# Cura Parameter Confusion: Initial Layer Flow Rate

I have a LultzBot TAZ 6 3D printer and the software I use for my prints is "Cura LulzBot Edition - 3.6.3". Recently, I have begun to play around with the parameters in Cura relating to initial layer adhesion. One such parameter is the Initial Layer Flow Rate.

Now, after manipulating this parameter several times and evaluating the pieces that have been printed subsequently, it seems quite apparent to me that a manipulation in this parameter is affecting all subsequent layers that are printed.

For example, if I increase the Initial Layer Flow Rate from the default setting of 100 % to 130 %, layer 2, layer 3,...layer n all appear to be printed at at a flow rate of 130 % resulting in prints that are clearly "overextruded" (e.g. the finished surfaces are incredibly uneven, bumpy, etc).

Similarly, if I decrease the Initial Layer Flow Rate from the default setting 100 % to 70 %...all subsequent layers are clearly underextruded (e.g. walls are not connected at all and floor/ceiling have visible gaps).

Why is this happening? Directly above the Initial Layer Flow Rate parameter is a parent setting that is simply named "Flow". (refer to below picture)

Do I need to manipulate flow in order to avoid this from happening?

All I want to do is change exclusively the initial layer's flow rate (for better adhesion on larger pieces)...but my current method is not accomplishing this. Any suggestions?

$$\color{red}{\text{EDIT}}$$ - After reading the comments, I just wanted to clarify that I have let my parts "be printed to completion". The obersvations that I am making about underextrusion or overextrusion are in reference to the total structure (not just the first several layers). These are large structures (~12 hour prints).

• Hi S.Cramer, welcome to the site. You could include photos for better replies. Flow in 3d printers is how much plastic you extrude, so this sounds correct. There can be a residule effect (more melted plastic in the barrel) between the layers. Its not much plastic to be an over vs under. I'd let it keep printing and see what it looks like after 5 or so layers. Mar 10 '20 at 21:34
• @StarWind0 I think you may have misunderstood my post. I HAVE let it finished printing complete structures...using several different values for the initial layer flow rate. In all cases, it is evident that the initial layer flow rate has completely influenced the overall structure of the print. Hence the question. Mar 10 '20 at 21:55
• Welcome to the 3DPrinting Stack!
– 0scar
Mar 10 '20 at 21:55
• In the generated G-Code, flow-rate translates to G1 Xn Yn En.nnn (extrude n mm) commands. Cura marks each layer in the G-Code with "Layer: n". You could have a look, if the extrusion length differs for the same line in layer 1 and 2-n Mar 11 '20 at 16:36