Question about perimeter seam

[MikaMa]

Hi

I have tried to minimize the seam and have gotten pretty good results, but I have a few questions for the wiser folk. I usually calibrate the seam with a rectangle object and see how the seam gets printed. After that I adjust coast, extra retraction etc. Untill I'm happy with the results. If I'm right the seam can not made to disappear but it can be minimized or hidden.

My problem is that the results vary a lot between different objects and I don't understand why. Rectangle has a minimal seam, object like a small skull is ok also but a lizard figure was over extruded where the seam is. Then I printed the rectangle again and it was fine.

Is it really this complicated or is there something I just don't get? I thought I was getting pretty good with adjusting the settings but can not figure out why the retraction settings give so random results. Any tips are welcome

[jimc]

it can vary due to many things but the most common is the length of the travel move. your rectangle might only have a travel move of 1/2-1mm where other models might have to move from one side of the bed to the other causing a longer period for the filament to ooze. another thing that can make that seem hard to control is moisture. damp filament oozes more. plastic type as well. some plastics are more runny than others. too high of a temp, no enough retraction can also enhance the ooze. the more oozy a filament is the more erratic the blobs can be from a travel move.

[MikaMa]

Thank's Jim. My filament is as dry as I can get it. When I get my filament I dry it in oven and move it in a sealed container with desiccants and the humidity is around 15% in the container.

There are indeed a lot of factors to handle..