How to hollow a model in Blender for 3d printing

How to create a hollow model in Blender even when there are lots of pointy bits. Usually for resin printing you want a hollow model and although slicers are pretty good at it, Blender can also be a good option for precise control and for easy hole generation.

[@rarstorm]

Simply the best hollow tutorial I've seen. Thank you so much for sharing knowledge!!!

[@notverygoodguy]

I'm really glad you think so. I was a bit worried it wasn't too clear what I was doing.

[@gbtygfvyg]

I honestly forgot I subbed to you. I used your guides to help me with a 3D printing project that ended up failing pretty miserably (porting an FFXIV model to blender and then getting it 3D-print ready) and I haven't attempted it again. Doesn't help that I basically threw myself in the deep end. However your guides were super helpful for some of my questions during the process and I appreciate the vids!

[@notverygoodguy]

Great to have you drop by :) I try to cover topics that could be useful for people not trying to 3d print things but I have to admit it is my focus. I hope you get the motivation to try your printing project again soon!

[@Buday-Jewelry]

Awesome. Thank you!

[@notverygoodguy]

Glad to help :)

[@DuyQuangDang]

Thanks a lot Not Very good Guy! Liked and subscribed!

[@notverygoodguy]

Good to have you on board!

[@PhilippSchneeweis]

I'am currently working on a very small object with sometimes a thickness of millimetres. So I think it's the best if I leave the hollow and make everthing solid in the inside. Is there a way to do that, or is any object already solid from the start and we just make a hollow to save resources?

[@notverygoodguy]

Any manifold object (has no holes in it, even tiny ones) that has no walls inside will be solid. In most cases this means that your model is solid unless you hollow it :) Hollowing is only really used for resin printing. if we are 3d printing with resin. Resin deep inside a model often won't cure and can later crack your model. So, people often hollow their model and make holes in it so that uncured resin pour out.

[@luke-fnb1328]

Would you recommend to cut the model first and then hollow?

[@notverygoodguy]

It's easier to cut a solid model than a hollow one so I would recommend cutting first.

[@luke-fnb1328]

Thanks!@@notverygoodguy

[@user-cr2bj7ey7n]

Very nice

[@notverygoodguy]

Thank you

[@earringtherapy]

I liked your method. After adding displace modifier, and I hit apply. It gives Report Error " Modifier cannot be applied to a model with Shape key." Any suggestion. I bought add-on to resolve this issue, that did not help.

[@notverygoodguy]

Your model has shape keys :) If you are happy with the model, you can remove the shape keys before doing the apply. They are in the little green triangle icon in the properties panel. In there is a little box marked shape keys which lists the shape keys you have. You can delete them by pressing the little "-" button but you must start from the first one and work your way down. I recommend saving the end result as a different file as your model had shape keys for a good reason even if you don't need them for 3d printing.

[@earringtherapy]

It worked, thanks. Nam

[@notverygoodguy]

@@earringtherapy Thanks for letting me know!

[@unloadedsushi]

when I use the displace modifier, the model inflates either way, positive or negative. Maybe this is a problem with a new blender but im not sure. What is happening?

[@unloadedsushi]

it dosent get skinny like in the video

[@notverygoodguy]

@@unloadedsushi You do have to be very gentle with the slider. Perhaps holding SHIFT while you do it will give more control. If not could you provide a link to your blend file. I may be able to take a look.

[@babbagebrassworks4278]

Saw a guy add a blue LED to his 3D printed figure, I immediately ordered some warm whites 0402 leds with wires for my gas street lamp models. Now I have a clue how to hollow them out. If your figures are printed from a flex resin wires could be inserted to make it pose-able?

[@notverygoodguy]

When I have added wires into 3d models I have found a good approach is to actually model a pipe or something that goes right through the model so wires can follow the rout of the pipe. This pipe has to be modeled so that the slicer doesn't actually just remove it but for me this has worked well. I have a model of a lady holding a flower to her nose and the flower has an led in it. To do that I modeled a pipe from the flower, through her finger, down her arm, into the body and down to the base. This made it much easier to thread wires through :) This gives me an idea for a video though :)

[@mestevep12]

Thanks, allways wondered if this was possible...is there an easy way to view cross sections of your model ??

[@notverygoodguy]

Here you go. My shortest video ever. How to do a cross section in Blender :) kzbin.info/www/bejne/iXi6Z5mjramcfLs

[@jimmiller6004]

Don’t you have to close up the now non-manifold holes created by deleting the hands and feet? How do you deal with self-intersecting surfaces that can occur in tight corners?

[@notverygoodguy]

You could do that and the 3d print plugin is great for it but the slicer fixes it every time. The model is still manifold on the outside of course. Maybe there should be a small warning that there could possibly be problems but I haven't seen them yet. The point here is to avoid doing the hollowing at all on tight corners so if they are not part of your "hollowing" vertex groups they won't be hollowed and no intersections occur.

[@EdgarCaballero]

hi, how do you do that on your head, hands, and feet?

[@notverygoodguy]

The point here is that the hands and feet are too small for this to work reliably but in any case you don't need them hollow for resin printing because they are small enough to not need hollowing anyway. For the head, you could just select the head when selecting the rest of the body for hollowing as show near the start of the video. Some thought needs to go into what you are selecting though. For example, ears probably shouldn't be hollowed or anything else that is very thin. The good part is that if your displacement doesn't look right you can add and remove selections from the vertex group to fix it up. I may do a follow up video for things like that.

[@EdgarCaballero]

@@notverygoodguy Sorry, I understand, my real question is how do you prevent the face and hands from being deformed with solidify, do you have a video, thank you

[@notverygoodguy]

@@EdgarCaballero Do you mean how do you do it with the solidify modifier instead of using this method here with the displacement? If so, you can sometimes get it to work my changing the mode of the solidify modifier from simple to complex and playing a lot with the settings. I was going to do a video of that when I thought of this way of doing it with displacement :)

[@EdgarCaballero]

@@notverygoodguy Yes, that's exactly what I'm looking for how to handle solidify in small details without deforming the details.

[@notverygoodguy]

@@EdgarCaballero I think this displacement method is better than using solidify actually. The end result is the same but you are able to model the shape of the hollow. Remember also that for really small detail there is no real need to have it hollow. Anyway, following a quick poll on my community page I've decided that the next video will go into this in much more detail and showing how we can handle complex cases. Maybe it will help :)

[@marcelodeniz3932]

Exist methods much better this

[@notverygoodguy]

Would be great if you could show a link to them so we could all perhaps learn something.

[@marcelodeniz3932]

@@notverygoodguy I will go make this video showing the better way for make thickness and holes for 3d print

[@notverygoodguy]

@@marcelodeniz3932 Thanks and please share the link when it's done. I am always excited to learn new tricks :)