Anyone using Slic3r? What are your extrusion widt settings for the first layer?
Default. There’s practically no reason to change it.
@ThantiK Thanks. I hoped it would help with sticking the first layer to the bed.
It’s already at 200% as a default. Fix the problem at the source, otherwise you’re just compounding issues elsewhere.
Dead wrong. The whole reason that feature is there (I know because I begged and pleaded for it to be added to both Slic3r and Cura) is to help with the adhesion of the first layer. I set the first layer height to the diameter of my nozzle and the first layer extrusion width to 200%. This lays down thick lines of plastic that compensate for any inconsistency in the platform and give you a strong stick, while preventing the issue with blue tape where the plastic gets injected into the fibers and sticks permanently (ruining the tape). The wider extrusion lines act like the bottom layer of a raft, but they don’t need to be removed after. I figured out that this would work back in the days when skeinforge was the only game in town, and have been trying to get the developers of slicers to implement it ever since.
@Whosa_whatsis but the default is 200% already. In all practicality, there’s no reason to change it from that. I’m not saying that it’s an unuseful feature, there’s definitely a reason for having it. But telling him to change it would be like telling someone to change their bridge flow ratio, because their X/Y E-steps were off and bridges weren’t working.
Okay, that helps a lot. I was asking myself if I had set it at 200%. Couldn’t remember. @Whosa_whatsis I thought the trick was to print a thin layer very close to the bed. Never tried different. Does it also work with ABS?
@Rien_Stouten , Nah. Trick isn’t to print a thin layer close to the bed. That’s why there’s all those “First layer” options scattered about. You typically want your first layer thicker, and fatter so that things stick better without becoming incredibly difficult to remove.
It does indeed work with ABS and most other materials. You should have your “first layer height” set at something larger than your regular layer height. The bigger (within reason) the better. As @Whosa_whatsis stated, his go-to is to set that variable at the nozzle width.
Holy sh*t. That means I’ve been having problems for nothing. Keeps me humble, I guess.
Another reason to have a thick bottom layer is even the flattest materials are not flat. So If you have a .1 mm layer to start and your print surface (assuming with tape or glue or something on it) has a “flatness” of ±.02 (pretty dam flat) you are having 20% changes in layer height. If you use .4 it is only 5%. There are allot of reasons to print your first layer thick and heavy.
Should be obvious, but it needs to be said anyway. Layer Height should not be larger than nozzle diameter, for most of the print layer height should be <80%nozzle diameter (at least that is what i have read)
@ThantiK the defaults depend on your slicer. It’s good to see that Slic3r is now using this feature by default (I actually hadn’t checked Slic3r’s defaults for some time), but although I finally got @Daid_Braam to add the first layer extrusion width option, but it still defaults to printing them at the same width as all of the other lines, which means that if you make that layer taller, you’ll have almost no contact area with the platform due to the shape of the extruded plastic (or you’ll have to press the nozzle closer, which causes other issues).
I’ve been using 250% with all of my printers for about a year now with excellent results. I really like big thick fat layers for the initial layers.
I just wish slic3r would figure out how to do a worth while raft.
I actually have 250% in my Slic3r profiles as well.
This is an interesting topic to see. I’ve been doing it exactly wrong for a long time.
@Jon_Atkinson
@Jim_Wygralak
You are not alone.
Just started a print using my nozzle diameter as first layer hight. What I am seeing is truly amazing. Never thought it was possible to get such a perfect first layer. Second layer is a bit nasty, but that could because more filament swells up a bit more too. The effect gets less with each layer. I am so happy right now. Thanks guys.
Allright stopped the print, since it was for testing purpose only. First layer is exactly 0,35mm. Beautiful result. Print came of without effort. Previous prints with 0,2mm layer hight I had to use a hammer. Huge step forward.
You still want to make sure that you’re compressing the first layer the right amount. Ideally, the lines should just touch each other. If it’s over-compressed and the plastic mounds up between the lines, your second layer will be crap.
@Ashley_Webster 250% of the material that should be used for a typical layer of that height.
Yes, your maximum flow is the limiting factor I think. But… ( there is always a but) because of the thick layer, the adhesion is very good in my short experience. Normally I would print the thin first layer really slow, otherwise it wouldn’t stick, but yesterday, in my enthousiasm to try this, I totally forgot to reduce the speed. No problems at all. Very nice and smooth first layer.