first layer temperature

[classicvideogamer]

Hi,

By default my first layer temperatures seem to be 70 for the bed, and 215 for the extruder. But if my Initial temperature is closer to the recommendation, (60 for the bed, and 190 for the extruder for PLA). What I would expect to happen would be for the print temperatures to be only 70/215 for the first layer, and then go down to the recommended temps (60/190) for the remainder of the print. I'm I confused about this ? How do you guys usually have your temperatures set ? Thanks

Jeff

[Jules]

The defaults have to be something that will work in every possible scenario, but they don't necessarily give the nicest output. (Impossible to set one "best" default for each individual's location and ambient conditions.)

For me, the defaults are set way too high, but I don't have a basement, and for all I know, the higher temps might be completely necessary in a cold room. I typically use 60°C all the way through for bed temp, and about 205°C for the extruder temp on the MakerGear PLA. (That's in a 76°F room though.) Don't have a bit of trouble with the filament bonding or sticking to the plate.

To get the best settings for your location, you need to experiment a little. If you've got it in a temperature controlled environment....try the lower temps.

Just change the temp settings to the lower numbers, try a few prints, and if it works, either save the profile under a different name or update the default. If it doesn't bond, increase the temps by 5 degrees and try again.
Or if you want, you can change the temp for the second+ layers by adding another temperature setting in the Slicer software, but that's a bit overkill for PLA. (It is necessary for some other filaments.)

We spend a lot of time in the beginning experimenting with settings to improve the quality of the prints, but that's going to be totally different in my south Texas office and someone else's 56°F basement. The default will work for everyone, but it's likely to give you the least attractive results, depending on the conditions where you set up your machine. (I found that to be the case and got away from using the defaults, ASAP.)

Really just depends on how much time you want to spend improving the quality of your prints, it will keep printing just the way it's doing now at the default temps, so if that's good enough for your purposes, no need to change anything.

(Plan to burn through about half of that roll of PLA that came with your printer though, while you learn what works and what doesn't. It's why they include it.)

[classicvideogamer]

Thanks Jules.

[classicvideogamer]

I'm pretty much having the below issue with anything I print now :

https://www.dropbox.com/s/uaae3qxyi3th4 ... 2.jpg?dl=0
https://www.dropbox.com/s/x1zad4k8hbi8s ... 4.jpg?dl=0

Most of the 1st layer seems to go down ok, but there always seems to be a few strands that end up not adhering to the glass well enough & then causing issues later on.

Any ideas on what I should focus on changing ?

[willnewton]

Ok, you are beyond a bed temp issue. Those first layers are just wrong. That is not even close to what the M2 is capable of. Don't worry, it can be fixed.

You need to consider that you have a clog, and/or under extrusion , and incorrect z-height.

Go ahead and boost your print temps a bit to about 205-210 as well.

[classicvideogamer]

I have some cleaning filament I'm going to run through, not. Sure if it will help at all, then I'll take some pictures of my z height, once in some shuttling the kids to soccer. Thanks.

[willnewton]

First, get your z-height straightened out. You need to be laying down a flattened rectangle of filament, not a round layer or an overly squished layer.

I know there are many ways to get the filament to stick better, but just start with some wide blue painter's tape on your bed, just to help get you on the right path.

If you have Simplify3d you can go to the g-code tab and change the z-offset in .05mm increments to fine tune your starting height. Start with -0.10

Switch to a simple 20mm cube to diagnose these issues and make one change at a time. Your filament lines should be laying down right next to each other with no gap. You don't need to print the whole thing, half of layer one is good enough to start diagnosing issues.

Cleaning filament is probably not going to clean your nozzle. It is more often used as a transition filament between filaments with differing printing temps. There are many nozzle-cleaning guides available via search. viewtopic.php?f=3&t=2942

[Jules]

Yeah, i totally agree with Will here.....the gap is too large between the nozzle and the bed for the first layer. Quickest (short term) fix will be to cover the plate with Painter's tape. That will shrink the gap enough to get you a good bonding between your extruded threads.

An alternative would be to determine your corrected Z-Offset using the calibration procedure here:

viewtopic.php?f=3&t=3124

And you might want to read through the Beginner's Guide for the M2 (not the M2 Rev.E) here, it discusses all of these issues, and helps with determining what is causing whatever problem you might see:

viewtopic.php?f=3&t=3342

[classicvideogamer]

I guess the good news is that my kids soccer games got cancelled due to some expected snow (Philly Area). Now I have something to do (read guide), apply some painters tape, and also in the middle of a calibration test - that I started before I saw the previous post (so much to learn). Thanks for all of the help guys.

[classicvideogamer]

very minor update -

5mm calibrtion cube

don't really know enough to interpret the results of this yet.

https://www.dropbox.com/s/5i4e90590rg8f ... 8.jpg?dl=0

Off to read beginner guide to getting started & then try to print something with the tape on my bed.