Use model as a support

[Nett 0]

Hello,

 

Could you please tell me if it's possible to have a 'floating' support in cura? I have a model of vase, and I need to keep vase's arcs tight, while printing.

I would like to place support models along a main model without plrinting supports from very bottom. Is there a way to make it work like this?

Unfortunately I couldn't understand how to use model in support mode. It pushes out main model when I try to place it at needed level, and support model sticks to build plate when try to put it at needed position.

 

Or there are other solutions for this particular case?

I've attached stl files of vase and support model.

 

 

Thank you in advance!

SupportComponent12.stl

Vase-2.stl

Edited May 29, 2018 by Nett

[mnis 11]

Hello too ?

You have to create two individual models and later reassemble them into one unit in Cura, so that it can be differentiated in Dual Extruder which extruder has to fulfill which task.

 

Alternatively, you can integrate single-extruder support material into a single model. Then each piece of support material requires a break mark at each contact area.

 

It is also possible to create support material as a model in the model. Cura recognizes such models in the model and prints them exactly at the desired position. In this case distances to the main model work well if they have 0.10 to 0.15mm area spacing.

[geert_2 558]

I have no experience with dual-nozzle printers using dedicated support material, so I won't comment on that.

 

But in single-nozzle printers like the UM2 you can design the support as part of the model in your CAD program. Theoretically it doesn't matter if the pieces are connected or not. Both will slice and print. However, if totally unconnected, the support pieces might fall down of course, or they might sag too much. So it is best to design-in tiny connection strands, which you cut off later. Also, tiny gaps between supports and real model will cause occasional hairs and strings, which you also need to post process later.

 

Before doing this on the whole vase, thoroughly try and refine the concept on a simple test piece that doesn't waste too much time and material. It might take a few iterations. Steep overhangs may sag down, or may curl up.

 

For example: if I want to print this table below without supports all the way down to the floor (which would destroy the text), then I need a sort of "hanging supports" for the overhangs. This was just a quick test to try the effect on my printers. The great idea came from user smartavionics, who is developing an automated method for bridges. You might consider a similar concept to stabilise the vertical bars.

 

This is a small model: the walls are 1mm thick, and the table is ca 15mm high. Printed in PLA, 0.1mm layer height, 0.4mm nozzle, probably at 210°C and 50mm/s. The connection strands are 0.5mm wide and 0.2mm high. If I remember all this well...

 

The concept: table with overhangs. The hanging parts with the ribs are the supports.

 

Raw print. In the center piece of the bridge, the supports tend to sag down. At the outward edges, the support tends to curl up. The staircase in the design minimises this effect, compared to a triangular shape, but still.

 

Print after removal of the supports. Text characters are 3.5mm cap height.

 

 

[Nett 0]

Hello @mnis, thank you for your pieces of advice! And sorry for my late reaction.)

 

You've mentioned that "It is also possible to create support material as a model in the model", could you please tell me what tool should I use, to make cura recognise support model inside a model? I created my model in Fusion 360, and I didn't find any features in there to set a part of model as a support. And single extrusion is preferable for me, it will build needed model faster.

 

Thank you,

Oleg

[Nett 0]

Hello @geert_2, thank you for your advice! And sorry for my late response.)

 

Your sugestion and example are very cool, but I'm not sure that I can create a good support construction in CAD program the way you've described due to my CAD expirience, or I might spend couple of weeks to complete it ))

 

Thank you,

Oleg

[mnis 11]

Hello @Nett

The simplest solution is possible with any design software.
First, you construct your model as usual. And while constructing, you think about which position the model should ideally have later on the buildplate, so that as few as possible to no overhangs are to be printed. In the case of the vase, it's easy and obvious how it should be positioned at best, but on many other things, one often has to make a prioritizing position selection.

When your object is finished, you can put it in the slicer for visual inspection and enable the support material options. In the Slicer you will find options to select different views. Take a look at how the slicer positions support material so that you understand the procedure. Also, you can often determine from which angle an overhang is recognized as an overhang to avoid unnecessary support material.

But in many cases you are not satisfied with the automatically generated support material. And then you have to do something extra. Your vase may not require support material, as long as it is large enough and printed as slowly as possible. But of course it depends on the abilities of your machine.

You can integrate self-generated support material into your object in two ways:

Either you do it the way you already showed it in your picture, where the support material has a very thin but direct connection to the object, then the slicer sees everything as a single volume and tries to print it exactly like that. Your support material must always have at least the thickness of the nozzle diameter everywhere.

NESTED INSTANCES...Or you position all support structures without direct connection to the main model. Here, a minimum distance of 0.10mm and a maximum distance of 0.20mm should be selected. Depending on the slicer, material and machine, the distances that work well vary, and so you have to approach the optimum with a few tests. But here, too, the support material may not be thinner than the nozzle diameter. As a rule, the slicer also sees these many individual volumes as a whole object to be printed and tries to print everything exactly at the selected positions.

The second option is best because, for example, you can make a separate component from the entire support material in the design software. If the object coordinates of the vase and the support material match each other even though they are in two separate files, then later on, for example, you can enable the slicer to generate a GCode for two printheads

 

For multi-color 3D printing, it is a bit like piecing puzzle pieces together. For each individual print head / color, an object file containing the areas to be printed is required. And the slicer generates a chain of commands for the 3D printer, so that knows when and where which printhead must be active.

Images: Two volumes with matching coordinates in a single STL file.

Edited June 6, 2018 by mnis

[geert_2 558]

16 hours ago, Nett said:

Hello @geert_2, thank you for your advice! And sorry for my late response.)

 

Your sugestion and example are very cool, but I'm not sure that I can create a good support construction in CAD program the way you've described due to my CAD expirience, or I might spend couple of weeks to complete it ))

 

Thank you,

Oleg

 

Yes, sometimes designing complex custom supports takes a lot of time. Especially if you need to make special provisions to remove the supports from difficult to access or critical areas. Then you need to design-in all required gaps, connections, openings for inserting pliers and knifes, etc... It may require testing. I consider all this part of the designing process. It is a bit similar to making moulds for casting in traditional arts, like bronze-casting: such moulds also require a huge amount of thinking and trying.

I consider arts not only as the creation beautiful things in mind, but also as the *technology to make them a reality*. There is a whole lot of difference between (1) having a beautiful picture in mind; and (2) being able to paint that in oil paints. The painting requires a huge amount of knowledge on perspectives, changes of light with distance, color theory, and mixing pigments and oil bases. It is mastering this knowledge what makes an artist an artist. The same is true for any other art, like music, sculpting, photoshopping, 3D-editing.

 

So I would suggest that you spend the required study- and trial-time to get best results. You won't regret it.

 

Practically, if I had to print such a vase, I would probably add a couple of little plates like this in-between the vertical bars. And then copy and move them around with functions like "pattern" and "revolve" (or whatever their names in your software), and finally merge everything. I would probably do a set at 1/3rd and 2/3rd height. But I would first try the concept on a small test piece, before doing the whole vase. It will probably require a few iterations. Designing this plate only takes a few minutes. And cutting these out will require post-processing and sanding.