bad prints

[maxehg]

The side is the same but I will try using other types of infill

[curious aardvark]

the only infill s3d offers is rectilinear - useles if you need strong parts as it only prints alternate layers. so you don't get rigid infill.
And spiral infill - which is interesting, but again not massively strong.

But I've never had any issues with surface finish - certainly never looked that bad. I'd go with maybe some crap in the nozzle or too low printing temp.

Also - every roll of pla has it's own characteristics. Different colours print at different temps. I've got 2 rolls of white pla. One prints at 220c and won't even extrude below 210 and the other prints at 210. One is reprapper tech ltd (220) and the other (210) is just the cheapest pla i could find on ebay.
The cheap stuff (£5 a kg cheaper) warps slightly more than the reprapper, but other than that is excellent.
But both print hotter than other colour pla I've used.

I think you're printing temps are too low and the pla is too thick to layer properly. Get it hotter and runnier and you should find the issues go away.

[maxehg]

Hello
I dont think it is the nozzle because I can get good prints with black PLA.
My last print was a failure, I tried printing at 220c and got this:
20141228_201800.jpg
The one before this one was also printed at 220c and was a lot better so I dont understand what happened.
I am also having trouble leveling the print bed and do not understand how the number of shells, feedrate and travel feedrate affect the quality of a print , any tips/advice?

[jfkansas]

You can setup S3D to do several different processes depending on layer height. I usually don't but if it was something special that I was making a bunch of I would consider it. I have one piece that has a "roof" 1mm from the bottom that I have troubles keeping smooth. A true roof that is the top couple of layers is handled a little different. It is thin enough that I set the number of "floor" layers to 5 .2mm layers so it doesn't try to do some infill. I have considered making a special profile that would treat the 1mm high flat bottom as a roof, then start printing the rest of the sides that go up. I just haven't taken the time to do it. S3d handles it like this, for each process you can set a start and stop layer. So in my case I would do a start at layer 1 and stop at layer 5, this would make a roof which is actually at the bottom of the piece. Then the second process would start at layer6 and go to whatever the last layer would be.

[jfkansas]

Hello
I dont think it is the nozzle because I can get good prints with black PLA.
My last print was a failure, I tried printing at 220c and got this:
20141228_201800.jpg
The one before this one was also printed at 220c and was a lot better so I dont understand what happened.
I am also having trouble leveling the print bed and do not understand how the number of shells, feedrate and travel feedrate affect the quality of a print , any tips/advice?

looks knarly, ABS is better at 235-240. Also make sure you run the build plate around 90, and enclose the printer sides. Dump the Krapton and use borosilcate (pyrex). My go to sticky stuff lately has been a liberal coat of glue stick. Also make sure you calibrate your extrusion volume, this comes before everything else.

[maxehg]

I am currently printing using PLA.
How do you calibrate your extrusion volume?
Thanks, I will check S3D

[maxehg]

I no longer have trouble with grainy surfaces but now I have a problem when I print cilindrical objects.
I tried to print this:

rings_preview_featured.jpg

and got this:

20141230_013357.jpg

Can someone explain what is happening and how to fix it?
I thought it was a problem with the bands and tightened them but it didnt help.

[jfkansas]

Looks like you might have some pulleys slipping on shafts. Layers look good, just looks like the x or y axis is shifting positions a little.

[curious aardvark]

yeah. what he said.

As far as extrusion rates and the like - I've never messed with them. And never needed to.

Shells can make hollow or sparese infilled objects stronger. I pretty much use 2 all round for most things. For hollow models I might go to three. And if I want something strong and I'm using s3d I might even go to 4.

Also when you adjust printing temps - do so in small increments.
Jumping from 180 (think it was around there) to 220 is kind of one extreme to the other.
Go up in 5c increments with a small complex print and stick with the print that looks best.

This is my test object:
holecube.stl

Basically a cube with a sphere removed. If you can print a fairly clean version of this - then you're good to go on pretty much anything else.
Plus it only uses about 1 gm of plastic :-)

test-spherecube-thing.jpg

The middle section is particularly difficult, great test for extrusion temps.
If you can knock one out at 0.3mm then you've got a really well calibrated and setup machine. I usually print it at 0.2mm.
It also tests everything else from under hangs, over hangs, bridging, precision of placement, retraction (amount of stringing) and anything else you care to think of.

IT's useful to have a benchmark file that you know what it should look like. That way when you try new settings or filament you can knock one out and adjust till it looks right.

Bear in mid that 3d printing - as we currently do it at home - is still as much an art as it is a science.
And we're all operating our machines at different temps, humidity levels and altitudes (air pressure effects expansion rate of hot materials). So what works for me - might not necessarily work for you and vice versa.

The only things I regularly mess with are extrusiuon temps, layer height, shells and print speeds. And i can pretty much print what I like how I want it.
You can change too many things and then not know which change made the crucial difference.

And from experience. The two most crucial things are extrusion temp and a really really level bed.

[catalyst]

Do you have any example images to show how your prints are coming out when properly calibrated?

Are you printing it with or without supports and should it be the same with both PLA and ABS?