How to cut up and key a hollow model in Blender for 3d printing

[@g0balot]

Thanks. So much easier than trying to close the hollow gap manually

[@notverygoodguy]

You're welcome!

[@xavierplasencia8065]

Excellent tutorials, by far the best on splitting models I've seen. Clear explanation, easy to follow and great results.

[@notverygoodguy]

So glad to hear this! Thanks for the feedback.

[@06madmartin]

this is very useful info though a real dirty way is to just use banana split plugin in cura slicer drag your model half way into the build plate a hit cut and boom a cut model for u to more easily print tho keying them is another thing entirely. u can export it as 3mf and use an online converter like swift to convert it back to a file blender lkes and key them

[@notverygoodguy]

With a hollow model though you will still need to fill up the hole.

[@kimlindaberrystudiollc9403]

Very good explanation. Question though, couldn't you first cut a solid model in half and then hollow out each half? Wouldn't that achieve the same basic result?

[@notverygoodguy]

To be fair, this video was aimed at cutting up a model that was already hollow :)

[@vampvesslim3871]

very clear explanation, thank you.

[@notverygoodguy]

Appreciated! Thank you.

[@kolhoznik5]

very nice. thanks

[@andrewdowney760]

Hello, just downloaded blender and watched your vid. Ty ty Could you do a tutorial on dovetail joints please? I have a model Id like to split in half and be held together by a top third piece using a dovetail join. Thanks for your time

[@andrewdowney760]

I checked and there are NO tutorials for blender dovetail cuts. There are some for fusion 360

[@notverygoodguy]

Interesting idea. All you would really need to change from this video though is to add a dovetail shape to the "cutting" plane. An easy way to do this would be to take the plane and simply create two loop cuts down the middle of it. Select the faces inside the loop cuts and pull them up a bit (with the "g" key) at 90 degrees to the plane (probably the Z axis locally to the plane). Then scale the already selected faces on the local x or Y axis to make the inverted triangle shape of the dovetail.

[@liyueyuan5888]

how can i cut up a model with the 1 wall and a inner tube? i can't get that to work i also tried to follow you other videos where you cut up things and it wont work.

[@notverygoodguy]

I am not sure what you mean can you post a picture of your problem somewhere? Maybe in the Blender for 3d printing facebook group or some other way?

[@obi-onekenerdi]

My only problem is my model doesn’t have a rim, the outside and inside faces are just the opposite sides of each other.

[@notverygoodguy]

If that is the case then your model isn't hollow. Perhaps a video on cutting up and keying a normal model would be more useful for you :) kzbin.info/www/bejne/oGbEpWWuZaiWjpo

[@playerone6373]

would there be issues if i just slice them and leave the walls as is? esp for small action figures? what i usually do is cut it from the neck, trunk (sometimes include limbs) then waist to legs. so thats either 3 or 5 parts, since there would be holes i am just filling it in to close it then ill be using those to be the key and hole, i ran out of resin and still waiting for it to arrive, do you think itll work?

[@notverygoodguy]

If you slice a hollow model into parts, blender (and most other software) won't fill in the bit where the hollow is so you will be left with parts that have just the walls. You COULD just fill the gaps in yourself but that can get messy especially if you are using an STL with geometry all over the place. Also you are also likely to make a zero width face which won't print. I should have shown an example of this in the video to clearly show what happens if you just slice a hollow model as you would a solid model. This is why I did this video and used this technique which I might add, I was rather pleased with :) Try it and see what happens. You don't need to print the result to see the issue.

[@apsjongz9931]

Does the wall natter once cleaned through 3d builder? I mean its an auto hollow app. Im just worried that if i attached a peg and the wall might collapsed since it is too thin then i realized i never tweaked any and just used 3d builder to hollow and then choose wall thickness in lychee and it seems working but havent tried with cutting joints and adding a peg

[@notverygoodguy]

The wall thickness where the slice is is up to you. You just adjust the size of the "cutting plane" to suit when doing the inside cut. I probably made it unnecessarily large in this video. If you chose say a 2mm wall thickness when hollowing in Lychee then I guess using a 4mm thick cutting plane would give you a 2mm wall thickness at the cut. However, you would have to have a "key" and hole that was small enough not to cut through the wall. I think a 1mm thickness for the hole wall would be OK because you are likely gluing the model together at that point anyway. Hope this makes sense :)

[@apsjongz9931]

@@notverygoodguy yeah i was using plastic cement to glue them together but i guess what im looking for rn is some sort of a snap build with enough friction to hold the pieces together.

[@notverygoodguy]

@@apsjongz9931 This is not the way to achieve that. It is also unlikely to work with resin. If you are doing FDM printing you need to engineer mechanisms for clipping together as the tolerances are not reliable enough for a good friction fit.

[@elisehounslow6572]

but I don't have the inside, how do I make that

[@notverygoodguy]

This video is specifically for hollow models. If you don't have a hollow model you could try this video instead kzbin.info/www/bejne/oGbEpWWuZaiWjpo

[@yahyaalnahdi7216]

No plz have mercy on him 💔💔💔💔

[@9words40]

y would u do that to him xD

[@notverygoodguy]

To get more food in perhaps :)

[@Kommander_Rahnn]

I want to keep the hole. How do I do that?

[@notverygoodguy]

Which hole do you mean? The hole created that matches the "key" shouldn't go away.

[@Kommander_Rahnn]

@@notverygoodguy when I split the hollow model. I want the openings to stay.

[@notverygoodguy]

@@Kommander_Rahnn Oh I see. If your model starts out hollow like in this video then you would only need to create the plane as shown in this video and do the boolean. No need to separate the inside from the outside and no need to do a boolean on the inside of the model too. If your model isn't already hollow you will need to make it hollow first. If your model is quite simple then you would just add a solidify modifier to it. If it is complex that might work or you might just hollow it out in your slicer and export the result as an stl for Blender and then cut it.

[@Kommander_Rahnn]

@@notverygoodguy Awesome. Thanks for your help.