First layer speed and z adjustments
So I'm pretty sure there isn't any way to do some of this but just seeing if anyone with more knowledge than me has figured it out.
Situation: I make a variety of custom items that are made out of PLA on textured sheets. The use of textured sheets is for cosmetic reasons. Many of the products have designs on the first layers (names, logos, etc). As we all know, PLA on textured sheet can have first layer adhesion issues. In particular the perimeters on the detailed items have issues since they are not one long continuous perimeter.
To get around this issue I keep the sheet as clean as possible and then for the perimeters I often have to slow the speed way down (as low as 50% of first layer speed) AND I find that lowering the live-z by up to 0.03 units is often necessary. The live-z at that level is usually too low for the solid infill of the rest of the object...you get that wavy texture which I don't want...and so I have to raise the live-z back up. And the speed at that lower speed increases the time significantly so I try to just adjust speed for only the crucial perimeters. So I have to be present and timely when I adjust the speed and the live z. Miss my timing and I'll often have a print that isn't acceptable.
Question is whether there is a better way to do this? Would be great if PrusaSlicer let us manipulate feature speed for the first layer beyond just the global first layer adjustment. I would be happy doing it with custom gcode but I don't think there is a way to just apply it to perimeters. I can use a modifier mesh (and do) to adjust perimeter speeds for the first layer, but that is a little clunky. And I have figured no way to adjust the z-offset (or live-z) other than by hand as the print is running. Z offset by feature for first layer would also be a fabulous PrusaSlicer adjustment to have.
Any ideas? Thanks in advance.
RE: First layer speed and z adjustments
@rickm-2
You can manipulate feature speeds for the first layer, just like any other layer, but you have to remove the cap speed (First layer speed: 20mm/s) by default. Use a percentage value instead, First Layer 100% for example, then set a (height range modifier) for your first layer, let's say your first layer height is 0.2 set the (HRM) layers 0.0-0.2.
Then add modifiers for speed.
External perimeters:
Perimeters:
Solid infill:
If you have Small perimeters in your models add them also.
and change the speeds for the first layer from there, in this way you can leave the settings for the remainder of the layers intacted.
Now that I've told you this, have you considered increasing the extrusion width for the first layer? by default its 0.42 for a 0.4 nozzle and turning it up to 0.45 may very well help.
As well you may also consider using something like Layerneer Bedweld, or Magigoo they can increase the adhesion to a better then acceptable limit on the textured sheets if your having problems, I might normally suggest Elmer's disappearing purple glue stick to help, however Layerneer and Magigoo have better repeatable performance per application, and it sounds like you might be doing production runs.
Anyway, hope this is of some help to you.
Good Luck
Swiss_Cheese
The Filament Whisperer
RE: First layer speed and z adjustments
Hey S_C,
All good ideas, thank you. And you are correct in that this is me trying to streamline a process for certain items. I use HRMs AND modifier meshes on each of these items but have to confess I hadn't tried using HRMs for the speeds, not sure why. I think that would indeed be less clunky to apply to all items in the 0-0.2mm range rather than the more specific modifer meshes I use. I may switch between the two depending on time constraints. Thank you for the idea.
I do use 0.45mm extrusion widths on layer 1 as I had found the same as you that it helps a little. I have never tried the adhesives I will have to try and see how I like those from a cleaning standpoint I guess. I do have a BCZAMD textured sheet to try out as I know some people claim better adhesion.
Overall prints are great, just would love to find the happy medium where I'm not trying to adjust live-z on multiple machines while doing other work. Frustrating to miss making the adjustment by a couple minutes then having to wait 4 or 5 hours to discover the detail perimeters lifted and aren't perfect.
Hopefully PrusaSlicer devs will give us a little more control over first layer speeds and z offsets at some point.
Thanks for your ideas!
Rick
RE: First layer speed and z adjustments
All of Swiss_Cheese's suggestions are good ideas (of course), all I would add is to encourage you to try the BCZAMD textured sheet. It's the only textured sheet I use on my printers, and they work much better than the Prusa sheets, at least in my hands. Also, if texture is important, maybe the satin sheet is a reasonable in-between? Not as coarse as the textured sheet but hides lines more than the smooth sheet. And like the BCZAMD sheet, at least for me it works flawlessly with anything I throw at it. For small first layer features I also second the suggestion of using Layerneer.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: First layer speed and z adjustments
@fuchsr
Yep, agreed, I've always thought Swiss_Cheese has good ideas but that's gone for you as well. And given that both of you suggest Layerneer I went ahead and ordered a bottle and will give it a shot. You guys apply before each print and then clean off after? Looks like it's water soluble.
I'll definitely bump up the priority of trying the BCZAMD sheet I bought if you've had good luck with it.
I did purchase a few Satin sheets just for the reason you suggest and though I do like them (great adhesion) I prefer a little more texture to hide the layer lines on some cosmetic pieces. I do use them on some however. Could be I just need to experiment more with them as well, of course.
Thanks for the suggestions!
RE: First layer speed and z adjustments
I don't use Layerneer all the same, only rarely for cases that even the satin sheet can't handle. A thin layer is enough, and frankly, I don't clean it after each print. If I print the same thing multiple times, I may just put another layer on. Heresy, I know, I know... And then when needed, take it all to the sink and clean with hot water and soap.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE:
The satin sheets are my favorites, however Layerneer works extremely well for the original textured steel sheet, relative to the Op's issue, I could write A whole paper on whats good about the satin sheets, but I have experienced the problems with the textured powder coated steel sheets first hand, I have 2 that are good and one that's worth shit. The first one I received. I use Layerneer and/or Elmer's disappearing purple glue stick on it, and it works great. I conclude that there was a transition period in the development of the powder coated product, that they (Prusa) weren't willing to admit. Anything beyond these early products seems to work wonderfully. I own 3 of these only one being from the early period. while I understand that Prusa recommends not using glue products on these sheets, they are full of shit. this is why we have a community. I am ridiculously well versed in the usage of this software and hardware, Sheet product as well. if your having problems with adhesion regarding a Prusa product use an after market product. do not believe that Prusa is about your well being. do what you need to do to produce what you need. All this said Prusa is still one of the best results out there, other companies are not offering this level of support , keep this in mind as you. yes period, decide to participate with the community. it's important to be real
Realgards
Swiss_Cheese
The Filament Whisperer
RE: First layer speed and z adjustments
Thanks guys. I appreciate the input and will definitely try the layerneer and experiment further with the satin sheets and aftermarket sheets.