Jump to content
Ultimaker Community of 3D Printing Experts
Advanced

Print is unacurate in the first layer

Recommended Posts

Hello together,
I am using an Ultimate 2+ and we are printing just simple prints.

However I am struggling with following problem:
The first layer of the print is always bad.. On the glass as well as on a printed Build plate Adhesion (Raft).
The layers after the first layer look good, as well as the rest of the model. 
Do you know what I have to change? I am using simple white PLA with standard setting.
I also calibrated the printer again, with both calibration cards.

Is it maybe the file? we designed it with rhino 3D.

I look forward to your answer. Thanks alot in advance!
Fabian

 

 

 

 

 

 

 

IMG_20190114_131721.jpg

UM2+_EXBERRY Kaffeeschablone 60mm.gcode

Share this post


Link to post
Share on other sites

Hi Smithy,
I used the plastic card and second the paper calibration card at the 5 calibration points, and set the distance so that the paper between bed and nozzle have some resistance if i move it. Should be fine i guess?
However as you see in the picture, the bottom of the model is not accurate, but the top is perfect.

Could that be the file as well? I wonder why the printer is able to print a perfect adhesion plate, but the model then becomes that bad?
Do you have a test-print file which i could try to figure that out? 

Best,
Fabian

IMG_20190114_150119.jpg

IMG_20190114_150224.jpg

Share this post


Link to post
Share on other sites

It is possible that it is the model itself if the object is not lying flat on the build plate, you print in the air and if this is only a few microns then you don't see it on the first sight. But you can check it in Cura if you rotate the build plate to get a look at the underside. Check if the whole bottom is red, then it is actually touching the build plate.

 

To try another object is a good idea, download any object you like from Thingiverse, there are a lot of 🙂 

 

You can also enable the option "Automatically drop models to the build plate" in the Cura preferences, which should automatically put the object on the build plate.

Share this post


Link to post
Share on other sites

Actually another and fool proof way is to load the model into Cura. select the model and hit the move icon; the Z parameter should be 0 otherwise it is not sitting on the bed. Set it to 0 if not 0 . Also you could set it to -1mm (say) which means the model will below the build plate and try printing i.e. your first printing layer will be 1mm into the model rather than the  actual 1st layer of the model.

Share this post


Link to post
Share on other sites

Process:
I used this file to have a dummy -
https://www.thingiverse.com/thing:2400553

The first print looked like this:
IMG_20190114_165731.thumb.jpg.69153adfe7a927883207ed3a2bcad737.jpg
As we can see, there are first layer problems again.. I was thinking about the calibration distance.
I did the calibration again, but now with distance which is that low that the paper calibration card was almost stuck between needle and plate.. I would not say that this is a slightly resistance, more a aggresive resistance 😉
However the next trial comes out likes this:
IMG_20190114_171130.thumb.jpg.e8e8e55820349b29540c3b5f232bd33f.jpg
Way better I would say. Its printed without any "Build Plate Adhesion".
Tomorrow I will give it a next trial with my file, wish me luck.

 

@yellowshark thanks for your idea, I think its a better way if i find a good calibration first, before i set the Z to negative values. However if my attempt tomorrow will not work, i give it a try!

Thanks,
Fabian

Share this post


Link to post
Share on other sites

It will not help with your first layer problem if you set z to something negative, it helps if the bottom of your model is not flat for example. 

 

You have probably calibrated too high before, it is much better now. You should also clean your glass with alcohol, it is dirty 🙂 which could cause also adhesion problems. And I recommend to use a glue stick (UHU), make some stripes on the clean bed and then distribute it with a wet tissue to get a very thin layer of this glue mix. Then you don't need a brim.

Share this post


Link to post
Share on other sites

another way to check the z calibration on the fly is:

when printing the first layer, if you see irregularities, gently push underneath the bed, a little upwards. If the flow gets better, adjust the screws underneath the bed, looking top down, clockwise is bed higher.

Pushing too hard will result in very thin extrusion, there is a sweet spot between too thin, too thick. Just push the bed a bit while doing the first layer and look what happens, and adjust the screws accordingly. It also depends on what kind of model you print; a small surface might need to be closer then a big  surface, the calibration card is a general indication.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Our picks

    • Ultimaker Cura | a new interface
      We're not only trying to always make Ultimaker Cura better with the usual new features and improvements we build, but we're also trying to make it more pleasant to operate. The interface was the focus for the upcoming release, from which we would already like to present you the first glance. 
        • Like
      • 130 replies
    • "Back To The Future" using Generative Design & Investment Casting
      Designing for light-weight parts is becoming more important, and I’m a firm believer in the need to produce lighter weight, less over-engineered parts for the future. This is for sustainability reasons because we need to be using less raw materials and, in things like transportation, it impacts the energy usage of the product during it’s service life.
        • Like
      • 12 replies
×

Important Information

Welcome to the Ultimaker Community of 3D printing experts. Visit the following links to read more about our Terms of Use or our Privacy Policy. Thank you!