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I’ve attached a couple pictures here. Can anyone give me a suggestion on the cause?

Is it most likely temperature? I’m obviously uncertain or I wouldn’t be asking.

2016-09-21 11.25.01.jpg
2016-09-21 11.25.01.jpg5312×2988 3.3 MB
2016-09-21 11.27.59.jpg
2016-09-21 11.27.59.jpg5312×2988 4.78 MB

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My first thought is level out of adjust. Maybe the nozzle is to close to the bed. I would start with the simple things like that. What temp is it set to extrude at? What is the filament? Machine type? What slicer?

Is the filament path free? Does the filament move smoothly?

One thing I do is get right down there with a hand held magnifying glass and try to watch the filament coming out and how close the nozzle looks to the bed.

Another thing is to maybe reset the software to a default settings to make sure something didn’t get out of whack.

If the simple things can get ruled out then on to partially clogged nozzle, extruder issue, filament issue etc.

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I think the level is fine. The big concern I have is that the filament you see being layed down is not uniform. As you can see in the second picture, in some cases it’s so thin as to almost be transparent, other immediately adjacent sections are what one would expect (perhaps even overly so).

The filament is some Hatchbox PLA, running at 215C on a 55C bed. The machine is a Qidi Makerbot dual knockoff. The slicer is Makerbot Desktop.

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I have the same machine. Temps seem fine.

My point on the level was this and it could be flawed logic! If the nozzle is to close (really thin areas) it could make the thin parts of the extrusion until pressure builds then it causes the bed to push down ever so slightly and extrudes more filament until pressure is off. The other consideration is the better extrusion could be low spots.

All I can say is I have seen a pattern like this and in my case the bed level was off. Just my thoughts.

Another thing maybe is first layer speed.

I Just noticed looking at the bottom left of the second print it looks like the nozzle dragged through the filament going from one hole to another.

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This is good advice. Looks like your too close to the build plate. Are you printing with a small layer height, like 100micron? If so, you usually want to set the first layer height to something larger like 200micron so you can have a little more room to get a solid/even first layer down. Once you get to 100 micron and below, what looks like a flat build plate, is actually not flat(unless precision ground). This is amplified with painters tape.
If it’s not the case that you are printing with the small layer height then you most likely need to calibrate the z axis a little higher.
-Jesse

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FYI, if you haven’t yet here is another group to join for QIDI.

http://3dprintboard.com/forum.php

Scroll down to the heading “specific 3d printer, scanners …” and pic the QIDI folder-area.

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Good point. I’ll check my first layer thickness, because yes it, is 100micron.

Only reason I’m using painters tape is because the adhesion has been so good I’ve had a hard time getting models off the bed, even if I crank up the temperature before trying.

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Nothing wrong with painters tape. Make the first layer 200micron and I think you will be all set.
-Jesse

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Awesome, thanks. I hadn’t had any luck finding a QIDI group.

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So, yeah, this may be a silly question, but what option is that in the Makerbot software? I can see where to change fan speeds and print speeds, but obviously that’s not it.

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Unfortunately, this I cannot help with. I build my own equipment, therefor most of my software is open source(I mostly use slic3r). Everything “makerbot” is proprietary so I have ZERO experience with it.
Sorry.

-Jesse

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The real question, is what does your second layer look like. First layers are the squish layer, and are often uneven. The second layer then fixes this.

All in all, your first layer does not look bad for .1mm. What does your second/third layer look like?

What does a print look like when finished. It looks to me like it would be fine and smooth on the bottom!

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I agree with what you are saying except that there are areas where is no material is being extruded. Squishing the first layer is one thing but if you are too close for anything to come out, then you are you are asking for trouble. Grinding filament, over heating motor/drivers, jamming/clogging the extruder, etc… One or all of these will happen.
He definitely needs to raise z offset or increase the first layer height.
-Jesse

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I agree with you, except there is no place where the filament is missing, looking closely. Just squished. For many printers, this is the only way to get a good .1mm layer.

People call this “baconing” because the first layer has a cooked bacon look to it. This is because it is almost impossible to get tape to sit perfectly level and flat and does not maintain a perfect thickness. There is nothing wrong with baconing if you want a smooth finish on the bottom or top (as some things are printed upside down).

I prefer it in many cases, and it is often recommended for folks printing on tape and having adhesion issues.

I also agree with you! - if there are places where it is missing on the first layer, then everything you said is true.