Linear Advance, is it coming back?  

Re: Linear Advance, is it coming back?

Oh I will feed you baby birds. 🙂 From the 3.1.2 RC1 firmware thread:

3.1.2 RC1 won't compile with LIN_ADVANCE defined, I am working on getting a pull request in to fix (Edit: https://github.com/prusa3d/Prusa-Firmware/pull/503 ). Looks like they renamed a function and skimmed over changing it in an linear advance defined section:

Old code in ConfigurationStore.cpp, calculate_volumetric_multipliers() no longer exists because it was renamed:
#ifdef LIN_ADVANCE
if (level >= 10) {
EEPROM_READ_VAR(i, extruder_advance_k);
EEPROM_READ_VAR(i, advance_ed_ratio);
}
calculate_volumetric_multipliers();
#endif //LIN_ADVANCE

My change to match up with what they did elsewhere:
#ifdef LIN_ADVANCE
if (level >= 10) {
EEPROM_READ_VAR(i, extruder_advance_k);
EEPROM_READ_VAR(i, advance_ed_ratio);
}
calculate_extruder_multipliers();
#endif //LIN_ADVANCE

After that change it compiles with no issue, and I have it printing a calibration cube now without problems. Make sure you do self test again, as it does have a "calibrating home" step where it bumps X and Y limits several times to determine this. Please find my unofficial LA enabled firmware below:

MK3-3.1.2-RC1-LA-ENABLED.zip

Thanks for debugging. I just ran into this myself.

Re: Linear Advance, is it coming back?

Hi... thanks for posting this...

I would like to ask some noob questions:

could not find the "experimental" menu...

on the josef prusa blog he talk about a 0.2mm LA Experimental slic3r profile that i don't have on my Slic3r Prusa edition 1.38.6-prusa3d-win64

can you kindly share some speed values for PLA, on Slic3r / print settings / speed?

Thanks in advance

Gustavo

Re: Linear Advance, is it coming back?

Hi... thanks for posting this...

I would like to ask some noob questions:

could not find the "experimental" menu...

on the josef prusa blog he talk about a 0.2mm LA Experimental slic3r profile that i don't have on my Slic3r Prusa edition 1.38.6-prusa3d-win64

can you kindly share some speed values for PLA, on Slic3r / print settings / speed?

Thanks in advance

Gustavo

You shouldn't need to make adjustments in the Slic3r profiles, they still send the appropriate command to set Linear Advance. You do need to have it turned on in the firmware (this customized version does). As far as the "Experimental" menu in the printer settings, that is only enabled if you compile the firmware with that flagged on and is not required to use Linear Advance.

Re: Linear Advance, is it coming back?

thanks!!!

i have found the 0.2mm LA experimental settings... will try it soon as i can...
sorry for the trouble
😀

Re: Linear Advance, is it coming back?

So to clarify, Linear advance doesn't play nice with OctoPrint only works on SD prints. So if one wants to try linear advance and still be able to use Octoprint, without using linear advance, one can slice in S3D using their provided profiles, then to print using linear advance can slice in Slic3r? Or does linear advance not play nicely with OctoPrint period?

Thanks

Re: Linear Advance, is it coming back?

So to clarify, Linear advance doesn't play nice with OctoPrint only works on SD prints. So if one wants to try linear advance and still be able to use Octoprint, without using linear advance, one can slice in S3D using their provided profiles, then to print using linear advance can slice in Slic3r? Or does linear advance not play nicely with OctoPrint period?

Thanks

Linear advance is a firmware setting. If you download the firmware and edit Configuration_adv.h, there's a line that defines if LIN_ADVANCE. If it's defined, all the LIN_ADVANCE functionality throughout the firmware activates, if it's not defined it skips over them. If you look in your Slic3r filament gcode settings, you'll see some M900 K commands that set Linear Advance values; however, it's ultimately that LIN_ADVANCE flag that determines if the printer does anything with it.

That said, I don't know if you can have LIN_ADVANCE defined and simply set it to "off" on some prints by omitting the M900 K gcode (I am betting not). The problem was the LIN_ADVANCE calculations were taking up too much CPU time and causing serial communication to Octoprint to lag and fail out. This lag doesn't seem to affect the sdcard prints, and I just pulled a 19 hour print off the bed to that effect; however, just having LIN_ADVANCE defined may be enough to lag out serial communication to Octoprint.

I hear it's possible to get Octoprint to store prints onto the printer's sdcard and kick off prints from there, but you suffer a reduction in functionality (probably no real time status updates, maybe someone can chime in on this). Personally, I think Linear Advance is enough of a quality boost that I would go without Octoprint for it.

Hopefully that helps. 🙂

Re: Linear Advance, is it coming back?

