Having trouble getting first layer support to stick

4

I'm having an issue where the first layer of my support structures isn't sticking on the edges and causing the print to (eventually) fail. Any ideas on how I can fix it?

I'm using Slic3r.

Photograph of first printed layer

easycheese

Posted 2017-04-23T17:30:35.137

Reputation: 407

Answers

3

There are many things you'll need to check and/or confirm to ensure that you will have a good bond to the bed. The first is to confirm that you are using a genuine Prusa printer as it appears in the photo. Having built one recently makes it easier for me to guess that is the case.

Have you performed the bed calibration sequence? The manual provides a series of steps which results in a zig-zag pattern of filament being placed on the bed, while the z-height is adjusted from the panel. You want to have a filament trace that is only slightly squished onto the bed, not flattened so much that it's cutting into the PEI and not so high that it's nearly cylindrical.

The bed must be of the correct temperature for the filament selected. If in doubt, raise it five to ten degrees C. I recently assisted with the aforementioned printer that had a peeling problem and the bed temperature had to be raised to 70°C from the "standard" 55°C generated by Slic3r.

It is critical that the bed be clean as well. Denatured alcohol is recommended, with application of a clean cloth.

Your photo is somewhat out of focus, making it difficult to determine if the brim is being created at an excessively high z-level, which will cause peeling. The main body of the print, also out of focus appears to be heavily flattened, but that could be an artifact of the photo.

The reflections on the bed appear to indicate that some gouges in the surface exist. If your PEI is damaged, you will have the problem you described. I've seen videos in which the bed is not quite as gouged and was refreshed with very light sandpaper or very light steel wool or both. Of course, after using such material, clean the surface thoroughly.

I understand the PEI that is applied by the manufacturer is quite thin and can be further damaged if too much pressure is applied while refreshing. It is far better to apply too little pressure if you plan to perform this task.

Consider to read through the manual and address all of the calibration aspects of the printer to establish a base point for the problem you are experiencing.

fred_dot_u

Posted 2017-04-23T17:30:35.137

Reputation: 8 399

>

  • It is a genuine Prusa. I adjusted the bed temp up to 70 (from 65), sanded with 0000 steel wool (cleaned w/71% isopropyl alcohol). and recalibrated (I think this was the primary issue, i always wanted it to be squished more than it's supposed to be, perhaps squishing it so much was causing it to stick to the side of the nozzle and then get peeled up on the 180). It appears to be working now, thanks! Also, great list of things!!
  • < – easycheese – 2017-04-23T21:23:52.547

    1

    If you are using PLA, putting blue painter's tape down on the print bed will really increase adhesion. You can also lightly sand the blue tape with a piece of fine sandpaper to further increase bed adhesion.

    Brendan Smith

    Posted 2017-04-23T17:30:35.137

    Reputation: 307

    Yeah but this shouldn't be necessary with a heated bed. – easycheese – 2017-04-25T13:00:09.130

    I use both painters tape and a heated bed. I agree that there may be something else off with the print, but painters tape is a very good suggestion to start with. – Diesel – 2017-04-25T13:14:38.983

    My experience with the aforementioned Prusa is that the PEI is quite a good bonding surface if properly treated, cleaned and not damaged. Additional adhesives may be needed for "exotics" but typically not PLA if all other factors are correct. – fred_dot_u – 2017-04-25T21:39:08.967

    1Easycheese is correct. I've heard that painters tape actually worsens bed adhesion on heated beds, but I can't test this out to confirm it because my printrbot doesn't have a heated bed. – Brendan Smith – 2017-04-28T13:45:35.990

    1I'm not sure where your information is from but I've used a heated bed for the past four years and my prints have significantly improved adhesion using painters tape. That's using standard materials like PLA and ABS – Diesel – 2017-05-01T17:53:54.620

    0

    I had a similar issue where slic3r generated supports that attach directly to the bed, but didn't put enough material around the thin supports on the first layer, so they didn't stick to the bed.

    To solve this I added a brim, see "skirt and brim" under "print settings". This puts more material around both the part and also the supports on the first layer.

    I didn't need the brim round the whole part as it was sticking to the bed just fine anyway, but this was the only way I could find to give the thin supports the wide base they need to stick to the bed. I used a 5mm brim, but I am sure it would work with less than this.

    EmbeddedSoftwareEngineer

    Posted 2017-04-23T17:30:35.137

    Reputation: 1