Improving Print Quality

[dale 0]

Looking for ways to improve print quality - namely, the shrinkage in the early layers and the horizontal striations moving up the print. Using Colorfabb PLA.

[valcrow 145]

I would drop "initial layer thickness" to whatever your layer height is. Just be sure to level correctly and it'll get rid of the elephants foot at the base.

I find, if the difference is too great between your infill speeds and exterior wall speeds, you get inconsistent walls.

I would drop speeds to the following:

infill - 40

outer shell - 30

inner shell - 35

If you have lots of time to kill and are just going purely for quality, make everything 35. You can probably increase your layer height a bit to compensate.

Lastly, white is not a good colour for this kinda thing. White has always been the most inconsistent colour, making z-striations the most visible.

[geert_2 558]

In addition to the above of valcrow, if you have even more time available, way more time, you could drop speed to 20mm/s, and nozzle temp to 180°C or 190°C for PLA.

Buildplate temp: max 60°C, but if it still bonds, you might try 55°C too. This reduces sagging.

Also, if the filament is wound up too hard (near the end of the spool), straightening a few meters manually might help a bit too. Then you won't get irregular filament movements when the machine has to pull harder at some places to unwind it, and to force it through the bowden tube and nozzle. A more consistent flow = better quality.

Rather than one big thing, it might be a lot of smaller things.

Try this on a small sample first. Not on a 2 day print...

[gr5 2,237]

The "shrinkage" is caused by the heated bed. The pla is not cooling enough there and it's still soft when the next layer goes on top. The outer layer is going down as a liquid rubber band (like snot) pulling inward but the lower layers are too warm to resist the pulling inward because you are still close to the bed.

Maybe get the fan up to speed sooner or lower the heated bed (and/or the nozzle) by another 5C.