Holes in the top layers: Replicator 2X

[Idefix]

Hi,

I have played around extensively with the settings to get proper prints on my 2X running sailfish printing ABS with a 0.2mm layer height but so far had no luck.
I used the following surface calibration model to play with the settings: http://www.thingiverse.com/thing:39050

None of the settings I tried so far resulted in a proper finish as I could get with Makerware or RepG.

I can either get:

1) a smooth base and pin but with pin holes in the top layer
or
2) a top layer without holes but blobs/drops around the pin

I tried to change:
- Multiplier (multiplier below 1.0 will increase the holes, above 1 will close the holes but introduce more and more blobs/drops around the pin)
- Nozzle size (both increasing or decreasing the nozzle size from standard 0.4 in the settings will lead to larger holes in the top surface)
- Auto extrusion width (switched it off and tested from 0.3 all the way to 0.5 in 0.03 increment steps - all prints with auto extrusion width off give a solid top surface layer, from 0.3 - 0.45 I get blobs/drops around the pin, above 0.45 I get holes in the pin itself).

These issues are also evident with other parts I tried to print.

Both Makerware and RepG do not have these issues and print the piece perfectly.

Attached is the Creator profile I'm using with the Rep2x as well as the pictures of the test prints - including one done with Makerware to show that this is not a printer issue.

Has anyone an idea what could be the problem?
I have no idea how the auto extrusion width parameter is defined but could it be that the slicer uses the wrong width when it comes to creating top layers, hence the spacing?

[Clayton]

Hey Idefix,

I happened to be near a Replicator 2, so I figured what better way to help you troubleshoot than to print this myself! I'm attaching the profile I used for the print. I started with the stock Replicator 2 profile that comes with Creator and then changed the layer height to 0.2mm to match what you were using. The stock retraction settings are extremely conservative, so I decreased the retraction distance to 1mm (you could probably go even lower if you wanted) and I increased the retraction speed to 2400 mm/min. I also manually set the extrusion width to a value just slightly below what Creator was using on the automatic setting to help get a nice clean top surface with everything fused together.

I like using clear PLA because it helps to highlight any potential surface imperfections. Sometimes you can even see imperfections that are a layer deep through the clear skin! The downside is that it can be a little difficult to photograph. The print turned out very well though. Very smooth round surfaces and a perfectly flat top.

I didn't see this mentioned, but what version of Creator are you using? It might be good to compare my posted FFF profile to what you were using to see what differences we had. Sometimes even the small things can cause big changes.

Replicator2_02mm_layer.fff

(3.32 KiB) Downloaded 788 times

[Idefix]

Hi Clayton,

thanks for the quick reply.
Could you post a picture of your sample print from the top please? The issue is with the top layer holes/gaps.
I would like to see how yours at the described setting compares to mine as default (as you could see from picture 1 in my post at default settings the sides and pin look ok but the top surface shows the gaps)

The printer I'm using is a 2X (Sailfish 7.5) hence I can not print PLA but ABS only (ran out of natural ABS through the testing hence the new ones are yellow, no change in filament diameter).
The Creator version I'm using is 1.1.4 (with the previous version I also had the top layer hole issue though)
I have tested the auto extrusion width default and its sets it for that piece to 0.63mm when applied.
Following your recommendation of retraction setting and auto extrusion setting just below 0.63 at 0.60mm I still get the blobs on the top and the holes in the base layer.

As I have played around with nozzle size, extrusion multiplier, extrusion width, relative and absolute GCode settings as well as various infill and infill overlap setting and not managed to get a proper print out of the SW.

Could you test it on a Rep2X please and post your settings?
Maybe it is an ABS issue (Filament packing density?)?

Thanks,
Eric

[Clayton]

Here's the same part from the top in ABS. Only change was using an extrusion multiplier of 1.0 and increasing the temperature to 220C.

I don't see any gaps in the top surface, and if anything, it's probably a hair too closely packed. You can see some slight ripples from too much overlap between adjacent lines of filament. If you print at 0.2mm layer heights a lot, you could continue to test different extrusion widths to find the perfect one for your setup.

From looking at your original pictures, the problem of gaps between adjacent lines of filament for the solid infill is really only due to 2 settings: extrusion width and extrusion multiplier. The nozzle diameter should be fixed for your machine and you don't need to change the relative/absolute gcode mode. You might also want to make sure you have a decent infill percentage (50% or greater). When you print at small layer heights you need a much higher infill percentage to ensure that the upper layers have something to build on top of!

[Idefix]

Thanks Clayton,

is the ABS print done on a Rep2x? If yes, what firmware version are you running?
I can only assume that the problem I'm having is Rep2x related or has something to do with the Sailfish 7.5 firmware.

I printed the 25th calibration model just now and it will simply not print it correctly. No matter the settings.
Any help you can give is highly appreciated.

br,
Eric

[Clayton]

Yup, and they were all printed using the stock MakerBot 7.2 firmware. Have you tried printing with the exact profile I posted earlier? If you are using ABS you would need to modify the temperatures and extrusion multiplier like I mentioned.

[Idefix]

Hi Clayton,

Not yet as I have to adjust them for the 2X.
I sued the standard 2X profiles that came with the 1.1.4 release.

I will adapt your profile and see how this goes.

Br,
Eric

[Idefix]

Hi Clayton,

the Rep2 profile you provided worked with the 2X right extruder and solved the issue for ABS (when switched to PLA I get the same issue again though).

But unfortunately I'm back to square one now on the usage of the left extruder due to the start gcode changes (initializes T0 only as it is fixed in the start gcode)
As you have a Rep2x, could you help post a fully working profile for the printer please? Also any plans to solve the extruder temperature issue?? (Currently I need to manually set the not used extruder temp point to 0C if I do not want it to heat up as well).

Thanks !!