Models printing with hollow spaces and gaps

[Milestone85]

I have tried several models which I've used with different software for the Afinia and up mini 3d printers which print fine... But when I slice them in s3d some models have gaps for instance I have a sledge hammer model which should print solid and connected but in s3d the shaft has a gap when connecting to the head. The parts easily break and would require glue to put he shaft in the hole left in the head of the sledge. Similar models like a bench grinder prints with hollow parts inside when using 15% infill or any infill for that matter. I have another pick axe model which prints with a gap between shaft and pick head as well... I never had these problems with other software. Perhaps there's a setting that can solve these issues ? I want the models to print as a whole with 10-30% infill, And not fall part when I pull them from the print bed. Thanks in advance.


Www.topshelfhobby.com for model examples I am trying to print.

[jimc]

can you post the stl files please?

[Milestone85]

Heres sledge

Sledge_long.stl

Sledge Model

(1007.09 KiB) Downloaded 689 times

and here's the grinder model Check out the inside of the grinder it seems hollow but has a shaft going through it.

Bench Grinder Fixed TSH.STL

Grinder Model

(2.46 MiB) Downloaded 566 times

Also here is another model I have problems with (but not in other software just S3D perhaps im missing a setting or the model needs repairs in S3D?)
You will notice the handle has a gap which does not bond to model, model prints and I have to manually glue handle on, again before I didn't have to do this.

Chainsaw Body with TSH logo.stl

Chainsaw body

(1.93 MiB) Downloaded 571 times

thanks

[Festus440]

They have multiple meshes.
Go to the '"Advanced" tab and turn on "Merge all outlines into a single solid model".

[Milestone85]

Thank you so much I will do this now!

[Milestone85]

Hi I tried that but it still the same... Perhaps I will have to get the models with errors all edited so they are one solid mesh?

Is there anything else I can try that you are aware of.

Here is the simulated print, as u can see its still hollow inside head of sledge... and a gap from sledge head to shaft.

[Festus440]

You might want to try moving the part or rotating it.
That shouldn't make any difference, but apparently it can.
Here is rotated 45 degrees.

But here is at 90 degrees:

Just moving it around a little seems to change how it slices slightly also.

Seems like a bug to me. (But of course mainly due to the model having the multiple meshes.)

[jimc]

yes there is a bug with things like this. s3d in the past relese is sensitive to errors in the model. it will pickup things that slip right through netfabb and cause a problem with slicing. leave the model where it is and adjust the first layer height a little. go up or down 1% at a time and see what happens. you should run the model through netfabb anyway to be sure it is error free and also put it back in your cad software and merge it into one solid model.

[Toby]

I was able to get the sledge hammer to work by orienting it vertically with the hammer end down and slicing with the "Merge all outlines" box checked. Here's a pic just before the handle would start to print.

sledge.JPG (16.66 KiB) Viewed 10854 times

Not sure if printing that way would be a problem, but offhand it seems ok to me.
In general it's true S3D doesn't like objects made to appear solid by juxtaposing two meshes. If you have access to booleans that would be one way to clean it up.

[Toby]

I just remembered another way I've gotten this sort of thing to work: When you model an object as two or more meshes merged together, save them all as separate objects and load them into S3D one at a time. Apparently when it knows the meshes are separate objects it's smarter about figuring out that the overlap isn't hollow.