Stringy bottom

[jimc]

well i cant say what impact the slicer puts on the overall model with the offsets since i never use that method. with the bolt you are setting the zero point.

[Jules]

Have you ever done an extrusion width calibration? Usually, if the height of the square is exactly 2.0 mm, you will get a more filled-in first layer.

Hate to tell you to change the Z-Offset again, but try changing the Z-Offset number to -0.25 mm and run one more square, then take a picture of the bottom so we can see what it looks like. Don't bother to measure the height on that one, I just want to see what the bottom looks like.

[scampa123]

Have you ever done an extrusion width calibration? Usually, if the height of the square is exactly 2.0 mm, you will get a more filled-in first layer.

Hate to tell you to change the Z-Offset again, but try changing the Z-Offset number to -0.25 mm and run one more square, then take a picture of the bottom so we can see what it looks like. Don't bother to measure the height on that one, I just want to see what the bottom looks like.

Okay will do, just heating up the bed...will take a few mins!

[jsc]

The "correct" procedure requires you to calibrate your extrusion width first, then adjust the Z-height.

A comment on first layer setting in Simplify3D: some versions ago (I don't know if this is still the case), using the first layer percentage setting did weird things. If you set it to < 100%, it would lower the first layer, but also lower the extrusion to match, and if you set it to > 100%, it would actually print the first layer at the normal layer height but increase the extrusion. I don't know if that's still the case. That is why I prefer to use 100% and use the gcode z-offset to control the first layer height (actually, it's usually set at 99% or 101% just to avoid some Simplify3D bugs when it encounters a vertex at exactly a layer boundary).

[scampa123]

Have you ever done an extrusion width calibration? Usually, if the height of the square is exactly 2.0 mm, you will get a more filled-in first layer.

Hate to tell you to change the Z-Offset again, but try changing the Z-Offset number to -0.25 mm and run one more square, then take a picture of the bottom so we can see what it looks like. Don't bother to measure the height on that one, I just want to see what the bottom looks like.

Here is the calibration cube at 0.25mm

[scampa123]

I will note that both the .20 and .25 feel smooth to the touch on the bottom (vs the top where you feel the infill)...despite the look of the threads...

[Jules]

I'm going to solicit Jim's opinion on that one. I think it looks a lot better - no gaps between the threads that I can see, but the wavery bits around the edges might be just a hair of overextrusion.

One last adjustment and print - change the Z-Offset to -0.24 mm and print one more. (It's so close now that this is just me aiming for perfection - that would actually probably be pretty good.)

[scampa123]

I'm going to solicit Jim's opinion on that one. I think it looks a lot better - no gaps between the threads that I can see, but the wavery bits around the edges might be just a hair of overextrusion.

One last adjustment and print - change the Z-Offset to -0.24 mm and print one more. (It's so close now that this is just me aiming for perfection - that would actually probably be pretty good.)

Okay working on it now!

[jimc]

there you go. thats much better. now you have that done print a thin wall cal cube and tune the multiplier if you havent done that yet. i think you said you did it already. in any case that is how the bottom layer should look. as your finding out, the perfect first layer is a super precise setting. this is why many of us are always looking for that perfect flat build platform. just a touch off and the gap is either too big or too tight.

[scampa123]

I'm going to solicit Jim's opinion on that one. I think it looks a lot better - no gaps between the threads that I can see, but the wavery bits around the edges might be just a hair of overextrusion.

One last adjustment and print - change the Z-Offset to -0.24 mm and print one more. (It's so close now that this is just me aiming for perfection - that would actually probably be pretty good.)

Here is the z offset set to -.24mm :