And by the way, i would be happy if you prove me wrong. 1. It means ive learned something new and (one reason for such communitys) 2. It means that preston will maybe have less work to do later
@Sven_Eric_Nielsen this is damned slow, but this is worse than others that I heard of. https://youtu.be/JW6yJvLF7Jk
https://vimeo.com/101339613 @Sven_Eric_Nielsen
I tried to find evidence of Polar3D being pi powered but I kept missing that bit of evidence.
The people keep making pi controlled printers slow, but that may be a bit much in their OS install and a poor choice of core usage (default is 1 core heavy on Linux for some stupid reason).
@NathanielStenzel
Well, this is the printer that I already know. So where are all the others?
If you tried to follow the story of this printer you’ll see that it starts where it ends, in 2014.
Heh. Me having a reputation. I have illusion of a decent one. I just recall some stuff.
There were only a few out of hundreds. It exists but is rare and few have them running fast. Lack of temp control loops off the pi may be another reason for slow prints.
@NathanielStenzel
Sorry, was not meant to be an offense.
But seriously, I’ve never seen a project that was able to show a working printer with a reasonable concept to be competitive. Even not against an outdated ramps system.
And if there is something I would think that it should be much more famous than it’s actually is. But only due to the fact that there is nothing famous I think there is nothing that makes sense. Most of these projects never really passed the first prototype. They all died because they found the same well known issues with a non-realtime system.
On a cnc it’s not so critical. On a closed loop system it’s maybe also possible. But on 3D printers, as they are today (cheap, fast, reliable)…i don’t know…
@Preston_Bannister the core in rp3 wasn’t designed in US. I’m well aware of the encryption wars though.
@Sven_Eric_Nielsen there are so many printers out there. It is hard to be better than mediocre as a 3D printer. It is hard to be more than mediocre as a computer programmer. Sadly, I am a computer programmer. At least that is my prefered work. Just call me and the pi based printerx chump change. I will not disagree with either. I mentioned what I figured would overcome the pi based printer speed issues. Hopefully people will use those tips if they try. I guess it would have bypassed the majority of the discussion if I said that there were a few pi based computers, but they had speed issues and the idea in general is considered less than practical by many. (shrugs)
On a side note, even in octopi setups, the core usage of the raspberry pi is pathetic. I have pulled up the core usage info in top via ssh before. Seriously, they need to chexk into core usage adjuztments and see if it can be improved. At least slice on a different core (perhaps 2) and send gcode on core 3. I will have to try core usage adjustment myself to see how it works. It seems a pi only uses 1/3 of its processing power when it is drowning in workload for OctoPrint.
Well, OK, to sum up (maybe)…
The only examples we know of (and that I could find, as well) for a Raspberry Pi directly controlling a 3D printer are old and slow.
In part this is not surprising, as there is not really a good add-on board appropriate to the task. That means you have to make suboptimal choices when driving the printer, thus slow printing.
(We could have a sub-discussion about how hardware and software folk view the problem in different ways, and that causes a measure of confusion. Takes some effort to converge.)
Was watching Trinamic videos yesterday. They sure have some very nice “smart” stepper-drivers. (Off-topic question, does g2core know how to fully use the stepper-drivers I bought, or am I going have to teach it to do so? Fine with me either way.)
Pretty sure a decent hardware guy could put together a “hat” for the Pi, with Trinamic drivers, that would allow the Pi to serve as a superbe controller for a 3D printer. But that board does not exist.
Pretty sure a decent software guy (perhaps me) could write the software for the Pi to match. (Use the Pi 3. Use CPU affinity to lock the printer-controller task to a single CPU. Use interrupt affinity to steer other processing to other CPUs. Do not need the full general case of real-time Linux, as this is a fairly simple problem. Use smart stepper-drivers.)
But you do kind of need both kind of folk - and so far, for whatever reason, that has not happened.
Also, to be clear, I am not taking that path in my current iteration. For this iteration I want to get g2core working with least trouble, so an Arduino Due, RADDS, and Trinamic drivers are the first choice.
@Preston_Bannister
Indeed this happened. Just Google for beagle bone and cramps or replicape.
But the point is that even this is not a pure pi like thing. Even these developers noticed that it doesn’t make sense to use a pure pi (when you want a competitor to existing things).
So they used a pi like system with additional co processors for the realtime tasks. (The beagle bone comes with 2 PRUs)
As mentioned several times by me and a few other other people here :
Do the research about the state of the art before making assumptions 
And by the way, it not only a question about the stepper drivers.
We are also talking about many other things that needs to be calculated and controlled in real time and in sync with the actual status of the printer.
I do have a few 24v g2 boards. and Polar3D used the standard Printrboard. Bill uses the pi to communicate to their cloud as far as I know since he’s helping me w the Printrbelt and it uses this configuration.
Btw the Printrboard is 24v ready, I just don’t publicize it.
@Brook_Drumm Given there are nominally 400K folk in this group, you may have just slipped up. 
Ha! I have no secrets. I am planning to go 24v on the upcoming Plus Pro… maybe even the Printrbelt.
Brook