E-step calibration: lessons learned

First, the bloody obvious: it would be much, much easier to do this without the enclosure in the way. Measuring 120mm of filament inside an A150 enclosure with calipers that have a depth gauge sticking out of the bottom . . . requires technique.

There is nothing special about the connection cable Snapmaker sent with the device (fortunately, since I’m not sure where I put it)—it’s a standard USB A <—> USB mini-B, or at least can be replaced by one. Although it’s been years since I last saw a new device that shipped with a mini-B port, it’s more physically robust than the more common micro-B, so not necessarily a bad choice.

Whoever wrote the Linux instructions for tethered connections with Luban forgot a couple of things. The Snapmaker2’s embedded USB-to-serial chip requires the ch341 driver ( CONFIG_USB_SERIAL_CH341=m )—this is very important to know if you build your own kernels. I also had to do a quick-and-dirty chmod on a node in /dev to get the two machines talking to each other (I assume this is what adding the user to the dialout group was supposed to avoid, but on the setup I was using, that accomplished absolutely nothing).

There is also no clear list that I can find of the libraries Luban needs. I needed to install libgconf and libnss (not otherwise present on the machine) in order to get it to run.

Last but not least, try to avoid doing this on a potato. My main computer is a desktop positioned nowhere near the Snapmaker, and the most recent laptop I have on hand is an Athlon64 x2 from 2008. I swear it took as long to start Luban up on that thing as it did to recompile the Linux kernel to get the required driver. Obviously, I did not try to slice any STLs on it. I imagine it would have worked its little silicon heart out and managed it eventually, but I saw no need to put it through that kind of stress. :wink:

You can lower the z-axis.

You can also make a mark on the calibration card/ruler to mark off the 120mm (why they didn’t print the ruler all the way to the end I can’t figure out)

-S

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Lowering the Z-axis was what I ended up doing. Finding something flexible to mark the length off on would have required getting up. :wink:

Rather than fiddling with drivers and all that, I think you’d have more fun spinning up octoprint either on a raspberry pi, or anything you can get to run on a single board computer, or in a container on your potato. The idea here being to run a print server, rather than a workstation. Plus, octoprint is just really cool. Adds a lot of functionality that Linux hackers will appreciate.

I have a Pi 3B that’s tentatively earmarked as some kind of server for the Snapmaker (I’m currently waiting on a Pi camera that will hopefully show up next week, because if I’m going to do that, I might as well monitor inside the enclosure too), but I would have ended up needing to know about the driver anyway, since I build my own Pi images rather than using Raspbian.

(What can I say? I’m a Gentoo user. We’re weird.)

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Hi.

It’s easier to load the pi image directly from octroprints webpage and configure the config file to get the network connection you need (fixed or WLAN).

I use a Pi4 with 4GB RAM. Works perfect and performant enough and a PiCAM in combination within my enclosure (A350).

Works great on a 3b as well for the record. The web interface is snappier on the 4 however. I have two instances running now for my Ender 3 and A350.

I have a long history of never doing anything computer-related the easy way. :sweat_smile:

However, since the Pi 3B has being lying on a shelf for over a year now, I figure I might as well get some good out of it rather than let it sit there until I get around to the project I originally bought it for.

Wait a minute, its supposed to be 120 mm? I did it 100 mm (i used some instructions on the forum someplace maybe i misread it)

Is there some way to compensate for the filament runout detection not working over octoprint or is that fixed?

There are different sets of instructions floating around, most likely. The one I used said to measure 120mm, extrude 100mm, and then measure to see if you have around 20mm left—makes sense to me, since if you measure 100mm and extrude 100mm, and it overextrudes, it might be difficult to figure out how much it overextruded by.

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@MooseJuice not as far as I know. Minor issue for me. Much preferred to have mobile access to printer controls. But honestly I have another 3dp so I will be in CNC and laser mode most times. But it’s really a non- issue because small jobs never run out, and if you can always upload from Luban over wifi anyways. Won’t even need to disconnect Octoprint.

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