Print doesen't have an even surface

[joakimjay]

Hey so I just spent like 30 hours on a really big print sliced into 2 different prints. But the bottom surface of the top part came out uneven, which means i can't put them together.... Printing with high temperature PLA

Here's some pics.

What can this be?... Here's the profile used aswell on my Flashforge Finder.

FlashForge Finder.fff

(15.04 KiB) Downloaded 412 times

Could it be a simple calibration of the bed? Or maybe the first layer settings? help me out please... thanks

[gwhite]

You don't say what your material is, but this looks like a classic case of "warping". It's very common with large parts. PLA is definitely prone to this, but it can be a problem with most materials.

Check out the warping section of the S3D trouble shooting guide:

https://www.simplify3d.com/support/prin ... g/#warping

[joakimjay]

Sorry, yeah its "high temperature PLA"

[gwhite]

That is probably pretty "warpy". It's really an issue of shrinkage due to temperature changes, so the hotter you extrude at, the more it's going to want to shrink. A heated bed helps, running the extruder at as low a temperature as possible helps. An exclosure (heated if possible) also helps. Basically anything you can do to keep the print warm until you are done is a good thing. Beyond that, you are stuck with trying to keep it firmly attached to the bed until you are done. That's where rafts & brims come into play.

[MasterFX]

Stock flash forge finder seems not to have a heated bed. What is you build platform? Glass+Gluestick? Buildtak?

[joakimjay]

There's no heated bed, I'm just using some blue painters tape on top of the bed, that's it... any suggestions? I'm going to try raft/brim.. but it feels like it won't be enough, also I lowered temp to 190 degrees.

[smarcus3]

I had this issue when printing large electronics enclosures.

A raft fixes all these problems. For all the naysayers on rafts, they are used on all professional FDM printers which cost $50-100K. If these were fixes for bad printers / setups clearly the big dogs in the market would have fixed and eliminated these.

My settings for PLA are

.2 layer height with .4 nozzle
205 Extruder temp
60 bed temp for layer 1. 50 for rest of print. I believe it would work fine with no heat.
3 dense layers on the raft top.
.37 raft seperation
3mm raft inflation.

[dkightley]

The changes to rafts in v4 have made them much, much better....and a darn site better to remove!!

I print PLA and use 1 top layer, 1 base layer, and 0.05 separation distance with a 50% top infill. This is for both 0.2 and 0.4 nozzles and 0.05 to 0.2 layers.

[smarcus3]

The changes to rafts in v4 have made them much, much better....and a darn site better to remove!!

I print PLA and use 1 top layer, 1 base layer, and 0.05 separation distance with a 50% top infill. This is for both 0.2 and 0.4 nozzles and 0.05 to 0.2 layers.

with PETG I use .14mm seperation distance. With PLA I had to increase to .35 otherwise the part would fuse to the raft.