand that the document is an online and community managed collaborative document. However, I believe that many people would not bother to update the received status.

Just a thought/hope/wish

I don't think they can do that, it's their internal data, plus it's customer data. People share it on voluntary basis, giving consent by filling those lines. But company cannot do that for their customers. GDPR and privacy and stuff.

RE: Unofficial Prusa Mini Wait Thread

Prusa are actually not happy about the unofficial spreadsheet as customers are complaining that there Mini didn't ship before others below them in the list. So, no, there will not be contributing to it. However at least the shipping table is really now a table and gives more info than it did previously.

Texy

RE: Unofficial Prusa Mini Wait Thread

@charles-h13

If you are opening new Spooks of  filament, this might be an ideal model

Thingiverse

https://www.thingiverse.com/thing:4421

🤣

Joan

RE: Unofficial Prusa Mini Wait Thread

Posted by: @texy

Prusa are actually not happy about the unofficial spreadsheet as customers are complaining that there Mini didn't ship before others below them in the list. So, no, there will not be contributing to it. However at least the shipping table is really now a table and gives more info than it did previously.

Texy

They stated few times that numbers are assigned to orders, but it's not an indicator of shipment queue. Their ERP decides on that based on parameters we may not know (components, plastic parts inventory, destination, arrangement with couriers etc.). It's rather inconsiderate if people are bothering representatives based on this spreadsheet,we will never have full picture.

RE: Unofficial Prusa Mini Wait Thread

@texy

We have to live with the wait so I guess they will have to love with the spreadsheet.  

RE: Unofficial Prusa Mini Wait Thread

@joantabb

I might try that one.