Printing hollowed model

Just want to ask for advise on how to print this one. I’m trying to print a model with hollowed base. see pictures below. Any advise?

Here is the link of the file:

https://drive.google.com/open?id=0B-ZF4oQEM8I4TFZTV1BVRVFUQ2c

I thin this file won´t print. there are a lot of hollow regions and some regions of this model are inside out. do you have the original .stl or obj. file?
Use meshmixer. Or do you have another software? If the surfaces are grouped it would be easy to remove all existing holes and the insides of the hollows. Separate shells if possible. Try to unify (boolean) all parts into one and hollow the resulting model. It should be just one shell in the end. Do not forget little holes to let the air flow.

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I would invert it, too much cleanup on the teeth, but Klaus is right, you’ll have a mess with all those cavities, you need to make it a solid first, then hollow it, or shell it with an open back.

How did you hollow this out? You want the interior to be one single cavity. And for the best probability of successful printing, the end of the cavity nearest the built platform should be “vented”, there needs to be a breather hole so when the open end of the print is plunged in to the resin for the next layer, the pressure buildup inside the cavity can vent out those holes.

I agree with JRStudioBoss, too. Flip it over so the supports are on the base and you won’t have to do any final cleanup/finishing of the teeth after removing the supports.

Thanks guys,

I actually printed it long time ago, and you are all right. The teeth part was a mess. What I’ve done on the meshmixer was:

  1. Make a square base, then I hollow it.
  2. Then create the arc part of the base and unite it in the square base.
  3. Put the teeth model on the base.

So the result is that. I guess what the steps I’ve done is wrong. Thanks for suggesting. I don’t have the original stl file for this so I guess I’ll remake this one.

I’m new to meshmixer so combining parts is hard for me. Any suggestion on what tool to use in the meshmixer so I can make the model parts as one and hollow it perfectly? Thanks.

I tried using the boolean union, Is it normal that the edges of shapes change like this?

You should remesh the box or the meshes. (select the object - press “s” press “ctrl (cmd) + a” (select all) in the selection window select “edit” and then remesh. A new window pops up and here set the remesh mode to “target edge length” then you can define a edge length that is good the object - you have to play around with the settings.
Hollowing the object is always the last step. First remesh if necessary than boolean and the last step is to hollow the object.
I attache some screenshots.

I print models like this all day, every day.

I just put the flat edge on the back of the model flat onto the platform.

Curious why you didn’t print with the flat side having the supports instead of the detail side? Personally I try to use the smoother sides for supports so clean up is easier.

@KlausLeitl

Thanks. I’ll definitely try this out.

@Smilelign

Thanks. Do you have premade base for your models?

@KenCitron

I’ll already tried it, the model produced was failed so I thought orientation was the cause. But next time I’ll put the support on the flat side. Thanks

I used the supports within PreForm. Find it easier to monkey around within the output software than make that extra back and forth. PreForm has some pretty accurate warnings built in.
I do like the hollow feature in meshmixer. Pretty handy on sculptures.
i
Usually as a rule of thumb you angle at roughly 45 depending on models shape with the least detail side with the supports and bulk of the model towards the build platform. Angles reduce forces and tearing, least detailed side is easier cleanup and bulk of the model towards build platform reduces stress as the model is built.

@spms_jomar

We base all the models in either 3shape or maestro. I then load them into magics, hollow the model and punch a hole in the base to allow the resin to flow out. We print them out with no supports and they come out perfect. Sometimes its a bitch to get them off the platform but thats the only real issue

@KenCitron

yeah. I print usually at 45 degrees on some of my prints, too.

@Smilelign

For now, I’m creating base models manually. I guess we need to buy intraoral scanners if we want better results.

Thank you guys for all your advice.

I don’t know the dental process but wonder if you could take the usual impression and scan that in? Might give you a descent point cloud to work from no?

@KenCitron

Some of our prints are from usual impression and we scan it using CBCT Scanners. Then we do the reversing process of it in th Blue Sky Plan to produce model. Other prints are from the DICOM files of patients, model generated from The Blue Sky Plan Software.