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I've had a look at your GCode and it seems to do what I would expect. E.g. it prints a layer ending with support, let's say this is using nozzle 0. When it moves to the next layer it's keeping nozzle 0 selected and begins printing support again, this time slower to allow it time to cool. The nozzle is then switched to nozzle 1 and the main part is printed at a higher speed. We go up a layer and begin printing the main part at a slower speed. Switch tool, print support fast and so on...
I have tested it, and you can get a lower estimated print time by lowering the minimum layer time setting.
In terms of the support interface, as far as I can tell in the GCode you have sent you don't have support interface layer turned on, this can be turned on using a custom profile.
I hope that all makes sense 🙂
@George: The behaviour is different in the lower part of the print, where the dual head switches between model material and support material and in the upper part of the print, where only model material is used.
Attached is a screenshot of the robox gcode I posted earlier today in Simplify3D. In Simplify3D the different print speeds are shown in different colors. In the bottom section of the bone the print speeds switch between dark blue (very slow) and green (full speed of the print profile) every layer. This happens to model material and support material. For each single layer this violates the rules for minimal layer time. It is either too fast or too slow.
The top section of the symmetrical bone model has the same layer area for the model material, but there are no jumps in speed from layer to layer. Up there the rules for minimal layer time seem to work.
During printing the bottom section this looks really strange. The concept of minimal layer time is violated every single layer up to the height where the supports end. And the slow speed is really glacially slow.
Please try this print job on one of your Roboxes at CEL. I am pretty sure that you will not like what you see.
This is another exaample for the print speeds going hayward on dual material prints.
The first three layers are nominal.
From the 4th layer upwards the print speed toggles from normal speed to first layer speed every layer.
You can see it best on the left cube printed with material 1.
Is there a way to see the print speeds in the preview of AutomakerPro?
Perhaps I'm not understanding your issue correctly but I'll try and explain as best I can why you are seeing this speed change. I've added a picture of the G-Code from your dual cubes slice visualised in a development version of the G-Code viewer. This version allows me to colour by speed (this functionality will go into a future release). Dark blue is slower, lighter blue is faster.
So, in the picture I have highlighted some continuous lines of G-Code, this is all from tool 1. It basically highlights the end of layer 19 and the beginning of layer 20, before the tool then changes to tool 0. What you can see is we are going from fast to slow, and this is mostly to do with how long it has taken to print the part below. Since these parts are very small, that part of layer 19 using tool 1 is done very quickly, moving to layer 20 and printing at that same speed could cause issues if the material hasn't properly cooled, this is why it is printing slowly.
In order to increase the speed you have a number of options:
- You can reduce the number of seconds for the "Go slow if layer time is less than" our default at the moment is 15s seconds which is much longer than the time it takes to print the layers of these models.
- You can increase the "Minimum print speed" setting, at the moment the default is 8mm/s.
- You can increase the printing speed while printing using the printer tweak settings on the status page.
Of course I imagine changing the speed will give you various different results but it might give you the print time you are after.
Have you tried printing any larger parts? I imagine you see less difference in speed layer by layer?
Let me know if I haven't answered your question.
@George: Thank you for your detailled explanation of how minimum layer time is spread over two subsequent layers by Automaker. With customized print profiles it is possible to change or avoid the resulting speed jumps when printing small parts. Other slicers take a different approach to achieve sufficient cooling time for small layer areas. I apologize for not understanding your concept in the first place.