Wavy quality issue.

[JohnnyRobot]

Hey all,

I'm getting a weird quality issue and I'm not sure what's causing it.

When printing, during infill on larger parts, I get this strange wavy effect. Looking at it, it seems like the material is not coming out of the hot end uniformly, almost as if there are surges of material.

I experience this issue with both ABS and PLA.

Has anyone else experienced this? Any ideas?

[Toby]

Can you post a picture showing what you mean?

[JohnnyRobot]

Dang autofocus doesn't work that well for a moving target.

To the left you can see how it looks right out of the the nozzle.

Bed is level, and at what I think to be a good height. (A sheet of paper)



And here is what the top finish looks like. It's very rough. Feels like sandpaper.

[Toby]

I haven't seen that one before. Only thing I can think of is there might be some slight obstruction in the nozzle tip. It doesn't take much to make the filament come out distorted. Maybe try extruding manually for 10 mm at a time to see what it does and/or wipe the tip down with alchohol

[JohnnyRobot]

That's what I thought at first. I've got a brand new nozzle and tip.

It did it with the old nozzle too.

[Toby]

What slicer are you using? Does the gcode preview look normal?

The thing that seems odd is how regular it looks. Normally if it's a printing failure it's just going to be a mess. I'm thinking if the extruder gear is being driven off in some regular way it could cause this. Back up the mechanical chain and maybe the problem can be located.

[JohnnyRobot]

More research is leading me to believe it's moisture absorbed in the ABS.

[JohnnyRobot]

I found this.

Hey guys,

I have some serious moisture issues with a few of my MBI ABS spools. There's way too much moisture in them and I can see the filament balloon out when it exits the nozzle from the steam. I hear that you can help reduce the moisture content by baking it however, I can't find any specifics. Can anyone help me locate some instructions?

Also, this means I need a much better storage solution for my filament. Any suggestions for a storage container? Or where I can buy desiccant in bulk?

Thanks!

https://groups.google.com/forum/#!topic ... wuSEecmfGs

[j-rod]

Mine will do that but only on the first layer and only in certain spots, so I always figured it was due to not having the bed perfectly clean and there being different levels of adhesion happening.

[jimc]

well in the fuzzy first pic, those waves you have showing on the right, in the middle of the model, those are from the first layer printing too close to the bed. the edge being jagged could very well be from a combination of the 2. too close to the bed and damp filament. i am guessing on the edge one.