lifting on first layer? First Printer  

Re: lifting on first layer? First Printer

First off the bed is amazingly flat. Congrats.

Second, it's hard to tell if the filament is too thick in those lighter areas, or, too thin. If they are too thin, there will be lines of "excess" material running along the extruder path where too much material is being extruded, and it squishes out on top the last pass. Too thick and the extrusion will not stick to the PEI and tends to ball up in clumps.

Any lighter areas that look roundish are most likely finger prints, or other contamination, and the PLA isn't sticking well. PLA is exceptionally sensitive to oils, and they cause all sorts of print problems. Consider the PEI sheet a hands off area.

Lesson One: NEVER touch the PEI sheet with your fingers or anything that can carry finger oils. Dedicated plastic spudgers are best for removing printed parts.

Lesson Two: Get a routine washing process down. Hot water and detergent like Dawn works best (no additives like anti-bacterials). Wash using fresh paper towels, not a used disk rag or sponge. Rinse well in hot water, rinse more if you have soft water. Dry with fresh paper towel. Place sheet on printer, handling by the edge, then rinse with 91% or better alcohol (pour a small 10 cm puddle of alcohol on sheet), scrub then drying with a another fresh paper towel. I cut paper towels down to do the rinse. Then, with clean and dry hands, use a fresh towel lightly dampened with alcohol so it evaporates fast as you wipe, wipe the bed in strokes, back to front: if you see any streaks you need to do more cleaning. As the PEI ages, it oxidizes; you'll use acetone to clean off this residue and refresh the 'stickiness'.

Lesson Three: Keeps all body parts away from the PEI sheet... you'll learn that prints show up at the most inconvenient of times.

Lesson Four: PETG and ABS and other filaments are not as picky, and you'll use things that contaminate the PEI to keep the print from sticking too hard.

A few thick spots won't hurt anything; nor will a few thin spots. The 3x3 bed level function isn't perfect, and the PEI sheet isn't perfectly flat, so some areas may be high, some may be low. There are ways to address this, but they get tedious and will require some reading in these forums and elsewhere (I use the 7x7 cal method).

ps: you can drag images into the forum text window and they become attachments. Better here than 3rd party sites. And a gcode file is mostly useless for debugging; stls are better, and can be uploaded by placing them in a zip file before dragging into the text window or attaching via the upload tool.

Re: lifting on first layer? First Printer

First off thank you very much for the detailed reply and suggestions for the issue I was running into and the suggestions on the forums.
All very welcome.

I believe you are 100% correct, I've looked at some of the other pictures that I took and there were visible finger prints. Once I did a through cleaning the filament stuck perfectly.

Thanks again. (One lesson learned, many to go)

Now if i may ask another question.

Oil/Dirt on the top X rod.

( see attached)
The question is, is this normal or did something go wrong during the assembly?

If I should start another thread I'll gladly would.

George

Re: lifting on first layer? First Printer

Cool; glad the printer is working again.

When you assembled the printer, did you grease the bearings before inserting the rods?

If you answer no, then plan a maintenance disassembly to add grease inside the bearings. They ship with an oil preservative meant to deter rust during shipping; that oil is useless as a lubricant. The oil needs to be cleaned off and grease added. Like car wheel bearings, grease is essential to linear bearing life. I didn't think to grease mine and had to replace them at 2000 hours.

That black residue is the grease seal wearing, no grease, more wear on everything. A well greased bearing will show some seal wear, but much much less than what you are seeing. On my second set of bearings I used Superlube Synthetic with Teflon. Others use White Lithium mineral soap based grease like LithEase. Any grease is better than no grease. If you only have Molylube, use that. Just be sure you wipe the insides of the bearings to remove the shipping oil before adding the grease.

A few drops of sewing machine or 3-in-1 oil on each rod will help save the bearings until you have time to do it right.

Re: lifting on first layer? First Printer

I wanted to close this correctly. I did as you suggested, first 3 in 1 then with grease. Everything is running smoothly now.

Thanks for your help, much appreciated.