Is it normal for raft-less prints to have this Tron-like texture?

I have a M3D Micro and lately have been having a hell of a time getting larger prints to print correctly. Without a raft they tend to lift, with a raft... I can't get the raft OFF even with X-Acto knives if it has a large surface area on the bottom. Even when printing with PLA, I tend to get lifting no matter how low or high I set my temperature.

Even when I do manage to get it to print without lifting without a raft though.... the bottom is hardly flat, and sometimes even missing areas that should be filled in. Does the bottom later of a raftless printout look like this to anyone else? Is it normal that it has all these thick lines on the bottom layer when raftless instead of looking smooth?

http://i.imgur.com/9OdHWdv.jpg

http://i.imgur.com/LHBYCkc.jpg

Hi,
When I look at the surface that was on the bed, you can see the individual strings.

It can be either of those things :
1/ you under extrude.
2/ your first layer height is not set correctly (too high -> not squished enough).

It is safe to rule out /1 because if it was under extrusion, you would see it on the rest of the print as well and it doesn't look to be that way.

So, you should check /2. I don't know the M3D firmware, but in reprap that would be a combination of M212, M500 and M501.

and the bed is probably not level.

With a printer without manual bed levelling - this could be a real sod.

The other thing - when printing without raft you need to oprint the first layer VERY slowly.

second set of pictures look absolutely fine.

What kind of finish were you expecting ?
The base of a printed object will reflect the surface it was printed on. As I understand it the micro uses a textured bed. So you'll get textured base to your prints.

Also, I noticed that when I turn off the raft, my prints have a few hollow areas around edges. This appears to be the software doing it on purpose, instead of an uneven or mis-calibrated bed, as it's always the same edge even if I move the location of the model on the print bed before printing, and I saw it purposely not fill in those areas when printing the first layer.

http://i.imgur.com/Q4vu7nb.jpg

Quote:

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Originally Posted by LambdaFF

Hi,
When I look at the surface that was on the bed, you can see the individual strings.

It can be either of those things :
1/ you under extrude.
2/ your first layer height is not set correctly (too high -> not squished enough).

It is safe to rule out /1 because if it was under extrusion, you would see it on the rest of the print as well and it doesn't look to be that way.

So, you should check /2. I don't know the M3D firmware, but in reprap that would be a combination of M212, M500 and M501.

---

Sadly, I don't have some fine-tine settings in my firmware. I can manually send it g-code, but I can't define such settings in g-code before sending it a print job, unless I print the entire job from a gcode file.

Quote:

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Originally Posted by curious aardvark

and the bed is probably not level.

With a printer without manual bed levelling - this could be a real sod.

The other thing - when printing without raft you need to oprint the first layer VERY slowly.

second set of pictures look absolutely fine.

What kind of finish were you expecting ?
The base of a printed object will reflect the surface it was printed on. As I understand it the micro uses a textured bed. So you'll get textured base to your prints.

---

I was expecting the bottom layer to look like the model that was printed vertically or on a raft, small thin lines that almost look solid, rather than the thick doodle-like lines. Do all printers print the bottom layer like that if you use no raft? This is my first one so I wouldn't know how others behave.

And I doubt it's the bed. Judging by that image I linked, the software seems to be doing it on purpose.

It's pointless to print this thing on a raft though, since the raft sticks ridiculously tightly to the printout. I just tried, and I could not get it to come off even with razor blades... and it was even less flat than the non-raft model, as the plastic appears to have filled in the cracks in the raft in very fine lines. This only seems to happen with models that have a large flat area against the bed, models with a smaller footprint don't really seem to have trouble coming off the raft.