Help me make these printable


#1

I’ve been making a few designs of these security desks for an art project, and I’m having trouble making them printable. I didn’t realize that the best way to print was to make a hollow design with a few millimetres of wall thickness, and now that I’ve made some fairly complex designs I can’t figure out a way to add thickness to them. I’ve tried JointPushPull, MakePrintable, and even putting the file into Blender and adding the solidify modifier. Any time I try these crazy shapes start emerging all over the place. It seems like there should be a pretty simple solution, but I can’t find anything beyond just starting over again.

desk5.skp (272.9 KB)
Here’s just one of many designs.


#3

Neatness is an essential aspect of building a printable or “Solid” 3D model.
The model you shared would become a Solid if you were to clean it up by erasing the myriad of stray edges you’ve left behind and all unnecessary interior faces.

The interior doesn’t need to mirror every detail of the exterior.
That is, modeling a slightly smaller simplified version of just the major features would suffice in reducing the amount of print material required down to a reasonable level.

Here’s what you’re trying to accomplish and a few tools that you’ll find helpful in the process.


A Solid in SketchUp is a single Group or Component whose geometry meets certain conditions.
When those conditions are met, Entity Info indicates the model is a Solid Group or Solid Component.
Also notice Entity Info indicates the Volume of a selected Solid.

• The geometry must form a single* airtight vessel.
Like a perfect soap bubble … •No gaps •No holes •No leaks

• No extraneous Faces** inside or outside the vessel.
All Faces must serve to enclose the singular volume of the vessel.

• No stray Edges.
All Edges must serve to support a Face that in turn serves to enclose the airtight vessel.
Thus, each Edge supports two Faces … no more, no less.

• No nested Groups or Components.

*A Solid Group or Solid Component may contain one or more separate airtight vessels.
**Best that all Faces are oriented Front Side (white) facing out.

Understanding Solid Objects in SketchUp — Aidan Chopra
http://www.dummies.com/how-to/content/understanding-solid-objects-in-google-sketchup-8.html
http://www.aidanchopra.com/web-content/chapter-6/understanding-solids

Solid Inspection/Repair Tools

TIG: SolidSolver
http://sketchucation.com/pluginstore?pln=TIG_solidsolver

ThomThom: Solid Inspector²
http://extensions.sketchup.com/en/content/solid-inspector²


#4

Bret: Thickness is not necessary for model to be solid. For say a simple small cube without added wall thickness the slicing program used by the printer will assume the total vol is filled with material thus drastically increasing the amount used to print it which can increase material and print cost ~10 x ( if commercial printer does print).
There many other considerations you need to factor into the model you design. .
FYI
http://3dprintingindustry.com/3d-printing-basics-free-beginners-guide/processes/
https://i.materialise.com/blog/3d-printing-with-sketchup/
https://i.materialise.com/learn/file-optimization-guide. Note other printers also have similar free service. These folks on this link have working relationship with SU.
BTW I assume you have school printer to use and the model size they can print will be small so keep that in mind while fixing your model


#5

Brett: do not think you need to redraw completely. Suggest the following:
1 Rescale to some reasonable dim like 12" ;
2 Make component of top of “spire” and desk top and hide;
3. Make some construction line references for future use to re-assemble later and then delete desk body down to plan view and then use offset tool to make a wall ~5mm thick;
4 Pull wall to guide line refs points
5 Repeat same type sequence for desk top after hiding desk body.
6 Simplify the sipres
Component geometry in SU does not stick together so as you go check each for solidness. To combine into one solid model and that will require some clean up to make solid again.
Some steps like this hopefully avoids complete redraw


#6

Yeah the techs at my school are trying to help me out with this, it will print fine as a solid object, only its gonna cost a couple hundred bucks each, even when scaled down to about 6 inches wide. We’re trying to figure out a way to make it hollow and thus cheaper. I’ve tried alot of these services and the school’s own software and they all seem to warp and start making weird faces pop out of nowhere. I’ll try following your steps and see what happens.


#7

Suggest for time expediency you use the service of several the commercial printers. They have free links where they fix your model if it can be fixed. Try imaterialise ref link I gave above and shapeway has a cloud based service also. I’ll find the link for you http://www.shapeways.com/tutorials/how_to_use_meshlab_and_netfabb.
there is a repair paragraph in that shpeways link for their cloud baesd repair service.
Note that SU has probllems with geometry in the range of .001" and I ran into that when tinkering with you models. You may have to scale up to say 500" wide to avoid that issue but make sure the wall thickness accounts for fact you will be scaling down, the final wall thickness should probably be in the range of 5-10 mm. Aslo note the model must be a component to be solid and your op post was not.
The printer your school has may impact model requirements because the printer usually has a built in slicer program that slices you model into thin layers . There are other issues with you model usually called over hangs. The printer probably heats plastic to extrude thru a high tech " glue" gun and until that cools down it can be subject to “flow”. Where the “desk” over hangs maybe a problem I have not yet looked at that issue. The general rule of thumb is 40 deg angle fro firm base to that type of entity is limit.
Check MeshMixer it accounts for some of these issues in its analysis


#8

So… I basically just redrew it, using the original as a guide. This should work right? Took a while to do, now I just gotta do the same for the other 10…

desk5SOLID.skp (1.2 MB)


#9

Entity info does not report as solid but solid inspector reports 4 nested instances. Su will export to STL ok per ThomThom.
What the printer says will tell.
What printer are you using, commercial or school? If schools can you say what it is??


#10

There must be some small errors in the components because they are not showing as solid with a volume in the entity info window.
In the case of the top there is a tiny line preventing it from being a solid.
See below,

Shep

In the base, there are two lines that are connected to more than two faces. If this situation is corrected the base will become a solid as well.


#11

Since you have more to do get plugin “stray lines”, using that corrected the top in mins and shows solid now, base is another issue solid inspector reports numerous short lines, scaling up then back down may help.:slight_smile:
Good luck, nice redraw
http://www.smustard.com/script/StrayLines


#12

Scaled model up to 500 " and there are still 347 tiny edges , hope a batch correction approach can be found: sweat:
simpler base but solid, more worked required still many ~ 90 tiny edges
desk5_simple base.skp (56.4 KB)


#13

So I did a test print on the school’s ZPrinter 650, seems to be ok although I chipped off some pieces in the excavation. Probably gonna scale things up about 30% to make it stronger.