Very first 3D prints, but bad quality. What can I do?

Question

To start with, as stated in the title, I am very new to 3D printing.

We're a toy/boardgame shop and we're experimenting with 3D printing because it could open up a huge market for us. To this end, I'm asked to try to get this off the ground, but also for me it's a big experiment.

General Information

Printer: Craftbot Plus
Slicer: CraftwarePro (1.1.4.368)
Filament: PLA - 1.75 mm
Designed in: Tinkercad

Problem

I designed a puzzle box in Tinkercad. Here are some images of the design:

I've printed it twice, but both have some problems. I made some pictures, hopefully showing the flaws clearly.

Print 1

This print actually came out pretty ok, but not the quality I'm looking for.

Print 2

For some reason, this one came out way worse in my opinion. I didn't change any settings. The reason why I made this second print is that there are some design flaws in the first print.

As you might be able to tell, this one has some more severe problems, like the prolapse on one of the corners of the lid and some threads that just seem to be broken off here and there.

Question

My question is basically, what is likely to be the problem, and how should I solve them. Are there some settings on the printer, or in the slicer that needs to be changed? Or could it be something with the design, for example, would it be better to have the lids laying down on the bed, instead of standing up as I have them in the design right now?

Also, here and there seem to be threads of plastic where I think there should not be any.

What have I found myself

Since I'm very new to this, I wasn't really sure what to search/look for. I know it's expected to do some research yourself before posting any question, but I really didn't have a clue where to start.

Though, while typing in the question, 2 suggestions showed up:

Suggestion 1

I have bad print quality, what should I do?

I'm not sure this looks like any of my problem areas, but somewhat similar.

Suggestion 2

Bad quality at horizontal faces

This looks very much similar to how some of my areas look. Is the problem described in this post indeed the same as mine, based on the pictures?

Conclusion

In both posts, "Under Extrusion" is mentioned this is probably something to look into?

Some personal observations

There are 2 things I noticed myself, maybe some conclusions can be made from this:

1. Something else I'm noticing while heating up the extruder is that plastic already leaks out in a very thin thread before it actually starts printing.

2. When the print is done, I notice thin threads of plastic between the different objects (Like a spiderweb), this probably has something to do with point 1.

3. When the printer is starting, I notice that the very first threads of plastic are not a fluent string, but sometimes get interrupted, as if no plastic is coming out of the extruder for a short moment.

Conclusion

Hopefully, I provided every information that is required to answer this question properly. I'm looking forward to any offered assistance.

In case any additional information is required, I'm happy to give this next time I'm at the office.

P.S. I had to remove 6 links (pictures) to get to my maximum of 8

Answer 1

There are several issue at hand here, first you have an adhesion problem.

This print shows that the print (as it is printed upright) has come loose during printing and lifted up. Such a print should have been printed as it is now laying on your table. You will then also get far better quality of printed holes. So, second is print orientation on the build plate.

This shows another example of adhesion problems, but it also shows that you initial distance between the nozzle and the bed is slightly too large. The paper method usually works fine, but you can use feeler gauges. Alternatively use a specific 3D print adhesion spray (3DLAC, Magigoo, DimaFix) or alternatively some hairsprays or glue sticks.

Third, design. Just a tip, I see that your design uses some sort of a pin:

you should avoid thin pole/spike like prints. These are difficult to print and usually very weak. Think of an alternative, an embedded shaft or a bolt is usually a much better solution.

Fourth, this shows that there was no filament printed, it could be that the spool had extra resistance or the filament was entangled. Check your filament spool.

Fifth, this shows that you have a retraction problem, the filament pressure is still too large when the head moves to the next coordinates, it then oozes until the pressure has been released. Changing retraction speed or distance may help.

Answer 2

Adhesion

Try raising your bed temperature a couple of degrees at a time. Presumably your filament has some "suggested temperatures" on the spool, but they sometimes only give a hotend's temp. For PLA some people get good results with a 50 degree C bed, I find nothing less than 60 degrees C. Esun's rec seems to be 60-80 for the bed.

For the hotend my esun PLA+ suggests 205-225 and I print at 218.

Depending on the environment, draughts can upset things and trigger lifting. If the printer is in a place where there are winds/breezes, or airconditioning that cycles on and off, the temperature fluctuations can start lifting. Try putting your printer somewhere that there is no wind and air conditions are static. I have a curtain around mine, and some people use enclosures made from popup laundry baskets or similar. Doesn't have to be fancy.

You can try things with light layers of water-soluble gluestick on the bed, which works for me. Others have had success in laying blue painter's tape on the bed but I found the heat made the adhesive a hot mess.

Orientation

That pin will never work - 3D printing has layers and items are always weak along the layers. So that part is a poor candidate for 3D printing.

Instead, buy a large assortment box of M3 nuts and bolts. These work much better than thin printed parts.

Also, that large lid should be printed laying flat on its back. Even the action of the bed moving around could be creating enough breeze to cool that part quickly and cause shrinkage.

Design

That dovetail at the foot of the box, as printed it will have a layer line right across the base. Since that looks like the most economical way to print this part, you might consider making the dovetail a lot wider, and it may need a slight draught angle added to help the lid engage smoothly.

The lid might spin around the pin and whack the dovetail clean off too - perhaps the two sidewalls should be raised so the lid only slides off in one direction?

Lack of filament

Holes in a printed part are a kind of under-extrusion, and mean there's not enough plastic at that time. If your roll of filament is under friction then the printer may not be able to pull it in fast enough.

Also if the hotend isn't hot enough it may not be melting quick enough for your print speed, or there may be clogs in the nozzle from contaminations in the filament.

Suggestion

Start by levelling the bed, and then print one item in your set. Use a "brim" to improve adhesion, and it will be done first. As your printer starts the job, watch it closely and manually adjust the bed on the fly.

Imagine these as side-views:

____ _{__} _____ Nozzle is way too low, you're scratching the bed
____ __ ____ Nozzle is too low, so drop the bed down a bit. The filament should have colour.
____ ^__ ____ This is about right.
____ o _____ Nozzle is a bit too high
____ O _____ Nozzle is a lot too high
____ ^O _____ Filament is floating in the air which is sub-optimal

Ideally you want to feel the printed filament line as a flattened line stuck to the bed, and not a round string lying on the print bed. It should almost feel like the edges of a sticker.

Of course, the printer is moving all the time. Do not get in its way, and if you do block the motion in any direction then the print will likely be ruined.