Print Quality issues with my first printer

Hi,
I just assembled my first 3d printer.
It´s a Prusa i3 with 3mm filament and a E3D V5 hotend with a 0,4mm nozzle.
I already calibrated the axis and the extruder.

Unfortunately my prints look weird:
There are blobs on the surface and and bridging doesn´t work at all.
The part in the first picture should be closed on top.
The ends of the walls look weird, too.

The material is ABS and the nozzle temperature 235°C, bed temp 85°C.
Layer height is 0,2mm.

Could you please give me a direction what could be wrong?
Oh, I used Cura for the prints...

Thanks
daishi

Hello dashi!

Could you please frove a picture/link of the model you are trying to print, so we can see what it is supposed to look like?

My suggestion would be this:

You say you have calibrated the axis and the extruder. Measure your printed parts and check that the dimentions in all axis are correct. I recently had some trouble with my Prusa i3 where the z-axis speed was too high and it couldn't rais quickly enough. I don't really think that is your problem, but it is always good to eliminate variables.
The printing process is also very sensitive to the rate at which the plastic cools. If your printer is somewhere the ambient temperature might change quickly, (drafts, heaters, doors, windows etc), consider moving it, or make sure the temperature stays constant. Make sure your software/firmware is configured correctly. Pay particulary attention to the thermistor setting in the firmware, and make sure you are using the correct one. Did you buy the printer as a set, or have you gathered individual parts? What kind of electronics are you using? (Arduino with RAPS 1.4?) Did you download and install firmware yourself, or did the board come pre-loaded? What kind of firmware do you use?
Try printing smething simpler, for example a 15 mm cube and see how it turns out.

I realize this isn't very direct advice, but if you get back to us with some more information I am sure we can help you.

Have a nice day!

Hi Woodwalker,
thanks for your help.

Here is a picture of how the part should look like, although it is upside down in the picture, I tried to print it with the opening to the bottom...



I bought the printer as a kit, it has the Sanguinololu 1.3a board and runs with Marlin.
The firmware came preflashed but I reflashed it when I calibrated the extruder and the Z-axis.

So you think it could be a temperature issue?

Thanks
daishi

I am not a hundre percent sure what the issue is, to be honest.

First of all, I think it makes a lot more sense to print it the way you have it on the picture, to minimize the bridging. No reason to make it harder than it needs to be.
So, the large straight section of your second picture looks great. The problems seem to occur around edges, bridges and corners. The blobs near the bend in the part in picture 2 and top right in picture 1 seems to me like they could be caused to oozing when the the extruder goes from one layer to the next. The misformation on the end of the part on picture 1 is a bit hard to nail down, but it does not seem like the layers are sticking together too well at that point. The wall also seems a little bit wavy near the edge. Can you confirm this, or is it just the light? All these problems could be temperature related, but they might not be.

The third picture I imagine is a sphere, a separate part? Is it hollow, or did you print it filled/partially filled?

As I said, I am not quite sure what the problem is. As I mentioned, it might be temperature relate, but I would not hope it would be this sensitive. But on the other hand the transision from liquid to solid is quite fast, so maybe... I would suggest trying to lower the hotend temperature by say 5 degrees and see if that has any effect. It is my best advice, but not too helpful I am afraid...

I'll have a look around and see if I can find something more helpful.

Good luck in the mean time.

Hi again,

the end of the sidewall indeed seems to be a little weavy at the end and then there is a blob when the nozzle changes direction.
Unfortunately I am still at work, I could make a better picture once I am back home.

The third picture is the top half of a sphere and the top fails to close. There are also "bubbles" on the side where the layers start/end.
I printed it with 0,2mm layer height and 20% filled in a crosshatch pattern.

I will print a fully filled 15x15x15 test cube when I am back home.

Thank you so much!

Here is a better picture from the deformed wall:


...printing some 15mm cubes with different temperatures now...

Hi again,

I made some really good progress yesterday: I changed from Cura zu Slic3r and the calibration cubes look great:


They are printed with 0.3mm layer height but still look more detailed than the 0.2mm from Cura.

Only the bridging on top of the complicated part didn´t fully work. The first layer of the bridge was only partial, so there is a mess on the inner side of the part:


Maybe I need to change the bridge speed or the flow multiplier? Right now I am at 150mm/s and 1 respectively.

Have a nice day!

Sweet!
I am happy you are making progress. For your bridging issue, the easiest solution by far would be to print the part upside-down, i.e. start with the roof. Then the rest of your bridged parts and overhangs would be a lot smaller, and you could even use support for the rounded bend near the roof (currently bridged area). It might also give a smoother surface for your notch area that is also currently a rather sharp overhang.

But hey, what is the fun in shurking challenges? If you want to use the current configuration, I would suggest playing with the speed. Not sure whether to turn it up or down, as I have limited experience with this kind of bridging, but I'm sure you'll figure it out. I would reccommend creating a test part with just the bridging, so you don't need to print the whole thing over and over.

Let me know if you require any further assistance.

Enjoy printing!

Thanks .
Yep, I think, I am making good progress .
Generally the print quality is good now, I even managed to print the bridge.
Now the only problem I have is that bigger parts split because of warping
of the ABS:


I have read, that some people put a garbage bag over the printer
to keep the heat in and that solves this issue?

Thanks