Better prime line (plea to Prusa)  

Re: Better prime line (plea to Prusa)

I use a line of kypton tape on prime area, how's that easy?

Re: Better prime line (plea to Prusa)

[...] So you are printing the purge line in a different position each time, based on the object you are prinitng?I looked into randomizing the start location, but while you can approximate it, I'm not sure it helps with the issue of wear on the PEI bed. I've settled for giving the prime area a wipe with my fingers before a print and that's doing the trick. The prime line and the skirt serve very similar functions, so you could just eliminate the prime line and do an extra circuit with a skirt to ensure material is flowing.

You're welcome to take a look at my start g-code. The purge line routine is in lines 28-38. Nothing magical, but I did add a line to add a bit of a fat "blort" of filament to knock off any ooze at the start, and a wipe action at the end to try to eliminate any stringing. The OP's suggestion in this thread could easily be incorporated into those lines if you like. Let me know if you have any questions.

Re: Better prime line (plea to Prusa)

Please read that entire thread again... carefully. 😉

I have clearly missed something, but I am not even sure which post you want me to go back to read.

Going back through your posts in this thread, you've only referred/linked to one thread... twice.
That's the only thread I've been referring to--the one you posted:
https://shop.prusa3d.com/forum/general-discussion-announcements-and-releases-f61/better-prime-line-plea-to-prusa--t24540.html

I admit it.. i am a little lost now.. Can we start again as I just think we have the wrong opinion of each other.

I merely responded to this thread and highlighted your solution to this problem (Randomizing the purge) as I was trying to help.. I thought you would appreciate that?

So can I simply ask.. Are you still using this workaround? Do you have any problems with it?

Jon

Re: Better prime line (plea to Prusa)

I have clearly missed something, but I am not even sure which post you want me to go back to read.

Going back through your posts in this thread, you've only referred/linked to one thread... twice.
That's the only thread I've been referring to--the one you posted:
https://shop.prusa3d.com/forum/general-discussion-announcements-and-releases-f61/better-prime-line-plea-to-prusa--t24540.html

I admit it.. i am a little lost now.. Can we start again as I just think we have the wrong opinion of each other.

I merely responded to this thread and highlighted your solution to this problem (Randomizing the purge) as I was trying to help.. I thought you would appreciate that?

So can I simply ask.. Are you still using this workaround? Do you have any problems with it?

Jon

It seems like you are trying to troll Rufus. If not, then you should know that you have him confused with Retireejay who is the person who is doing the random purge line. Rufus simply pointed out that if you are randomizing it, you need some method to make sure that it doesn't interfere with your print.

Re: Better prime line (plea to Prusa)

It seems like you are trying to troll Rufus. If not, then you should know that you have him confused with Retireejay who is the person who is doing the random purge line. Rufus simply pointed out that if you are randomizing it, you need some method to make sure that it doesn't interfere with your print.

Oopss.. How much of a nob do I feel? I am certainly not trying to troll anyone.. As you correctly summized, I absolutely confused Rufus with Retireejay.. Not sure how that happened, but it seems that a few pages back when he replied to me I assumed (incorrectly) that he was........ I doesn't matter.. I don't want to appear like I am making excuses.. I am wrong and now understand why Rufus reacted as such.

Sorry all.. Sorry Refus.. Completely my fault....

Jon

Re: Better prime line (plea to Prusa)

The best solution for a random purge line would need to reside in the slicer. Have an option for which axis to place it, x or y, how long to make the purge line, and how far away from the print/skirt. Biggest issue then is getting the slicer developers to impliment it.

Re: Better prime line (plea to Prusa)

The prime line and the skirt serve very similar functions, so you could just eliminate the prime line and do an extra circuit with a skirt to ensure material is flowing.

Unless, of course, you've eliminated those pesky skirt lines, which don't seem to serve much practical purpose, anyway... 😆

Bobstro suggests a pretty good alternative, like most that have been proffered in these threads. (Though I'm not sure if I could bring myself to smudge up the build plate I had just cleaned... "Clean... but not TOO clean!" 😀 Tiago's suggestion of using Kapton tape sounded reasonable, too.)

