Jump to content
Ultimaker Community of 3D Printing Experts
Sign in to follow this  
braddock

First layer question

Recommended Posts

Hey guys, I've been keeping an eye on this for a while, and ever since having a few layer shift issues, I'm paying more attention than usual to certain things, looking for belt slip or other things.

My first layer usually looks like this, a slight gap between each line that goes down... usually by the time the 1.2mm bottom is complete, it's nice and smooth, but is it normal to have these gaps between lines?

 

first layer

 

Share this post


Link to post
Share on other sites

I don't know if this helps but i found that printing the first layers a 230°c gives a better result. The lines are more pressed together.

I don't think you have a levelling issue because your brim looks good to me

 

Share this post


Link to post
Share on other sites

First layer looks good, second layer has unexpected gaps. Is your infill set to 70% or something? Did you change flow to less than 100%?

Some people have overextrusion on first layer and fix it by lowering flow to 90% instead of lowering the bed by 10% of the first layer thickness.

This looks like typical underextrusion on a UM Original, but underextrusion on the UM2 tends to have sudden slip backs of the feeder such that you have obvious spots where there is zero extrusion. This more looks like something on purpose such as the first two things I mentioned.

 

Share this post


Link to post
Share on other sites

Well, the brim is perfect, so I don't believe the bed needs leveling. These layers were at 240 - 0.08 layer height.

It's not under extruding, the rest of the print is perfect, walls are perfect. I had this printing at 50mm/s when I slowed it down, the gaps went away.

I've not changed the flow at all.

 

 

Share this post


Link to post
Share on other sites

To clarify, it's not under extrusion as I know it on the UM2, it's consistent, and has no negative effect on the rest of the print.

The consensus from you guys though, is that it is flow / extrusion related and not a mechanical loss of precision.

Perhaps with this filament I could try increasing the flow on the first layers.

 

 

Share this post


Link to post
Share on other sites

The consensus from you guys though, is that it is flow / extrusion related and not a mechanical loss of precision.

 

 

Yes. Mechanical issues look different - typically two close together lines and then a gap and then repeat.

 

Perhaps with this filament I could try increasing the flow on the first layers.

 

Better to print slower. Are you sure these gaps aren't on purpose by the slicer? Maybe open the gcode in repetier host (it's free) and see if it also thinks there are expected gaps?

 

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
Sign in to follow this  

  • Our picks

    • Taking Advantage of DfAM
      This is a statement that’s often made about AM/3DP. I'll focus on the way DfAM can take advantage of some of the unique capabilities that AM and 3DP have to offer. I personally think that the use of AM/3DP for light-weighting is one of it’s most exciting possibilities and one that could play a key part in the sustainability of design and manufacturing in the future.
        • Like
      • 3 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!