Stop - Start printing height questions/problems

[rolfmeijer]

I try to print a single model with multiple processses to save print time.

Question 1:
After slicing there is a gap between the processes visible in the preview. This gap is also visible in the print.

It looks like the stop height and the start height are equal when S3D calculates it.

So I tried calculating the exact height myself.

First process height
First layer Height = 180% x Primary layer height 0,150 = 0,27mm
99 layers x Primary layer height (0,150) = 14,85mm
Total for 100 layers = 15,22mm

So the First process stop height = 15,22mm
And the Second process start height = 15,22mm

But using these values still gives a gap in preview and in print. What am i doing wrong?

Question 2:
On of the processes needs a bottom layer for an overhang. But the bottom also gets printed inside the model. I don't expect this because the model is closed. The problem is, the overhang is only a few cm2 but the complete model is almost 100 cm2. So this takes a long time to do a 3 layer bottom surface which i try to save. How can i prevent S3D from making solid bottom layers inside the model?

Any thoughts/tips/tricks are welcome

Rolf

[dkightley]

Hi Rolf

When setting up multiple process for printing one model, you need to turn off the settings that affect the top of the bottom half, and the bottom of the top half.

On the lower section: Top solid layers to zero,
On the upper section: Bottom solid layers to zero, First layer settings all to 100%

One thing you will need to watch out for is where there is a downward facing surface on the upper section or an upward facing surface on the lower section. If you either, then you will have to leave the relevant top/bottom layers alone and suffer some solid infill layers at the joint!

To check you have the changeover from one process to another at the right, you can simply preview one of the processes on its own. And as far as I am aware, the start distance for an upper process should be the same as the stop distance for the lower process. I think S3D is clever enough to work out what layers need printing if you get the changeover out of sync with the layers. I don't think you need to do any calculations yourself to set the distance at a layer boundary.

[jimc]

The gap you see is from your start/stop setting not landing in the right spot on a layer. You will only see this occasionally. If you see a gap in the preview adjust the start stop heights up or down by .05mm at a time and it will go away.

[dkightley]

...which has also taught me something!
I thought S3D worked in multiples of layers when changing process. From what JimC says, it doesn't.

[S3D-Jason]

After slicing there is a gap between the processes visible in the preview. This gap is also visible in the print.

For Question #1, I wanted to add an update to this thread to mention that Version 4.0.1 added several improvements in this area. The software will now automatically ensure that you have a smooth transition between processes, regardless of what layer height or start/stop settings you use. This makes it much quicker to setup these prints and allow the software to handle this math.

I tested the setup mentioned at the top of this thread now works correctly in Version 4.0.1.

[Johnm]

where did Start/Stop printing at height go to in version 5? I see a Wizard for it. Is this what I am supposed to use?

[S3D-Jason]

For V5, that option was relocated to the "Custom Zones" button in the bottom left of the process settings window.