Extrusion blob before layer change

[Nicolinux 288]

Hi,

I don't know if this has been asked before but I noticed that very often before a layer change, the head pauses for a fraction of a second, extrudes way too much plastic before it moves on. I don't think it is related to this:

http://umforum.ultimaker.com/index.php?/topic/2786-please-analyze-my-prints/?p=20288

I have the feeling that it is a "deliberate" action and not related to too much presure. The squashed blobs look like this:

To avoid it, I think it would suffice to move inward a little (where the infill area is located), do the overextrusion and then move on. If this is on a top-layer that it is problematic...

 

[illuminarti 18]

There can be a couple of causes of the blobbing. Firstly if the printer is retracting, that takes time, and there can be some net extrusion before the retraction kicks in. You'll want to make sure you have recent firmware and refine your retraction speed and distance, to make it happen as quickly as possible.

Secondly, you need to tune your z-speed and acceleration settings so that layer changes happen as quickly as possible.