I've recently installed an E3D V6 hotend on my prusa i3 and I'm experiencing problems with blobbing. What I mean is clearly illustrated in the attached picture. As you can see there are blobs that are formed at each entrance point to the stacks. These blobs come out of the hotend as it leaves one stack and moves across to the other one. When it reaches the other stack, the blob that was formed on its way over, comes off by sticking to the blob below it or to the actual stack. I'm using Slic3r with the retraction length set to 1mm and retraction speed set to 30mm/s. Although I've tried 3mm and 30mm/s as well as 1mm and 60mm/s. They have the same problem.