So to clarify, Linear advance doesn't play nice with OctoPrint only works on SD prints. So if one wants to try linear advance and still be able to use Octoprint, without using linear advance, one can slice in S3D using their provided profiles, then to print using linear advance can slice in Slic3r? Or does linear advance not play nicely with OctoPrint period?

Thanks

Linear advance is a firmware setting. If you download the firmware and edit Configuration_adv.h, there's a line that defines if LIN_ADVANCE. If it's defined, all the LIN_ADVANCE functionality throughout the firmware activates, if it's not defined it skips over them. If you look in your Slic3r filament gcode settings, you'll see some M900 K commands that set Linear Advance values; however, it's ultimately that LIN_ADVANCE flag that determines if the printer does anything with it.

That said, I don't know if you can have LIN_ADVANCE defined and simply set it to "off" on some prints by omitting the M900 K gcode (I am betting not). The problem was the LIN_ADVANCE calculations were taking up too much CPU time and causing serial communication to Octoprint to lag and fail out. This lag doesn't seem to affect the sdcard prints, and I just pulled a 19 hour print off the bed to that effect; however, just having LIN_ADVANCE defined may be enough to lag out serial communication to Octoprint.

I hear it's possible to get Octoprint to store prints onto the printer's sdcard and kick off prints from there, but you suffer a reduction in functionality (probably no real time status updates, maybe someone can chime in on this). Personally, I think Linear Advance is enough of a quality boost that I would go without Octoprint for it.

Hopefully that helps. 🙂

The only reason I like OctoPrint is that it saved my butt the other day. I typically queue prints in the morning and monitor them from work then when I get home. The other day a small part separated from the bed and the printer was spewing filament where the part was and I was able to kill the job from my desk. Otherwise I'd happily just print from the SD Card. I'm a bit curious about linear advance though. Maybe I'll try flashing this weekend for fun.

Thanks for the answer.

Re: Linear Advance, is it coming back?

The only reason I like OctoPrint is that it saved my butt the other day. I typically queue prints in the morning and monitor them from work then when I get home. The other day a small part separated from the bed and the printer was spewing filament where the part was and I was able to kill the job from my desk. Otherwise I'd happily just print from the SD Card. I'm a bit curious about linear advance though. Maybe I'll try flashing this weekend for fun.

Thanks for the answer.

It really depends on what you print. If you are printing a lot of organic models you probably won't notice much. If you are printing things like parts with hard edges or need a lot of precision, it's pretty great.

Example:

Re: Linear Advance, is it coming back?

Just a quick test print to ensure Linear Advance was reliable with sdcard. 48 hours, ish. 🙂

Lots of sanding and painting in my future. 🙁

Re: Linear Advance, is it coming back?

Hello,

3.1.2 was released today and is on the Prusa Downloads page ( https://www.prusa3d.com/drivers/ ). I haven't made it home from work yet to test it, but I was able to rebase and recompile this via remote connection. Here's 3.1.2 with LA enabled for sdcard bros only. 🙂

Re: Linear Advance, is it coming back?

Welp, with LA officially coming back soon it's probably time to let this thread die off. Can't resist one more release though to get us by until then. 🙂

This has all the latest commits since the 3.1.2 release plus LA enabled. I haven't had a chance to test it, but we've had pretty good luck turning it on so far. Bonus, this also has stahlfabrik's z-offset fix applied for more consistent first layer height. Please report your results here: https://shop.prusa3d.com/forum/original-prusa-i3-mk3-f30/first-layer-issues-look-here--t14681.html

Re: Linear Advance, is it coming back?

This has all the latest commits since the 3.1.2 release plus LA enabled. I haven't had a chance to test it, but we've had pretty good luck turning it on so far. Bonus, this also has stahlfabrik's z-offset fix applied for more consistent first layer height. Please report your results here: https://shop.prusa3d.com/forum/original-prusa-i3-mk3-f30/first-layer-issues-look-here--t14681.html

LA included is key (ok still running b122 because it has LA and runs just fine tbh), but very curious to try with stahlfabrik's fix. And the rest of 3 months of firmware updates too. It's not a production environment for another few weeks, so can roll back if I have to 🙂

Thanks B.

Re: Linear Advance, is it coming back?

Awesome, thanks for doing this. I'm an SD card only user so i'm pretty excited to try this out. .

Now, what about the temp correction on the PINDA probe fix, has that been included in anything official yet? Was there a conclusion to that I missed?

Re: Linear Advance, is it coming back?

Having problems since 3.1.0 firmware update, with or without OctoPrint...
Seems random, the same gcode is stopping at different times.
I tried printing with SD as a workaround but I also get into problems, the printer prompting for "Waiting for user input" and waiting with the hotend sitting on and running the current print.

Art least with OctoPrint I can "Fake Acknowledgement" remotely, if not too late.

Having to babysit the prints is not always possible, I can't run long prints at all unless I don't sleep for as long as it prints.

Any hopes?