Why is my first layer wrinkled

[akkrolnik]

I am a new M2 user and have been printing successfully for weeks using PLA. Most parts have been small. Now I have graduated to larger parts and am starting to have some issues. I was reading some posts from others about warping on the corners of larger parts and saw some hints. One of them was to ensure the bed was level using the Simplify 3D bed leveling wizard. I thought this could be a contributor so I did it using paper to represent 0.1 mm. My original bed leveling was with a business card. By the way, I did find the leveling wizard to be pretty useful for those that didn't know about it. However, now I am seeing significant wrinkling of the first layer. (See the attached picture) The outer edges seem to grab hold just fine but the middle is not adhering to the bed. I figured maybe my nozzle is too close to the bed because this was not a significant problem before I leveled the bed using paper. Therefore I adjusted the first layer extrusion height several times making it as high as 130% before giving up and taking the attached picture. The original setting was 90%. Did I mess something up with getting the nozzle too close when doing the leveling? OR Is this just an adhesion issue and I need to start using hairspray as so many other posts have suggested? I saw a very small amount of wrinkling before I leveled the bed, but now it is very excessive. Also, I wipe the glass clean every time before I print something. I'm at a loss for what to try to fix this. Any help would be appreciated. If I just continue with the print the wrinkles end up causing nasty vibration as the nozzle passes over them. That can't be good for the nozzle. For that reason I want to fix this before I do any further printing.

Other details:
Printing PLA with 70-73C on the bed
Extruder temp 215C
Using simplify 3D with a 0.3 mm layer height
V3b extruder nozzle 0.35 mm diameter
Most other settings are default from Simplify 3D for fast printing

20150514_203801_resized_1.jpg

Picture of the wrinkles

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[jsc]

Getting your layer height and extrusion multiplier right fixes a whole host of issues. See the links here: viewtopic.php?f=3&t=2262#p12140 for an easy way to calibrate and set. You don't want to use first-layer-height for that, because it adjusts the extrusion to match. Instead, use the g-code offset (detailed in the second link).

If you are getting issues on one part of the bed and not the other, that is probably due to the glass not being perfectly flat. If you bring the glass up very close to the extruder, put your eye level to the glass and watch the gap between the nozzle and its reflection as you move the bed/X axis back and forth, you should be able to see it grow and shrink as you move it back and forth. Level the bed so that it is closest in the middle and falls off symmetrically towards each edge. Then when you go to set the Z height using either the Z end stop screw or the g-code offset, you can optimize to have it perfect in the middle, or take an average so it is slightly too close in the middle and slightly too far at the edges.

You will come to appreciate using an adhesion aid, like hairspray or glue stick. Hairspray (Garnier Fructis Extreme Hold is the best I've tried, on a recommendation from jimc) holds well and releases easily. For PLA, for me, glue stick (purple Elmer's) holds even better, but sometimes doesn't want to release so well.

[Jules]

Definitely give it a spritz of the hairspray - it helps to keep the plastic from warping up. And for PLA, I have had excellent results running the bed at a temp no more than 40 degrees. PLA needs to cool off immediately to keep from warping and curling - the hotter you have that bed, the more curling you'll get. The larger the piece, the more of a problem it is, since the fan doesn't cut in until the second layer, and it stays hot longer. But a slight increase in temp helps that first layer to adhere.

(Supposedly you don't even need to heat the bed for PLA, but it was walking around a little with no heat, so I keep it very low and use the hairspray.)

And like Jin said, if you haven't calibrated it yet.....do it. It's the most important thing you can do for getting good prints.

[PcS]

In a perfect world your layer height .3 would equate to a z gap of around .15. Anytime you change layer height and do not change z height it can effect your first layer adhesion greatly. You might try 90 first layer height and .24 or .20 layer.when it wrinkles usually you are putting to much down with a to close a nozzle.

[ednisley]

In a perfect world your layer height .3 would equate to a z gap of around .15.

Admittedly, I'm an outlier on this, but I set the M2 so that Z=0 with the nozzle kissing the platform. As a result, the first layer is exactly the same thickness and width as all the rest, unless you make specific changes in the slicer.

Two key advantages:

• Dead-simple Z coordinate measurement & adjustment
• The slicer automatically sets the correct width for any layer thickness

A longer description, from early in my M2 days:
http://softsolder.com/2013/07/26/makerg ... cal-setup/

I've tweaked many things since then, but the coordinate setup remains the same...

[akkrolnik]

Thanks all for the replies. I purchased a caliper and a set of feeler gauges yesterday. I will attempt to reset my bed height and perform the calibration before I do my next print. Hopefully I'll have time this weekend to do so and let you all know how it went. I'm still a little confused about the edges pull-up and bed heat topic. The default settings in S3D are 70C bed temperature for PLA. With my first roll of PLA (sent with the machine) this worked great. I was printing cell phone cases for my kids and saw no pull up of the edges at all. Then I bought some new rolls of PLA and started printing with white. I noticed the same cases (with minor tweaks to the snapping features only) started having a little pull up on the corners. I increased my bed temperature to 75 C and found it to improve the situation. This seems to be opposite of some of the recommendations I'm seeing on the forum. I've been stubbornly resistant to using adhesion aids and was thinking that bed temperature was the key. For the first 3 to 4 weeks I didn't use adhesion aids at all and had good success. A great advantage was when the bed cooled, the part would just pop off and I had no issues with material remaining on the glass. This seemed preferable to scrapping, chiseling and removing the glass to clean. I did a scrub of the glass (while installed) between each print and it was going well. I understand the importance of cooling on maintaining the dimensional properties as subsequent layers are built (especially with small layers), but does a higher bed temperature really contribute to or increase the likelihood of pull-up of the edges?

