PLA not sticking

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Dale Reed
Posts: 376
Joined: Thu Apr 10, 2014 1:39 am
Location: Cleveland Heights, Ohio USA

Re: PLA not sticking

Post by Dale Reed » Sat Aug 16, 2014 6:29 pm

I'm not at my printing PC, so I'm not sure which tab it's on in the FFF "show advanced" mutli-tabbed box --- but there is a set of X, Y and Z Offsets. They should all be zero. Make sure the Z entry is not a positive number --- that will make the print start that much "above" the bed.

I tend to level my bed a tad further than most people, then use a small NEGATVIE Z offset in the G-code to print closer to the bed. I'll level with a sheet of paper so it doesn't drag between the nozzle and glass when cold. Not "lightly drag" but NO drag at all. My Z offset for this is ALWAYS less than 0.1 mm.

In your case, I'd try entering a SMALL NEGATIVE Z offset before slicing -- maybe -0.05 mm to start --- and see if it prints better. The idea is for the nozzle to "smoosh" the plastic onto the glass rather than "drop" it on. You want adjacent threads to meld together into a single flat layer, not coil "near" each other like coiling a rope or cable. By "smooshing" slightly, the threads in a layer a pushed out sideways just a tad so they form more like a coil of "rectangular" rope rather than round rope.

I hope you understand what I'm going for. I could draw it on a whiteboard for you in about five seconds....

Anyway, try that small negative Z offset. If it helps a little, offset more. If the nozzle starts to drag and make a real mess, lose the offset.

Also, check your extrusion multiplier. Might be too low. Typical numbers for the M2 with PLA are about 0.95 (95%). If yours is down closer to 0.90, bump it up. Should not need to exceed 1.00, however.

Hope this helps! Let us know!

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