Currently, I'm only printing in PLA, and not that much at the moment, as I continue to "endeavor to persevere" figuring out why I can't get a consistent first layer*... (Ah, the elusive consistent first layer.... !) ...so there isn't currently much wear on the PEI.

Eventually, (probably sooner than later) I'll have to acquire & begin printing some PETG (or some alternative suitable for functional parts--that NGEN stuff Bobstro mentioned? Still wish I could find what it is/what's in it other than, "It's PLASTIC, Dummy!") 😉 Until then, I'm filing away all these little hints & tips... 😉

*Making my way through Joan's last list of possibilities...

Re: Better prime line (plea to Prusa)

[...] Unless, of course, you've eliminated those pesky skirt lines, which don't seem to serve much practical purpose, anyway... 😆 I have to admit I like watching both. The prime line gives a good sense of whether everything is flowing properly, the skirt outlines where the print will go.

Bobstro suggests a pretty good alternative, like most that have been proffered in these threads. (Though I'm not sure if I could bring myself to smudge up the build plate I had just cleaned... "Clean... but not TOO clean!" 😀I've noticed that my PEI sheet has definitely "seasoned" over time. Prime lines that used to be difficult to remove lift off easily. I seem to need less cleaning with alcohol now too. It reminds me of my grandmother's iron skillet she used for fried chicken. Woe be unto anybody that cleaned it!

Currently, I'm only printing in PLA, and not that much at the moment, as I continue to "endeavor to persevere" figuring out why I can't get a consistent first layer*... (Ah, the elusive consistent first layer.... !) ...so there isn't currently much wear on the PEI.Keep with it. Once you've got it, it really helps with gauging whether a print will succeed. I like to watch the 1st layer, then have a pretty good idea of whether things will work for the rest.

Eventually, (probably sooner than later) I'll have to acquire & begin printing some PETG (or some alternative suitable for functional parts--that NGEN stuff Bobstro mentioned? Still wish I could find what it is/what's in it other than, "It's PLASTIC, Dummy!") 😉 I can't say that PETG is any more meaningful than COPA to me. PETG works well, but seems to be a bit "soft" in appearance. The NGEN prints like PLA with very crisp features, but is tougher and more temp tolerant. NGEN is expensive compared to PETG and PLA, but is one of the cheaper co-polyesters. You might try looking through the Q&A for different materials on the MatterHackers pages. Unfortunately, you have to look at each variation (e.g. different questions on NGEN black versus red pages for the same materials) but there are nuggets of good info there. One described mentioned "... PETG and Ngen are very similar materials. They are both PET copolymers, and as such, they are hygroscopic."

Until then, I'm filing away all these little hints & tips... 😉 Definitely the way to do it. I was keeping everything in an online notebook, then just transferred it to my projects pages. This hobby is full of little tips and tricks that never seem to get collected in any one place.

Re: Better prime line (plea to Prusa)

Currently, I'm only printing in PLA, and not that much at the moment, as I continue to "endeavor to persevere" figuring out why I can't get a consistent first layer*... (Ah, the elusive consistent first layer.... !) ...so there isn't currently much wear on the PEI.Keep with it. Once you've got it, it really helps with gauging whether a print will succeed.

Well... that's the thing; our prints are successful. The first layer has that "spaghetti" look on one side, and small waves on the other, but once the successive layers get to covering it up, all we're left with is the "washboard" effect on the bottom where the "spaghetti" was/is. The only time it's a real issue is when the bottom surface finish is important, and that's not terribly often...

Until then, I'm filing away all these little hints & tips... 😉 Definitely the way to do it. I was keeping everything in an online notebook, then just transferred it to my projects pages. This hobby is full of little tips and tricks that never seem to get collected in any one place.

We find OneNote very useful for that kind of thing.

Re: Better prime line (plea to Prusa)

[...] We find OneNote very useful for that kind of thing.

