Pile up objects and attach them for mass 3D printing

Question

I'm completely new to 3D-printing. Because of Covid-19, my dad got a Dagoma Magis 3D printer and we are printing protective visors for hospital workers here in France.

We have been given a 3D model that we can simply load on the printer and it works pretty much alone. The 3D-printed part is quite small and very flat so we thought about piling six or seven of them up so we can let the printer work during the night. Then in the morning we would simply have to detach each piece from the pile using pliers. I thought about doing this using Blender (I know nothing about 3D but I've heard Blender is a good tool for that). In fact, I started by posting this question to the Blender stackexchange, which redirected me here.

This is the piece (or two pieces, actually) that I want to pile up.

My strategy would be to extrude small cylinders to the shape from different points and copy and paste the model several times. The end result would look like this:

The yellow bits are the cylinders I want to insert to separate the different parts. So when it is printed, I can simply cut them to separate each visor.

To do this, I think the best way to proceed is the following steps:

• Load up the model as I did (imported an STL file)
• Add some tiny cylinders (or another shape) on the top of it by extruding them
• Copy and paste the shape and move it along the Z axis to pile them up
• Fuse everything together and merge it as a single item
• Export as STL
• Put into 3D printer.

Is that a good strategy? How should I proceed?

I looked up everywhere at how to extrude a cylinder, or copy-paste a shape and attach it together, but in vain. I'm too clueless about Blender to figure how to do this. I could only manage to make a circle spawn at the origin of the plot.

I know stackexchange is mostly for professionals and this is a beginner question, but this is a quite peculiar situation. I really want to do it fast, as the quicker we print the visors, the faster the medical staff can have them.

Also, if you recommend using anything else than Blender, I'm up to anything.

Answer 1

Don't modify the STL to separate the visors with cylinders. The rest of the part is unsupported, so this will give you lots of support structures or, if omitted, a gigant spaghetti print.

Josef Prusa is already printing stacked visors on his print farm overnight.

I would stack the models of a set of visors in my slicer and for each visor added after the first disable "dropping print to the build plate" and position each consecutive visor one layer height (e.g. 0.2 mm) higher than the last layer of the previous, this way you use the previous visor as a raft for the next.

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Below, a reference of someone who prints 8 parts stacked (4 high) overnight:

I wanted to be able to print more than just 2 at a time. Specially over the night when everyone is sleeping. I came up with the idea to stack them on top of each other. Instead of 2 you could print 8 during night. If your printer has smaller build plate and you can only print one its also big help for you.

After printing jsut simply peel them away and they will break loose.

Gap between parts is 0.3 mm .