Idea to speed up printing with a smarter slicer


#1

I’m printing a build platform chock full of max detail level earrings in the purple castable resin. Printing time is estimated at about 33 hours. There are 1843 layers in the print and I’m using default supports for each earring.

It turns out that about the first 250 or so layers are 100% supports. I don’t need them to be super finely detailed. After all, I’m going to remove them and throw them away!

Now, I understand that for technical reasons, everything printed on the same layer has to be the same thickness.

But is there any technical reason why the first layers, which are 100% devoted to supports, couldn’t be printed at draft resolution, with the more detailed print resolution starting say 10 layers before it’s needed?

The slicer software would need to be smart enough to know the difference between a support and a printed object I designed – and it already knows that!

It would have to be smart enough to know that (with me making up numbers just for illustration purposes), that one 100 micron layer is four times as tall as a 25 micron layer, so for that first 240 layers, it would only need to print 60 100 micron layers, then switch to 25 micron layers afterwards.

It seems to me that in this example, we would save on the time to print 180 layers, or about 10% of the print time would be shaved off with a fairly simple software improvement.

Or is it already doing that?


#2

Just first up: I don’t work with the Castable Wax resin so I can’t tell from experience.
But: When I open Preform (3.13.0) and select a Form 3 with Castable Wax, I can select “Adaptive” under “Layer Thickness” which automatically slices the model into 25µm to 50µm thick layers across its entire height. Maybe this helps. Unfortunately Preform doesn’t offer this option using a Form 2, at least with this type of resin.
Maybe lowering the “raft thickness” and the “height above raft” in >supports< - >advanced settings< could also be an option.


#3

Thanks! I will look into this!


#4

I just read the description of it in preform. It says it will adapt the micron size according to the PART GEOMETRY.

I pretty much want the PART to be that max fine level of detail I want the support structure to be in draft mode where it doesn’t interfere with the parts.

I’ll give your suggestion a try on my next print and see how it goes. Maybe I’ll like the way they did this more than my idea! Thanks again!


#5

I just changed the settings in the slicer to be adaptive and took a look at the layers one by one using the slider on the right of the screen.

It is changing the micron size according to the PART geometry. So, although the supports will print much faster, the piece will print with less detail in places. If the algorithm works perfectly that won’t matter. If not, well, my idea would be a good compromise option.

The above was based upon printing a single piece.

On my current print run I have 22 pieces of six different types. I checked the slicer layer by layer and the effective result was “print fast on the supports and print finest detail on any piece”, which in effect is what I was asking for! With a single piece it could attempt to optimize. With lots of pieces I didn’t see any optimization. Print time dropped from 34.5 hours to 26.5 hours, which is a pretty righteous speed improvement.

I haven’t tried all of one type with all the exact same orientation.


#6

In the advanced settings for Supports, you can change the minimum height above the raft that the model will be positioned. It defaults to 5mm. I have reduced that by half with the only problem being the short supports at the bottom were a little harder to pull off.


#7

Thanks!