I've been a big fan of EverNote. Now I'm reading that they may be in trouble. I've got access to OneNote, but I really want to keep my personal and work stuff separate.

Re: Better prime line (plea to Prusa)

Well... that's the thing; our prints are successful. The first layer has that "spaghetti" look on one side, and small waves on the other, but once the successive layers get to covering it up, all we're left with is the "washboard" effect on the bottom where the "spaghetti" was/is. The only time it's a real issue is when the bottom surface finish is important, and that's not terribly often

From my very inexperienced opinion I think your first layer IS important as it is telling you your Z height is not correct. This would set the tone for the whole construction and maybe your prints are not as strong or smooth as they could be.

See https://shop.prusa3d.com/forum/assembly-and-first-prints-troubleshooting-f62/first-print-tips-t24520.html
This also links to a long discussion on getting the live z just right.

Re: Better prime line (plea to Prusa)

From my very inexperienced opinion I think your first layer IS important as it is telling you your Z height is not correct. This would set the tone for the whole construction and maybe your prints are not as strong or smooth as they could be.

I appreciate what you're saying, and don't disagree, but my ordeals with trying to get a consistent first layer are (seemingly) becoming somewhat legendary on this forum. 🙄

I continue to endeavor to persevere... 😉

Re: Better prime line (plea to Prusa)

I've always put a line of blue tape along the edge. Keeps the whole area clean and makes it super easy to remove PETG priming lines. I've also extended my prime line about 50mm.

I did this too until i ran out of thin blue tape. I didnt think it would be an issue this long and didnt bother buying any more tape because i assumed id have a PC sheet by now, lol joke is on me i guess.

The purge line area though by far will be the first part of my PEI sticker that gets damaged enough to warrant replacement.

Re: Better prime line (plea to Prusa)

The solution have found works best for me is to use a piece of Kapton tape on the prime line area, it’s lasted for over 50 prints with PETG so far.

Video showing Kapton Tape to protect prime line area

Re: Better prime line (plea to Prusa)

Hi,

I like very much your solution. I was wondering if this this g-code impact the first layer adjust of the printer ? Why did you choose a 0.2 value for Z in the third line, is it related to your printer settings or does this value works with any mk3 printer ?

Regards.

Sébastien.

Posted by: @hansen

Since "day one" I have changed the intro/prime line in the start gcode so that it starts 5 mm above the print surface. This way the line will have a "tail" making it very easy - or at least easier - to remove from the build plate.

Specifically, I suggest Prusa changes the following start gcode lines in the Slic3r PE profile:

G1 Y-3.0 F1000.0 ; go outside print area
G92 E0.0
G1 X60.0 E9.0 F1000.0 ; intro line
G1 X100.0 E12.5 F1000.0 ; intro line


To:

G1 Y-3.0 Z5 F1000.0 ; go outside print area
G92 E0.0
G1 X60.0 Z0.2 E9.0 F1000 ; intro line
G1 X100.0 E12.5 F1000 ; intro line


(Z parameter added to the first and third line)

Now, that Slic3r PE edition automatically updates the printer profiles, it would be great if Prusa could do this change to the start gcode (so that I don't have to after each update 😉 ).

Anyone see any issues with the change?

What problem are we solving?

The OP seems to have a live Z misconception and wants the solution to be moving the prime line?

Damned if you do...

Posted by: @dan-rogers

The OP seems to have a live Z misconception and wants the solution to be moving the prime line?

I think the original original poster (@hansen) was just suggesting lifting Z from 0.15 to 0.2mm over the course of the first X move on the prime line. There have been several variations suggested since that 2018 post, including start position randomization. I did see an article about incorporating your signature into the prime line, or other pretty patterns. I have to say, it's mostly a non-issue after the PEI is used for a bit, IME. I've found extruding a "blort" of filament (purge bubble) before starting the prime line is effective at trapping nozzle ooze, so prefer to do that. I want it to stick better to trap filament, so leave it at the default 0.15mm after homing. This is definitely a case of personal preference, and I'm sure Prusa will get just as many complaints no matter what they do!