The first few layers of all my prints on my Printrbot Simple Metal look like this, with 3 different brands of filament. Is this overextrusion, temp, or something else? It’s inside and doesn’t show, but the hot end catches on it.
Could it be the z offset is too low?
Looks like over-extrusion to me
If it’s just the first few layers, I would recommend to slightly increase the distance between the nozzle and the bed in the first layer. See http://help.printrbot.com/Guide/3.+Setting+Up+Your+Auto-Leveling+Probe+and+Your+First+Print+-+Mac/107
looks like have you overlapped the tape too? i get that if i dont flush them up next to each other.
Your z offset is set to close to the bed. First layer should be squished but to the extent you have in this photo.
You look like you’re massively overextruding. Follow Richrap’s E-steps-per-mm guide, or just simply set your e-steps back to what they come as default on the printrbot model you have.
Also test angle between hot head and bed
I agree with the above. The ridges are caused by too much plastic trying to fill a space, causing it to squish up above the height of the nozzle. The nozzle being too low to the print bed. A single line of filament on the print bed, such as your ‘skirt’ should be an even bead of plastic, about half the width you’re seeing. I’d suggest first getting a single layer to print properly, using something like http://www.thingiverse.com/thing:215386 . You should be able to get it to look like this http://www.thingiverse.com/make:62762 . In particular, the lines should be even and solid, not so thin you can see through them, all the way around the print bed. The thing is Customizable, so you can generate one the size of your printer. This one is for the Printrbot Jr, which might work for you: http://www.thingiverse.com/thing:393265 .
Once the first layer is printing properly, your prints might be fine. But if they’re still messy like this, you can try a ‘calibration cube’, and use that to check that the slicer is configured with the right “steps per mm” for the extruder. If that number is too high, it’ll tell the extruder to push too much plastic, resulting in the mess you’re seeing. This article http://makerblock.com/2010/02/makerbot-skeinforge-tuning-and-calibration/ is quite good, though the instructions are for Skeinforge which you’re probably not using, so you’ll need to find the equivalent controls in your slicer.
The other problem I see is that the tape is overlapping, causing the print surface to be uneven. What you want is for the strips of tape to be next to each other, end-to-end, forming an even print surface. You can see that the raised areas are causing the bottom layer to be squished to almost nothing. This isn’t the cause of all of your problems, but it isn’t helping. And it’ll make the bottom of your prints have that line pattern indented into it.
Hope this help!
I turned down the temp from 210 to 190 before I read the comments here and it seems to have helped a bit (I had to restart that print because the hot end hit a bump and slipped over a few mm). I’ll try adjusting the Z offset and extrusion speed tomorrow. Thanks for the tape advice too!
Looking at this its both under and over extrusion, looks like your tension on your filament isn’t constant and your output is temperature led.
I suggest increase the tension on your filament.
@Nigel_Dickinson the “under extrusion” you’re seeing is just the nozzle being too close to the bed and causing the back pressure to build up and not allow plastic to flow because he overlapped tape layers. Pay attention to where it occurs in the photograph, and how it all happens on those overlaps.
@ThantiK not on the second layer, as on my simple and a totally flat bed I was getting the same effect, and filament not having the correct pressure leads to the same effect in the squish area.
Otherwise the tape would be indented or torn around the brim where there’s no output on the bed!
I’m using Cura, which has a steps per mm option, but it’s blank so it will use the firmware value. The default value is 94.5, so I reset it in the firmware. Printing the bed level test at 200 degrees, 0.2mm layer height now. I reapplied the tape so that it no longer overlaps. I also raised the z-offset from -0.5 to -0.4.
I printed a flat square, and the overextrusion seems to be only on the left half of the bed. I don’t think it’s level, but the G29 command should account for that, right?
Photo of just 1 layer. Notice the buildup on the left, but smooth plastic on the right. http://imgur.com/BiM9DvP
On the right side the ‘stringiness’ means that the print head is too far from the print bed. And while it’s blurry, I’d guess the left side is too close. So can you adjust the left side up and right side down?
I adjusted the z offset down .05mm, and the right side is no longer stringy. The left side is better now (surprisingly). Now I’m adjusting Cura settings to get it to work with flat objects better. Thanks for all the help!