I’m trying to print with dissolvable supports, but I want to minimise the wasted material by only using dissolvable material where the interface is flat.
I have an architectural model to print, so it’s made up of lots of flat slabs which lend themselves perfectly to a dissolvable interface underneath that only spans a few layers. Other parts of the model are ramps, but I don’t want dissolvable interfaces for their supports otherwise this interface will span many layers requiring a filament change (and poop) every layer. Ideally I’d be able to print it all in a couple of prints and not have to assemble a model from individual floors (the building is very complex with weird floor heights and mezzanines).
I thought to split the model into parts where the flat slabs can be printed with different support settings, but I don’t think you can have different support settings for different parts. My best solution so far is to manually model the dissolvable parts. This kind of works, but it’s not ideal.
I see your problem very well…
Currently designing a siren for a salvaged motor.
And as I like things (very) different for this one the rotor requires and awful lot of support…
I eliminated most of these support by using the default support with a snug fit and by setting the support angle to just 10 degrees.
Leaves a bit of a mess inside the rotor but has little effect on the performance.
You did not specify the material for the model but I assume it is either PLA or this lightwieght stuff for RC models.
Probably PLA due to the costs…
I mainly use PLA and have NO need for a special support or interface material.
Even complex support structures are printed in the same PLA as the model, unless I require easier visualisation.
All a matter of finding the correct spacing for the surfaces AND the interference layer.
In the case of your example and starting from the defaults for a 0.4mm nozzle:
6mm (normal) support spacing.
0.4mm interface spacing.
Three interference layers.
0.22mm distance between supports and model (top and bottom of the supports).
You can then also set the tick for only supporting critical overhangs and to NOT support bridges.
This should leave you with surprisingly few supports to remove and they should come off clean and leave an acceptable finish on the bottom of the supported top part of the model, the bottom where the supports start should out perfectly clean.
But for all complex problems there is often a far easier and often faster solution…
IF you could use a modelling software to separate the top and bottom you could just join the two by having matching holes in one part and correspondingly longer stand on the other part.
Another often overlook option would be to turn your model by 90 degrees so you only have to support those pillars making the support removal a breeze and speeding up the time required to print the model.
Of course you can apply the above to your support material as well.
This however means flushing out a lot of filament and paying for dedicated support material without actually having a real need for it.
Just saying
Yes, I’m using PLA and this has been fine for supports for the most part. The problem is the model is very complex with delicate thin columns and internal volumes that are very tricky to remove supports from. The screenshots are of a very simple example to demonstrate the problem. I can’t show the real model for obvious reasons. The idea of dissolvable was to make this process easier at least for most of the hard to reach areas.
As this is something we are going to be doing a lot in future, we really want to minimise the time and effort (and potential breakages and reprints) from assembly. If we can leave the machine running overnight or even over the weekend, this would be preferable to spending days assembling.
Yeah, using dissolvable for whole support would be very expensive and make a lot of waste. I’m trying to find a good solution to using / recycling the poops, but I really want to reduce the plastic waste as much as possible.
OK, I think I’ve found a better solution. I was thinking backwards!
Autogenerate supports with dissolvable interface but with a threshold angle of 1 deg and manually model all the other supports as a separate part (or automate this in grasshopper or something). I made sure the manual supports are offset by 1 layer height (0.2mm in my case) from the top and bottom.
I think there is just too many cases for support to have them work automatically AND properly all the time.
What I would like though is an easy option to mix different types of support on the same model…
I think that’s a good idea for this simple model, but I don’t think this would work for what I’m actually trying to print. I’m sorry I can’t show you what that looks like.
I’ll give this a go though, thanks for the suggestion. There’s no harm in trying on a small area I suppose (other than a little wasted PLA)
I’m not an architect but I studied it a couple of years and made some models in foam board ^^
Another approach would be to cut the model by floor. That will require a little bit of assembly. But you will most probably reduced the overall print time (less support and/or no special support support/AMS needed).
Yeah, that’s probably how I’ll have to do it in the end. I just wanted to find a better workflow. The ultimate goal would be to decrease person time by increasing machine time. I don’t mind if it takes longer to print as I can leave prints on overnight. The main problem is all the wasted plastic with AMS poops. In hindsight, I probably should have got a printer with 2 printheads - Bambu lured me in with their pretty machines
You might be surprised what is possible with proper bridging and calibration.
I had a wake up call when I started a big print after slicing it that had support requirements like yours.
You know, long flat areas with nothing below…
Left the machine printing over night with no worries, removed it the next morning and found no support but a still very acceptable print…
As mentioned above so often:
Whenever you can try to check if a different orientation provides a big enough saving on support side of things.
I learned over the years that creativity starts with the design but won’t end with clicking on the slice button
I gave your example a try in Sketchup and then printed it standing up.
With snug supports those pillars come out perfectly and I had no issues removing the few supports between them.
Without supports and the pillars 4cm long and horizontal there was a surface difference visible from the bridging but not enough to say it would be noticed unless you stare at it at close range.
I can only assume that you use downloaded models for your creation mixed with some custom models…
If you know how then just think about splitting some models to assemble them after printing…
For your examples it would only take a few minutes to separate them, create the holes and to extent the pillars.
Just saying …
That’s very encouraging, thanks! I tried with no supports and ended up with a spaghetti mess. I think the distance between the pillars in a real building can be much greater than what you need to support a flat area when printing. At 1:500 scale which I’ve been doing, anyway.
The model I’m printing is an architectural model from some BIM software, it is very complex. I’m worried printing on the side wont work for the actual model as there are a lot of very thin columns (diam 0.8mm). There are so many that it would be a real pain to add them after, even if I left holes for them. I don’t think they would be reachable.
The way I see it now is there are 3 options:
Print is as it is and pray to the 3D printing gods that it works with no supports
Print in separate parts and spend a long time assembling (it’s a very big building, we’re talking about maybe 50 separate prints)
Print with some custom supports that are easily removable even when you can’t really get in the model to remove them
On point 3, I’ve made a quick Grasshopper definition to generate supports for non-flat areas in Rhino with a base around the bottom I can print in PVA and dissolve away. The supports for the flat area can autogen with a dissolvable top interface. Then all supports have 1 dissolvable interface that makes it easier to remove and it only has to change material twice per interface.
Here are some screenshots of a small area of the actual model. I don’t think it is a problem to show this very small part.
did this approach actually work? am grappling with a similar problem - i have a PETG model with a load of supports but i only care about the scarring at the bottom and the top of the model, so I’d like to use default material for all supports apart from the top and bottom…
