Taz 6 Heated Bed Variances?

I have a Taz 6 that is working great but when I print large contact surfaces the first layer has this effect in it. It doesn’t effect the overall print but was curious…is this because of variances in the temperature of the bed or surface variances? When you run your hand across that area I can’t feel any bubbles or differences but these layers are at .1mm so maybe even the slightest amount shows?

This is as it lays down the 2nd layer.

Hard to tell, but it is probably slight surface variation (perhaps slightly stretched PEI/adhesive from previous print removals) causing thin extrusion in those areas. The usual protection against that is a thicker “first layer”. Even if printing at 0.1mm, I would suggest a first layer height at least double (and perhaps triple) that.

EDIT: Looking closer, it may be that you are starting too close to the bed. I can see that each line of extrusion on the first layer is thinner in its center, with thicker areas at the edges where the plastic has been forced to the sides. Again, a thicker first layer is the easiest solution. But if you really want the 0.1mm first layer, you might try adding 0.02 to 0.05 to your Z-offset (either in slicer, or via M851). That may be enough to lessen the gaps you are getting on the “high spots” of the surface.

Cool - thanks! I will give that a try (I am slicing with Simplify3D). I am already using a .08 offset because it literally was so close it was barely able to squeeze any filament out… (this was with the Simplify3D Taz 6 profile). So I bumped it up to .08. But I have never adjusted the thicker first layer. I will see if I can locate that option and boost it. I also adjusted the extrusion multiplier from .90 to .95 because I was not getting my layers filled fully and that fixed that issue.

Note with Cura…it was never an issue - their first layer is always thick/perfect. But I love the supports and interface of Simply3D better so been trying to get it dialed in to be as good as cura.

Cura has a “first layer height” expressed in mm. I believe all the default profiles use 0.425mm for first layer.

In S3D, first layer is set as a percentage of layer height. Go to the “Layer” tab, and look for “First layer height”. If you have specified 0.1mm for layer height, I would recommend trying 300% for first layer height, which will give you a 0.3mm first layer. Or you could go all the way to 425%, which should give you a 0.425mm first layer as in the Cura profiles.

Let me know how it works!

In S3D, there’s also a secondary setting for the first layer… make sure to check those also. Its on the “Layer” tab, one of the settings lowers the nozzle again…

You could try a multi-process print, with a .2 initial layers (2-5) then the rest of the project at .1 layer height.

Not sure what you are recalling, but there is no “secondary setting” for layer height on the layer tab. There is “primary layer height” which applies to all layers, and “first layer height” which proportionally affects the first layer only.

Good point about multiple processes, which are useful if the primary layer height needs to be altered somewhere other than just the first layer. The ability to have multiple processes defined for the same print is a really nice feature in S3D.

Yes. That’s the setting I was referring to in the Layer tab.