In today's video I want to introduce you to tree supports and why you should use them more than
you probably do, but also how to tune them to work better, come apart easier, and use less material!
Tree supports have been available in cura since about 2019 give or take,
after being experimental for a while, they are now
very standard but they aren't default and it's easy to miss that they exist if you don't look
under the support structure menu here, where there's just "normal" or "tree".
Unfortunately prusaslicer still doesn't support tree...supports which is a shame because with
prusaslicer's recently implemented paint on supports that would definitely be a game changer,
maybe they are planning it, I've not heard anything, if you have let me know.
Back to cura, tree supports are useful primarily for parts that normal supports simply can't reach.
I began using them initially for miniatures, because if we look at this model here,
it's fairly typical for a miniature in that it has parts above the base that need support,
and there's nothing you can do, this has to have support. You can tilt it but you're
likely to have to do a lot of work to get to an angle that doesn't need supports from the base.
Now I know you have this option here in cura that can allow you to put supports up from
"everywhere" or "buildplate" but I recommend you almost never use "everywhere". Why? Well,
it usually messes up the surface it's supporting from, but worse than that, you often end up with
a lot of supports in places you either don't want them, or worse, places you can't remove them from.
Now this is a short video so I must stay focused on the topic at hand - tree supports
are by default usually set up in cura to be way, way too thick, by that I mean
dense, I'm thinking more of a 600 year old oak tree rather than what we want which is an espalier
and yes I'm showing off my gardening knowledge here, I've grown apples, I know my stuff...
Take this mushroom for example and I'm not an expert in mushrooms for sure,
but I am an expert in not being able to remove these supports.
Look at them. No way. And this isn't a tree support problem, this is a settings problem.
I'm going to give you some bad settings on the left here which probably match cura's
defaults or maybe they don't and I overwrote them somehow, but anyway I'm going to give you some
good settings on the right. I think this is as good a way as any to demonstrate the difference,
but it will no doubt depend on the model because a lot of these are in millimeters
when I suppose it would make more sense to use a proportion of the model size, maybe,
who knows. The aim is to just make them sparse enough that you aren't winding all
the way round the model and thus trapping the model inside. Preview is your friend,
never print a model with tree supports until you have checked the preview.
Moving on to the interface, tree supports almost never look right in terms of the
interface between model and support. Take this cat you might remember from last episode,
these supports really don't look like they will work but they pretty much will. If you want them
to move closer then you can in special cases like this set the support top distance to zero and it
will work well, but be mindful that doing this is not allowing any gap so on larger pieces with more
supports that would be glued, so a general value of around a layer height of gap or more is ideal.
If you notice the darker blue stuff, thats the support interface and it's
set separately to the support itself with all sorts of settings for density and resolution,
there's lots of scope for messing with this and it could pay off with detailed pieces like this.
Unfortunately it's another bunch of settings that I can't recommend specific values for as
it's going to need vastly different values for different sizes or overhangs of pieces,
you kind of have to try it and get a feel for how the preview will come out.
Finally in terms of thickness, so long as you have brims on and there are brims around your supports,
you can really lower the support density and wall count, I don't know if you'd ever
want a wall count of more than one. Using tree supports will save you a lot of plastic especially
if you thin them out and lower the density, and I've never had a tree support fail
other than when I have forgotten a brim at the base.
I think I should probably stop there but as I've said on previous days
this is something I can revisit in a full episode in the future and probably will.
It's already on my list. Which is, to be fair, a long list.
See you tomorrow!