Modify firmware according to my needs.
Hi there!
I do not post here very often since most of the info I ever needed is already published around here, but now I need some precise help.
I have the new Revo hotend installed on my Prusa i3 mk3s+ , works flawessly. To speed up the process even more, I'm one of those who have a large retraction at the end gcode just I case the next time I'm using the printer I want to change the nozzle even before turning it on. In order to compensate this retraction (In case I didn't change nozzle between prints), in the start gcode I also have a large extrusion (Same length)
And here's where the issue appears. You see, if I change the filament between prints (No matter if I change nozzles or not), the automatic "load filament" procedure leaves my filament just at the tip of the nozzle, and since all of my gcodes starts with that large extrusion... Well, you could imagine. Normally I do a retract manually after every filament change to avoid this issue, but sometimes if I'm in a rush I totally forget about that with disastrous consequences.
I was wondering if it is possible for a not-begginer but no-expert user to modify the firmware of my printer in order to change the behaviour of the "load filament" procedure to add a retraction after the confirmation for the correct color that the firmware already asks me for, for example. I did not investigate that much In my own on how to modify the firmware untill I get some sort of confirmation of that I will be able to do it.
I'm also open to hear some others propositions to solve my personal issue, maybe I can tackle this without touching the firmware at all. A prevent retraction at the start gcode "just in case" is not a solution because if the filament is already rectracted I get the filament completly out of the extruder. (Already tried it 😀 )
Thanks in advance.
Best Answer by FoxRun3D:
I haven't found a good reason yet to install the Revo I bought so I'm commenting from a position of ignorance.
Looks like E3D recommends compensating for that retraction by extending the prime line. https://e3d-online.zendesk.com/hc/en-us/articles/4406857421213-Start-and-End-G-code-for-faster-nozzle-changes. Wouldn't this work? Based on where the filament is inside the hotend, the line would simply be shorter or longer.
Feels more reasonable to me than messing around with the firmware, plus the gcode should work on machines with or without a Revo.
RE: Modify firmware according to my needs.
up!
RE:
I haven't found a good reason yet to install the Revo I bought so I'm commenting from a position of ignorance.
Looks like E3D recommends compensating for that retraction by extending the prime line. https://e3d-online.zendesk.com/hc/en-us/articles/4406857421213-Start-and-End-G-code-for-faster-nozzle-changes. Wouldn't this work? Based on where the filament is inside the hotend, the line would simply be shorter or longer.
Feels more reasonable to me than messing around with the firmware, plus the gcode should work on machines with or without a Revo.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
not-begginer but no-expert
Hmmm...
If you are in expert mode the startup can be modified in:
Printer Settings > Custom G-code > Start G-code
For G-code references look at:
https://help.prusa3d.com/en/article/prusa-specific-g-codes_112173
Maybe this is the next step towards becoming an expert...
Cheerio,
RE: Modify firmware according to my needs.
Sweet Jesus. I should have look for easier solutions, I just read that article and... You guys are right. Maybe I could have reached it in my own if only I was not directly searching for info about the printer firmware, I seriously thought that it was the only way to go. Why the @#!$ extrude on mid air while you can only make the purge line longer or thicker? Among so many other advantages vs tweaking the firmware directly, as you mention.
Woha, now I feel a little bit embarrased, I should not need a post here to realize this sort of things. Sorry about that, but thanks a lot for both of you for your time and help. I'm modifying the start g-code right now!
For me, this issue is solved 😉
RE: Modify firmware according to my needs.
Just a thought: You've modified the print sequence for every print to address those relatively infrequent times when you have swapped filament. I prefer to modify my filament swap procedure so it only needs to be addressed when actually swapping filament.
I personally prefer to leave filament in the hotend after a print to avoid a possible feed issue into the hotend after everything has cooled.
When swapping, I warm to nozzle to about 140C then pull the loaded filament. This gives me a cold pull every time I swap filament and pulls any crud out of the nozzle.
If I'm loading a cooler printing filament (e.g., PLA) after a hitter printing filament (e.g., PETG), I'll run some cleaning filament through and repeat the cold pull to reduce the odds of a partial clog.
This only adds to e when swapping filament and doesn't change anything for the 99% of prints that are done without a filament change.
It may be possible to change the gcode routine in firmware, but you'll need to do it for every release before upgrading.
Just my 2¢ worth.
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
I save a new printer profile for each change of this sort then it's just a matter of picking the one you need.
Cheerio,