small Blobs/Ridges at corners and randomly on surface?

I have a Prusa I3 box frame, I do not know the variant. She has been printing really well for a few months now. I have been trying to get it dialed in to perfect though. One of the things that is still driving me crazy is that I get blobbing sometimes at the corners and sometimes just randomly.

I am using Cura for my slicing. Please let me know any other info that you would need to help me fix this issue.

Attached is a pic of the test pyramid and the ridges/blobs.

Increase retraction and lower your temperature.

I forgot to add, I am currently printing at 175c at 40mm/s with a 0.4 nozzle. I thought 175c was pretty much the lower end of what you should print PLA at?.?.?.

My retraction is set at 40 speed, and 4.8mm distance.

Edited 1 time(s). Last edit at 04/26/2015 03:19PM by windcalmer.

You are right, 175 is quite low, and 4.8 is high retract setting for a direct drive. So that isn't the problem. Play with acceleration and keep settings.

It is a wade extruder. I am about to print a few tests so I will post the results after I turn down the acceleration. Thanks for the help!

O.K. Turned the accel down a bit, still the same problem. On a hunch I tried slicing with Sli3r instead of Cura. All fixed. I have the same profile loaded to Cura as I do Sli3r. The very same settings. Is there that much of a difference with the two?

PIC:







Also, I am getting nozzle drag on my first layer no matter what slicer I use. That is an E-Step problem right?

The best way to find out the differences is to compare both g code files, most likely is in the acceleration-deceleration and extrusion (compare F and E values).

Regarding the drag issue, it can be several things: bowed bed, natural bend of the linear rods specially if they are 8mm, e-steps if you haven't get it set correctly. If the drag occurs in the middle of the plate, 1 and 2 might be at play, if on one side can be that your X axis isn't level and that side is lower or one motor is not as powerful as the other (not usual but possible) and moves at different rates and of course if your e-steps are incorrect, 0.1 will never be 0.1.

So i releveled the bed with a much thinker piece of glass and got my heated bed hooked up and running. The nozzle drag is still there, and now i am having issues with parts not sticking. Most do, but two out of 13 prints this weekend popped off.