Intermediate Slic3r Setting Advice Needed

I got my Prusa Mendel kit recently I have been playing with settings and printing nonstop with 3 different filament types. It has a j-head Mk-IVB 0.35mm nozzle, Printrboard, Marlin and I'm running Pronterface with the latest Slic3r (XL Belts and printed pulleys). My red PLA seems to print really well most of the time but there are always issues now and then. I will take some pictures to show what I mean later on but for now maybe I can get some basic advice to perfect my Slic3r settings. I have attached a PrtSc of my settings, layer height is 0.25mm. I thumb sucked them for the most part so I am sure there are changes to be made.

The biggest problem I have is a distinctive line where the z goes up each layer. I also often have small blobs in random places and sometimes my corners kind of bulge. My supports seem quite messy but I haven't touched retraction. For the PLA I keep the fan going all the time as I'm not sure when it should be on.

Also on a side note what are the symptoms of backlash?

Edited 1 time(s). Last edit at 07/28/2012 04:08AM by RegionX.

Wow I at least thought I would get some info on backlash. Consider this a bump.

You'll have to post pictures of the issues if you want useful feedback.

If you have significant backlash inX and Y and print a circle, it will have flats, rather than being round.
Backlash is just where changing direction of the stepper is not immediately reflected in the motion of the printer. Usually a function of a loose belt.

Attached is a graph of what X backlash, Y backlash, or both look like when printing a circle, assuming a counterclockwise print direction.

I have graphed these with 0.05PU backlash to clearly show the effect, and the flats

-Rob A>