PLA adeshion  

Re: PLA adeshion

Did you try using the included glue? This helps for adhesion, and I think especially on smaller objects you need it to get it to stick.

Re: PLA adeshion

What firmware version? What method of first layer calibration?

If you fine adjust Z too low, first layer gets too squished and tends to not stick to bed.
If your firmware limits minimum Z to 0.2mm while your slicer is set up to first layer height of 0.15mm, you'll get underextrusion in first layer.

Get some simple object (cube) around 30x30mm (height is not important) and slice it with slicer set to first layer height of 0.2mm. Begin print and fine adjust first layer to get equally covered area with no gaps, bumps or dents. Then reslice Marlin with the same settings and try to print it.

Of course, the bed must be perfect clean and degrased. Continue using pure IPA for cleaning.

Re: PLA adeshion

And how fast do you print? When I print small objects like that I take down the first layer to 30% or so, and make sure that its really squeezing out the filament onto the buildplate. After the first layer is done I raise the nozzle just a little again.

Re: PLA adeshion

The print is the "PLA Marvin" downloaded with other demo prints, so I assume that it's not an issue with speed, fan or low bed heating, since I expect all to be OK in the gcode (for MK2 and PLA)

Other info:
- The firmware is 3.0.6 (so the last one)
- The calibration is the calibration process for MK2

I'm assuming glue is not necessary, since the print is very small

Re: PLA adeshion

The print is the "PLA Marvin" downloaded with other demo prints, so I assume that it's not an issue with speed, fan or low bed heating, since I expect all to be OK in the gcode (for MK2 and PLA)

Other info:
- The firmware is 3.0.6 (so the last one)
- The calibration is the calibration process for MK2

I'm assuming glue is not necessary, since the print is very small

Well lower speed = greater chance of success, so I would turn the speed down 30-50% for your first layer printing that Marvin. You can bump it up to 100% when you see that it has got a good start!
And use the glue stick as said, when you have small areas that needs to stick to the build plate, extra glue could be needed.

Re: PLA adeshion

3.0.6 brought back the bug of minimum Z, which is 0.2mm again. But demo print Marvin is sliced to 0.12mm first layer, so you get underextrusion in first layer, because the nozzle is actually 60% higher than assumed in gcode. In next layer, which is (according to gcode) at 0.22mm, gcode assumes 0.1mm layer height, but the nozzle actually rises only by 0.02mm, so you get massive overextrusion.
Reslice it using 0.2mm first layer height.

Re: PLA adeshion

I found that on my MK2 I have to set the bed temp to 70°C for the first layer, then the default for the rest, to get a nice solid adhesion. Also make sure you haven't got your nozzle to high as that can make adhesion worse. I've not had a dud print since setting using the 70°C setting though! Good luck!

Re: PLA adeshion

Yes agree with 3delight. Need to keep the heat on it. I noticed the front would lift before I built my enclosure due to a draft. Walking by it would cool it too quick.
The fan also plays a big part.

Re: PLA adeshion

3.0.6 brought back the bug of minimum Z, which is 0.2mm again. But demo print Marvin is sliced to 0.12mm first layer, so you get underextrusion in first layer, because the nozzle is actually 60% higher than assumed in gcode. In next layer, which is (according to gcode) at 0.22mm, gcode assumes 0.1mm layer height, but the nozzle actually rises only by 0.02mm, so you get massive overextrusion.
Reslice it using 0.2mm first layer height.

Probably need to make a forum rule: if you're going to complain about first layer adhesion, you have to post a photo of what your first layer (underside) actually looks like.

Re: PLA adeshion

Fixed. I set (slic3r):

- First Layer speed lowered to 40%
- No fan for first 3 layers
- 70C Bed for the first layer (maybe with the two above is useless)

Now the first layer is perfect. However I expected that the one of the demo prints didn't require such tunings...