Nozzle Caught on Blobs

Hello everyone,
Thank you all for a wonderful (more or less) first successful print! I have created a new extruder piece for my printer. While it turned out quite well, I've been having some noticeable issues with my printer dragging the hotend randomly across the printed part, which results in the nozzle getting caught on blobs left over by the previous layers. This causes a shift in the x or y axis, and the Leaning Tower of Pisa is born. Is this a problem with my slicing software? Thanks!

Which slicer is that? Slic3r has "Z-lift" setting, try 0.5-1mm value.

Hey pkm, thanks for the quick reply. I'm using Slic3r, and I have Z lift enabled on layer change for 1mm. It did fix some problems when I turned it on. However, this does nothing to combat the nozzle running into blobs in the middle of the layer print.

You need to find out why you get blobs in the first place, and correct that.
Overextrusion?
To short/slow retractions?
Need for coasting/wipe?

Edited 1 time(s). Last edit at 09/07/2015 02:50PM by Koenig.

Did you calibrate the angles of your towers? It might be that an opposite position of a tower is too low, which blocks a small amount of flow of filament and results in over-pressure on your nozzle and makes it leak when it stops the motion.

Are you using Repetier firmware, or Marlin, or something else?

On my system, I discovered that Repetier was very susceptible to noise on the endstop lines, especially during extruder retractions.

When Repetier would get a 'mistaken' endstop signal during a print, it would prevent the tower's stepper from moving, causing a X/Y slide, and a small loss of Z. Too many of these events, and it would translate into too much Z loss, and the head would crash into the print.

Make sure that your endstop cables are separately routed from any 'fast driving' cables, such as stepper motors and PWM controlled heaters.

Also, twist them if you can - that will help reduce the noise they pick up.

I'm using Repetier firmware, and just a minute ago my printer started giving me a calibration nightmare. The nozzle is perfectly level with the bed in the center and in front of my Y tower. In front of the X and Z towers, however, the nozzle is some 2-3 mm off the bed! What is going on here, and how can I fix it? BTW, does anyone suggest using Marlin or other firmware? Thanks in advance!

Can't you just move the endstop down?
The center will be lower, and you will need to adjust the delta radius.
That's how i did it in Marlin, i assume you can do the same in Repetier