New A8 Owner

[Thurston]

Hey everyone,

I’m a brand new A8 owner and so far I’m loving it. It hasn’t been perfect but building the printer myself has helped the troubleshooting process through my first few failures. I was able to fix the problems I first had but now that it’s generally working properly there are quality issues that aren’t so obvious to me.

For a quick rundown, here were my first problems:

1. Nozzle too far so the print didn’t adhere to bed: easy fix to recalibrate distance

2. Z-axis binded and so it kept extruding at the same level: discovered the “proper” way to install the z screws and couplings at motors. Runs smoothly now with no binding.

3. Major shifting along x-axis: when I was trying to fix #2 I ended up messing with the bars the extruder runs on and ended up loosening the belt. Tightened belt and it’s good now.

After those 3 major issues the printer is finishing prints without any problem but my end results aren’t the greatest. I’ve included some pics below and some ideas of what I “think” might be happening but want to see what you all think before I go haphazardly adjusting things.

I’m running:

Cura 3.1

Anet A8 with no changes to config at printer

Sample PLA that came with the printer (small amount limits my ability to print lots of examples and make minor tweaks. A new spool arrives Wednesday.)

This is the A8 Filament Guide made by papinist. Obviously there is no issue with the design itself since it’s the most popular one on Thingiverse but my printing need some help. As you can see in the pictures there are some holes and gaps here and there. Also, it generally seems to be wavy and bumpy on the circular part. Based on my internet research and the Anet troubleshooting guide I’m leaning toward one of the following:

1. Extruder temp too low

2. Too little extrusion

3. For the wavy/bumpy circle perhaps vibration?

Print specs:

Resolution .2

190 C (lowered to 190 due to bulging corners on a cube I printed at 200)

60 C bed

45 mm/s speed

90% flow (I lowered this because my first successful print seemed over-extruded)

15% fill based on papinist’s recommendation

Top/bottom layers 0.8 w/ 2 layers

Also, unrelated to this print specifically. when I dowload an stl and open it in cura, do all the print settings carry over from the file or are they independent and tied to my own settings in cura? i.e. When someone designs an item do they set the appropriate speed/infill/wall thickness etc. or is that all on me as the printer?

Thanks for any help! I can tell I’m going to love this hobby but it’s definitely not plug-and -play…at least not with an A8.

Thanks,

Ken

[Lea3DPrint]

Hi,

You’re using a fairly coarse resolution at 0.2mm layer height, but it mostly looks like over extrusion.

The photos are quite small, so it’s hard to see too much detail.

Also filament has a lot to play in this, so a new reel may achieve better results.

In response to the Cura question, the Cura settings are remembered and applied to the next print.

The STL file is only the model itself; no printer settings are included.

You might want to print a test cube and fiddle with temperature and extruder flow rates to get the best results.

[Thurston]

Thanks for the tips! The photos were larger but when I moved them from my phone but they shrunk quite a bit.

I got got my new PLA yesterday and ran the test box off the SD card. I’m pretty happy with the results but as I watched it I definitely saw that there is vibration/stuttering along the y axis. It’s not major and it didn’t shift the print but it did cause a lot of waviness in the layers. There was a clearly visible difference between parallel and perpendicular layers with respect to y. After much web searching I think maybe the bearing are just getting hung up a bit or the rods need to be cleaned and lubed.

I didnt take take pictures of the box but will when I get home tonight. There are a few spots where there are divots and gaps but they don’t go through the wall.

Thanks again!

[Thurston]

After getting a couple really messy prints this evening I decided to dismantle and reassemble my beat bed and H-carriage. I tried my best to screw the H-carriage to the bearings without causing binding and it seems to have been at least somewhat successful.

Here’s a 20mm cube after I put it all back together. The filament along the y axis is MUCH smoother than it was but there is still vibration. The worst corner is where it was changing layers.

What I’m not sure about is the back corner where there are a lot of gaps. Could this be a mechanical issue caused by a certain directional change? It only did that on that one corner.

Temp and extrusion looks okay…but I’ve owned a 3D printer for a week so I don’t know much.

Thanks!

[Lea3DPrint]

How many perimeters are your walls? You should have at least two.

If not, it’s looks like a little under extruded.

Your shifting layers are due to loose X,Y carriage belts or Z wobble.

I’ve reduced this significantly on my printer by moving to PTFE bearings.

The linear linear bearings have a lot of slop.

Otherwise, it’s not too bad a print - just needs a little tuning!

[Thurston]

Thanks again.

Since that cube has the flaws just on one plane of one corner could it be that it’s binding or vibrating in one spot? If it was an extension issue wouldn’t I see it all over, or maybe it was performing a specific extrude/retract action at that corner?

What symptoms might I expect if my belts are too tight instead of too loose?

could an uneven bed cause that sort of error?