[akkrolnik]

Well, I've been able to resolve the wrinkling issue. It was completely due to the Z height calibration after I leveled the bed, just as PCS said.

...when it wrinkles usually you are putting to much down with a to close a nozzle.

I'm still having issues with the edges of parts pulling up. Even after I gave in to using hairspray. Admittedly I am just using whatever brand my wife had and not one of the recommended brands, but I will graduate to one of the recommended brands soon.

I played with different temperatures around the S3D default settings and proved to myself that the higher temperatures did not improve things for me as I had originally thought. Which clearly supports what you all have been saying. Here is my latest effort with the hairspray which is printing as I type this.

20150523_200329_resized.jpg

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Again the edge is pulling up. I have three more sections of this project so I will try the much lower temps recommended by Jules.

And for PLA, I have had excellent results running the bed at a temp no more than 40 degrees.

Maybe I am not spraying enough hairspray or the brand is wrong or the bed temperature is too high. So many things to test for a weekend warrior...

It seems bed adhesion is one of the sticking points to making 3D printing a less frustrating exercise. Maybe a precise hairspray metering device needs to be invented that can automatically spray the glass prior to each print with just the right amount of spray in a uniform pattern. Or a more universal device that can apply whatever substance works best for a particular filament type. To keep the creative juices going, maybe we need a new adhesion filament type that can be used with a filament splicer to apply an adhesive layer followed by the actual part. I saw a reference to Mosaic Manufacturing's automatic 4 color splicer. Maybe if one of those was an adhesion layer we could eliminate some of these print failure issues and more folks would benefit from the joys of 3D printing.

[jsc]

Get an Elmer's Disappearing Purple Glue Stick, in the jumbo size. Apply a layer of that across your bed as necessary. Poof, no more adhesion issues (with PLA). Washes off completely with water.

Hairspray gives a longer lasting hold, but the ease of application for glue stick is high enough that I can just apply it every few prints without feeling I'm gambling.

Also, with hairspray, brand does matter. Garnier Fructis Extreme Hold on a recommendation from jimc is the best I've seen, beating out Aquanet. The ingredients include polyester and polyurethane high in the list, so look for those.

If you really value ease of removal over 100% stickiness, you may want to try out Kapton tape. You should have gotten a roll with your printer. The 4 mil sheets from 3DXTech that Jules recommends here are easier to apply. I tried one out and it does work, but it was a bit too easy to slice into accidentally for me. You can scuff up the surface with a light abrasive like a Magic Eraser as Jules recommends to improve adhesion.

[Jules]

You can scuff up the surface with a light abrasive like a Magic Eraser as Jules recommends to improve adhesion.

Yep, highly recommend that magic eraser.....I finally figured out the perfect combination of anchors for PLA - I never have anything pull up now, no matter how large or small the contact area is on the print, but it does take a bit of prep work.

1. First is the Kapton tape. Full sheet. Well worth the expense because if you are in too much of a hurry to freeze your print off the plate, you can pry away at that stuff with a spatula and not damage the glass. (And you can toss the whole thing hot into the freezer for 15 minutes and any print comes off, no matter how large or round. Stuff's amazing.)
2. Use a magic eraser on the Kapton tape - all over, to give it a bit of tooth.
3. One heavy coat of hairspray - and by heavy, i mean coat that sucker so that you have liquid pooled on the tape. Then swipe it away with a folded bit of tissue, so that you have one even coat that covers the whole thing. Apply the spray cold, then set the plate on the heated bed until it is completely dry. That's the base coat.
4. Between prints, give it a light spritz (if needed) in areas where the previous prints might have thinned the base layer, but don't wash the plate in between prints - leave that base coat on for as long as it lasts. (Lasts through many full-bed prints.)
5. Also between prints, give it a quick once-over with the magic eraser on the dried hairspray layer. I just cut out a little block of eraser that lives right next to the machine now. It gives it sticking power above and beyond the plain hairspray. Wipe off the dust with a rag or your hand. (You won't see it, but it's there.)

I've had one print get knocked over because of a nozzle blob since I've started doing this, but none of them have ever had an edge curl up again. (If you're trying the glue stick and need some extra sticking power, you might want to try the magic eraser on that too....can't hurt. The secret I think is to get an even layer of whatever sticking agent you are using. And of course to get it to let go afterwards! )

[akkrolnik]

Get an Elmer's Disappearing Purple Glue Stick, in the jumbo size. Apply a layer of that across your bed as necessary. Poof, no more adhesion issues (with PLA). Washes off completely with water.

I bought some better hairspray and picked up some of the glue mentioned above. I tried the glue first because it seemed easier and less messy (with overspray etc.). It sure seems to be working. I'll try the hairspray again some time, and I'll keep Jules "fail-proof" method in my back pocket if I start having issues again. However, I'm kind of liking the glue stick.

Thanks to all who replied to this post.