First two support layer's print speed is too high when using raft.

[MansooR 0]

I'm using Cura 4.6.1, trying to print PLA + PVA combination.

It was very hard to stick the first PVA layer(support layer) to Raft so I took a look at my gcode, and I found those starting layer of support is too fast.

 

'Raft Print Speed' controls those speed of raft layers.

'Initial Layer Speed' controls the first layer of real printing part.

And 'Number of Slower Layers' controls those a few layers after the first layer.

 

But the first two layers of support is between raft and the first layer, so it's not affected by raft speed or initial layer speed, and always print with the 'Support Speed'

 

I think the first two layers of support is put into between raft and real print to adjust gaps regardless the airgap/z overlap values, and it works brilliant in the aspect of z height. 

But it always run with 'Support Speed', not 'Initial Layer Speed' so it is very hard to stick to raft especially if 'Support Speed' is high.

 

I couldn't find the way to control the speed of first layers of support. But if there is, Anyone knows about that, please let me know. 

 

Edited July 1, 2020 by MansooR

[SandervG 1,521]

Hello, if I get your description correctly you want to print a raft with PLA, then a layer of PVA and then your model again in PLA, correct? I think you are looking for the setting 'Support layer interface'. 

And I believe that initial layer is just the initial layer, not necessarily that one of the model or 'real printing part'.

[MansooR 0]

Hi, SandervG

 

I found that phenomenon while I'm trying to print PLA+PVA combination, but it is not  about combination.

It is about the printing speed of specific layers.

 

I'm using 'support layer interface' already but it affect between printing model and support, not between support and raft.

 

I attached a gcode that shows this speed problem.

 

I set profiles as below.
Raft Print Speed = 25
Print Speed = 100
Support Speed = 80
Initial Layer Speed = 10
Number of Slower layers = 5

 

Raft is from layer -6 to layer -3 and the printing speed of layer -3 is 25mm/s(F1500).
Printing speed of layer 0 is 10mm/s(F600), and printing speed is getting faster to 80mm/s(F4800) for support at layer 5.
But printing speed of Layer -2 and -1 is 80mm/s(F4800).

I think it is weird that printing layer -2 and -1 with full speed and then slow it down to initial layer speed at layer 0.
Layer -2 and -1 is first/second layers of support, so it is very important to stick the whole support to raft.
I was trying to reduce the printing speed of layer -2/-1 but the only way I found was reducing the support speed.

 

Is there any way to change those two layers printing speed only, not affecting other layer's speed?

 

 

CFFFP_support test.gcode