thin wall printing z Seam issues

[Alan555]

New user of S3D. I have been tweaking settings in a print I am testing - a part from a 3D model aircraft from 3dlabprint.com.

Their settings are print ready but require tweaking for different makes of printer. I have my CR-10S printing almost perfectly but when the printer is printing the perimeter (a single 0.45 skin) every time it stops on a completed layer and then jumps to do internal print it leaves a visible seam.

Previously I printed the same part using Cura 3.1 and there were no visible seams. One of the main reasons I bought S3D was that the models have specific factory files for S3D making it easier to get accurate prints with the correct weight and dimensions. Hopefully some of you expert users can suggest which settings can be changed to help with this?

[horst.w]

Hi,
I know the models of 3dlabprint.com are under copyright and it is not allowed to show a factory file of it.

But to see if some settings may be improvable its the best to know the factory.
You can do all your settings with the model and than remove it to store and attache the empty factory. All settings will be transfered.

Use SEARCH, there are some threads in the forum concerning problems with models of 3dlabprint.com

Without knowing your complete settings I would say the problem is mainly to locate here:
https://www.simplify3d.com/support/prin ... s-and-zits, specially the paragraph "Non-Stationary Retractions".

Regrds
horst.w
GER

[webdad]

I have this exact same issue. Thin wall is enabled, and there is a distinctive seam on the corner where I believe the layer starts and ends.

There is also an identical seam on the inside of the box.

http://cubeupload.com/im/webdad/20180116205556.jpg

My settings had "Wipe" enabled and "Perform Retraction during wipe movement" enabled. The only difference was my Wipe distance was 2.0mm so I bumped it to 5.0mm.

Will try this setting and see if that helps.

[horst.w]

Yes, the seam is horrible and I have never such an issue.
Maybe you have an overextrusion or the settings of Retract / Restart / Lift included Print Inside / Outside and StartPoints are bad.
Please also attache your factory file for this print here if you want somebody can help efficiently.

H.

[webdad]

Yes, the seam is horrible and I have never such an issue.
Maybe you have an overextrusion or the settings of Retract / Restart / Lift included Print Inside / Outside and StartPoints are bad.
Please also attache your factory file for this print here if you want somebody can help efficiently.

H.

Thanks. I tried the 5mm wipe distance, and there wasn't any significant improvement, actually might have gotten a little worse. I've been using these settings in general. I've attached my profile. I've been using the PLA filament setting.

My printer is a D-Bot (coreXY) printer that I built. Tiitan / E3D V6 full / Bowden set up. Bowden tube is about 700mm, and using Capricorn tubing.

I've been through calibration of the steppers and the extruder. Fairly happy with the prints except for this seam issue.

Any guidance you could provide would be greatly appreciated.

[horst.w]

Hi,

I have nearly the same machine - conditions with my Mankti, 70 cm Bowden, E3D V6 Full Metal a.s.o.

Following your FFF file, I would propose to try settings changings:

Tab Extruder
- Retraction - Restart Distance >>> -0,15 mm (negativ value!)
- Retraction Speed, I have set only 25 mm/s. With higher speed I have no good experiences, the detachment between nozzle and last layer (just being liquide) is too abrupt and material builds a nobble (see Cooling)
- Multiplier 1,05 seams a lot to high for PLA but that is to be tested out, when the filament diameter (Tab Others) is messured very exactly with a micrometer screw; I'm using mostly +/- 0,95 for PLA and derivates.

Tab Layer
- Start Points >>> set the 1st option, use Random Starts

Tab Temperatures
- try to reduce the extruder temperature. PLA needs normally 190° + , I'm printing it with 195 °, the derivate from GreenTec is offered with 170 - 220°, it is running very well with 180° (by glass point 120° !) Max 60 mm/s speed don't need it too.
The best is to try it out by hand, heat up and open the pulley of the extruder, push the filament through by hand without tools. Than stop pushing and heating, the temperature is ok when it is coming out for 1 - 5 cm by gravity /rest pressure

Tab Cooling
There is no doubt about it, PL needs relative strong cooling. The problem is always the fan and the air-mouth. If the airmouth is blowing directly on the nozzle, perhaps from only one side, than the cooling is contraproductive with 100%. The extruded, molten filament needs some time to be smoothed and the nozzle must able to be mouved without riping the surface.

Tab Gcode
I have no experiences with the relative extruding distances but this may be not relevant to the problem.

Please try out my suggestions step by step to observe the reactions and begin with the temperatures.

H.

[Alan555]

For the start points I have had good prints with setting the start point in the Layers tab to "Choose start point cloest to specific location and X200 Y100. Have not tried with any other parts yet but on the fuselage parts of my Stearman the seam is now on the bottom.

[webdad]

Thanks! I'll start working through these suggestions.

[Alan555]

Just one observation. PLA does need cooling but the situation is different on the 3D Lab planes. They are designed to be as printed single thin wall with the parts fan switched off. This ensures better bonding of the layers in the thin wall and good strength to weight ratio.

[webdad]

Horst,

THANK YOU for those settings. They did improve the seam significantly and it is pretty much gone.

I went with these settings:

Restart: -0.15
Retraction Speed: 25
Start point: Random
Cooling: 50%

The only thing I have outstanding is a small bulge or "seam" on one corner. All the other corners are perfect.

I've tried lowering the temp to 200 and that improved it a bit, and made it less rough, but it is still there.

I tried reducing extrusion from 1.05 to 1.03 but that didn't have a noticeable affect.

Watching it, it definitely occurs as the layers are changing.

I'm thinking that I'll try increasing the restart to -0.2 or so to see if that helps.

Thanks again. If you have any other recommendations happy to hear them.