Designing Good supports for Arch Houses and Buildings

[ian 32]

As many people know I am testing the conversion between arch archicad 3d models and printing with the ultimaker printer.

My question here is, if i have a large store hall model, big amazon sized thing but with no internal supports (columns) i have a very hig external wall, flat roof and then some heavy roof details.

What is the best strategy for modelling supports.

a few small supports or one big one in the middle of the model from floor to roof ?

also what is more effecient ?? square or round suports. Round looks nicer but maybe square supports are easier and faster for the movements of the ultimaker ??

Here are a few pictures of what i am talking about.

Ian

[ian 32]

the archicad hall.

[ian 32]

here is the idea i am playing with at the moment.

straight wall likes supports that should carry the final weight of the roof from start of print. also because it is a straight wall, the print head can follow it up and down and well, its just a easy object for the printer to handle.

I guess there are a million other options for supports and I cant wait to hear them ??

thanks guys.

Ian

[ian 32]

the support walls are half a meter thick. these models are normally printed at 1:500 scale. so that would make this wall 1mm thick ?

is that too thin ??

Ian

[ian 32]

just for fun i did the following.

archicad export to 3ds

opened 3ds in cinema4d and cleared out all the lighting and material crap.

saved out as stl.

uploaded stl to netfabb cloud and after 3 minutes just got back a clean copy of the model.

now im going to give it a run through skeinpypy for a minute.

Ian

[ian 32]

i just cut it with skeinypy.

27 seconds after cloud repair ?? thats fast ??

Ian

[ian 32]

here is the link to my file if anyone wants to try some prints.

http://www.thingiverse.com/thing:22659

Ian

[ian 32]

i just updated my model a little on thingiverse, so that the model is located on the axis and not 6km away.

Ian

[alaris2 1]

you appear to be having a conversation with yourself Ian

for what it's worth, 1mm is fine for a support - any less is likely to fail. I have some test prints I did somewhere that show that. I suspect 0.8mm is actually the minimum guaranteed support.

as with all things, speed matters - faster requires more support. anything that has infill requires slower or more support. it's better to have the support a multiple of the perimeter thickness is my recommendation.

as an example. I printed a 1970s shatterline lampshade which I redesigned to have an extremely thin wall on one side (to let light through) and thick on the other (to reflect it). I originally tried with 0.4mm thickness, but it failed half way up. several tries later and 1mm worked fine for a 20cm high object.

[ian 32]

i love talking and if no one is here to talk to me, then i keep finding myelf.... :roll: :lol: :lol:

Thank you for your recommendations. I think the 1mm is pritty good for support.

I would love to see a photo of your lampshade! did you take a photo by any chance ?

Thank you.

Ian

[ian 32]

i would like to call my actions. self documenting and not just talking to myself. sounds better ! :lol:

ok i have started looking at the next house in this 5 house model set.

This building on plan is in the forum of a L.

I have holed out the interns, so its nice and clear and empthy.

My question is, what is better ??

printing the angled roof with no supports and hope that the plastic cools fast enough, that it does not bend in ??

or build a few rough supports under the roof, so the printer can start building a bridge (doesnt have to be pritty) and then the bridge will come up and meet the bottom side of the roof.

Then the roof is printed with 2 or 3 ledges for extra support ??

could work ??

Ian

[ian 32]

also i have placed in supports now from the base of the model to the roof, so the roof hs a good strong support from the base.

the next question is ? do i need one long support in the other direction... ?

I think when I have these first supports, the extra long support is not nessesary... ?

a work in progress.

Ian

[alaris2 1]

the roof will sag with no support. experience says so.

I tried 2" with no support. first couple of layers actually worked fine and I had high hopes. then it put down a layer of infill and the zigzag motion and weight of material caused the bridge to sag. I suspect heat from the higher layers also affected this. I think I still have this model so you can see the effect. I'll try and take a photo of the lampshade tonight too.

[italianmaxx 0]

Maybe I'm a bit off, but did you try with different infill % ?

When I printed some thin wall (a vase like objects) I got an external wall a littel bit on the soft side, not a good sturdy wall.

in netfabb maybe a 10mm infill space (to set in the print tab of the right menu) could do the job of supporting roofs and make walls a little bit rigid and at the same time don't waste too much PLA or time, if you set a STRONG line /FAST speed extrusion.

I will try asap with your model.

OT: did you see the zprinter inkjet colour 3d printer... :shock: :shock:

[ian 32]

if you want something nicer to test.

I just did this one today.

http://www.thingiverse.com/thing:22704

the exact same principals but with some nice old facade detailes.

Ian

[alaris2 1]

an ugly house, but nicely printed !

I put a copy of my lampshade in the 'what you printed' post Ian.

[italianmaxx 0]

Yee, the 'colour' house is really ugly, but look at the colour and texture....

Back to the topic, Ian, why are you working on printing hollow models? Is this really needed or a normal infill or inside support could do the job?

Bridging is An art itself in the 3d printing art...

I'm also thinking about print the hollow house upside doen or in 2 pieces and then glue it togheter

[ian 32]

i thought hollow models are more effecient because i want to print many larger models 150mm by 150mm for example and i want to show my company that i can build these models using effecient amounts of material.

Also I was thinking about splitting my model up for printing.

It makes sense.

Printing a successful roof and then each level of the building with internal walls. then it would besome standard to have each model that can be opened and customers can see in the internal workings of the model..

Can I ask, what is the benafit of printing your model upside down ??

Thanks.

Ian