I very nearly quit. I've read every troubleshooting post since July 2013 in the hopes I would find something to help me. I posted a couple of times and you guys were amazingly supportive. But the problem turned out to be a bad part and it's amazing to me how something so small could result in such bad prints.
Here's my story:
After over a year of failed print after failed print, taking my machine apart and rebuilding from scratch 4 times (last time to replace with tricklaser melamine and tricklaser print arms). After frying the Rambo board (I had a short)
After buying and giving away kilos of what I thought was bad plastic (even the neon green from SeemeCNC). After printing out an average of 20 calibration cubes a week (changing one thing and printing again). After altering temps by 5 degrees, slowing prints down to 5mm/sec, IOW trying every single suggestion I've seen posted.
After the people on this board spending their time trying to help me (thank you, thank you, thank you, btw!)
I've finally figured out what what is wrong, and fixed it.
Some of the problems were mine, (tricklaser arms are 270mm not 269, and don't fry your electronics), but two were SeemeCNC quality control issues (I purchased my kit in before March 2013) and they were remarkably hard to pin down and fix.
1. My Onyx bed heats up so warped that when it is at temperature (95-100C) the area between 1-2 o'clock is 0.5cm different than the center of the bed. Fyi: its opposite side, 7-8 o'clock is the same as the center. I finally heated it up, and shimmed it. It is about .1mm off now. So after that, I could move on. But after massive calibration trials - here's the best I could do. This is protoparadigm ABS averaging 1.75mm, 215 degrees, half speed, otherwise SeemeCNC recommended Slic3r ABS settings.
Fyi: cube is 0.75 high but otherwise same dimensions - got tired of wasting plastic.
That was the *BEST* print I ever got. I also tried MHackney's Kisslicer settings and Cura. Same or worse.
2. This is the killer: Apparently some of the .5mm nozzles sent out with the kits were really not .5mm -- after reading the whole post and threads about Xaron's magnetic arms, at one point he mentions his nozzle being mislabeled. He said that printing into the air the strand diameter was about .8-.9mm not .6 where it should have been. So thinking I had nothing left to try, I printed into the air, measured it and so was mine. So, I pulled the .5 nozzle off a friend's printer and tried it. Look at this print - I didn't change a thing, except the nozzle.
Sometime during this whole thing, my LCD panel stopped working (just square blocks, and now nothing) so I'm going to have to spend more to replace it. UGH!
A last major thank you, this is a great board is full of amazing people.
Anyway: If your cube has gauges or arches and lots of loops plastic in the center - check your nozzle size is correct.
I bet it feels great to have it running like you know it should!