I've had my two Dremel Idea Builders for about 5 months now. When new they both were producing some amazing prints but slowly got worse over time. After countless hours calibrating, testing and even swapping out the PTFE liners (which finally solved my extrusion issues) I am still not able to get anywhere near the quality as before. I've tried every combination of extrusion multiplier, temperature, speed, infill, etc etc but nothing seems to get me close to the "good old days". At this point I'm leaning towards two possibilities...
1. Warmer weather. My most successful prints were done in the spring when the temperature and humidity were lower. I'm in Los Angeles so it never get's super humid but the ambient temp in my workshop is probably 10f warmer on average now. However my prints take on average 16-22hrs each so you would think that the day vs night fluctuations would have also wreaked havoc with the older prints as well if this were the true culprit.
2. Mechanical wear and slop. Maybe these units have simply started to get out of tune and the belts, rods, etc are just not as tightly aligned as before. I do semi-regular maintenance like lubing the rods, cleaning and tightening the bolts but nothing beyond that.
Here are two images. One is an "average" print from when I first got the Dremel. The other is the best I can seem to eek out these days. Any ideas you guys have are appreciated.