Making some good progress on my model. I'm hoping to output the STL file for RP printing next week.

I am also *finally* getting used to "just typing numbers in" for numeric input. LOL

Cheers,

Chris

My RP guy is getting odd translation errors from my IGS file conversion. Any ideas? I turned up the polygon level to its highest setting when I did the output/conversion.

Thanks

Chris

Hi Chris, above you wrote "IGS" file conversion - did you mean STL conversion?

Normally to get a clean STL file generated, you should have just a single solid object that you are exporting.

In your case you don't have that - instead your model is made up of 11 different individual objects, note the readout after a "Select All" here:



Also if you look in the scene browser, you can see that you have at least one object that is an open surface instead of a solid:




You can use the scene browser to select that open surface object by clicking on the text for "Surface" there, that identifies this part as the one that is not a solid:



Then running the script from here which selects naked edges, identifies these edges as being open and not attached to anything else:




So to remedy that, select that crossbar piece and then run the Construct > Planar command, which will fill in the open end with a trimmed planar surface and seal it off.

Once you have done that, you will then have 11 solids in the file.

It may possibly work at that point, for some cases it may be ok to have multiple solids within a single STL file but really the main original intent for an STL file is that it should contain just 1 single solid in it and not multiple ones.

So then you would probably want to use boolean union to combine those multiple solids together where they are touching so you only have just 1 solid. That's what I've done with the attached updated 3DM file.

The attached file is now all ready to be exported to a good STL file.

- Michael

Michael, I'm on the run today but I wanted to say THANK YOU for your help. I will post photos of the RP output next week.

C.

Michael, is the "scene browser" available in the demo version? Did I miss it? LOL

Thanks

Chris

Hi Chris,

> Michael, is the "scene browser" available in the demo version?

No, it's available in the v2 beta - the demo version is v1 and doesn't have it.

There are a whole lot of improvements like this in v2, v1 is actually about 2 years old at this point.

I've just recently released the final v2 beta - next I will be updating the documentation and after that is done then v2 will be released and at that point I will update the demo version to be a v2 demo instead of the current v1 demo.

- Michael

Yes, I started with V1, and thought it was pretty good.

V2, however, is fantastic :)

Hi Michael. My 3D model got bounced once again by the RP house for not being watertight. Any suggestions? I've run the "find naked edges" script, but have been unable to repair the model. Can you guide me through this?

Thanks

Chris

Hi Chris, well there are going to be several steps involved.

Even apart from having some holes in the bottom part (84 naked edges) you've also got your model set up as various separate solid pieces instead of just one single solid which is what those RP things want to have.

For example you've got 1 object here which is a solid:



But then right next to it you have this completely separate object which is another solid:



You generally want to combine things like that together into just one single solid, probably by doing a boolean union on them.


The openings look like you have some surfaces in place ready to be joined in to seal them up. Like for example this part has some openings in it:



However, you've already created some surfaces that fit in at least some of the openings, these are some separate surfaces that are hanging out just right in that spot:




You need to use the Edit > Join command to glue those separate objects like that together so that they will be connected at a joined edge, rather than just having completely individual separate surfaces that are just positioned next to one another.

The actual joined connection is what you need there.


I haven't had a chance to look at all the different holes in that lower part, but if they're all like that then you just need to join those pieces together in order to make closed solids from them, then probably do boolean union between those solids to make the whole thing just 1 big solid instead of a bunch of different separate objects.


Does that make sense for what needs to be done to fix it up?

- Michael

Hi Chris, here's an example of another piece that needs to be finished - this is one part from the bottom, as you can see i't missing some planes from it, those need to be created and joined to this piece to make it a closed shape right now it just has some totally open spots:




- Michael

Also a few pieces are not touching and will need to be moved slightly, for example here notice these parts are actually floating a bit away from the other surfaces instead of touching them:



- Michael

Hi Chris, it should actually not take much work to get this finished, I've got it nearly all cleaned up but I'm heading out for a while, I can probably finish it for you later.

- Michael

WAH! Thanks for taking the time to point these errors out to me Michael.

If you don't mind fixing it, I don't mind the helping hand! LOL

C.

Hey Chris, don't take this the wrong way, you should try and fix this yourself for the experience.
Some might pick up nurbs modeling very quickly, but it takes longer and more experience to know why something isn't working and the best strategy to fix it. Micheal has already pin pointed a lot of areas so you have a good head start.
It will make things easier and quicker in the long run, if you get stuck the forum is always here to help :)

Cheers and good luck.

Hi Chris, I've attached a finished up version, I think this should be ready to send out as an STL now.

One of the key things that you want to look at when you're preparing something for STL is the object type indicator - that's the label in the upper right area of the window which shows some information about the selected objects.

You want to periodically check that indicator to see if the selected object is a solid or not, and also how many different objects are selected. Do a Ctrl+A to select everything and then look over here:




Your goal for making an STL is to make that readout show that everything that was selected by Ctrl+A was just a single solid. In your previous model, if you do that you can see it says "49 objects", which means you've got a bunch of different pieces and some are solids and some are open surfaces.

So to clean things up, I started by selecting some of the large top pieces that were solids and using boolean union to combine them together into larger pieces.

Then another key thing is make sure to hide pieces if they are getting in your way, otherwise it can be difficult to see if there are holes or things when you have other pieces sitting right on top of what you are trying to work on.

Once I got all the big pieces booleaned together into one large unit, I hid that and then started to look at the bottom parts, those were the areas that needed some planes to be drawn in and joined in to finish off some parts. Then that was followed with some more boolean unions between parts to keep on combining parts together.


But try to keep track of that type indicator, that will help you to know if the thing you are currently working on is a finished and closed up solid or if it still needs some pieces to be joined into it.

I hope this helps!

- Michael

If you create an object only for a photo is very different than if you create it for a 3D printer or other machine...
Sometime it is not the same way to work.
Don't change your design in order to resolve the errors.
Try, try and try again.
Good work

Fil

Hi all... So this model got bounced again by the RP house for being "non manifold", or not water tight. Very odd!

All I did was scale the model that Michael fixed by .044 to give me the correct model size, and then output the STL with approx. 400k polygons.

Any thoughts?

Cheers,

Chris

Hi Chris, what meshing parameters were you using to generate the STL file?

I did actually test generating an STL file from the model I posted, and it read into Rhino and verified that it read as a completely closed mesh.

But maybe some particular meshing parameters that you are using is creating some problem in the mesh, it could be that you are getting some areas with too many vertices being packed together, making the RP house's analysis tools think that they are all lumped together instead of being distinct. If that's the case then you may need to make a somewhat slightly looser mesh instead of an overly dense one.

It's hard to know exactly what you are running into though without some very specific information - please post your scaled model file and also give me the exact parameters that you are using for producing the STL file, that way I can generate the same STL file over here and examine it closely to see what might be going wrong.

- Michael

Hi Chris, it's also possible that you have created some details in this part which are just too small in relation to the resolution that the RP process can actually handle, like for instance here:






That's a little tiny fillet piece with a radius of 0.06, and that's actually from your previous model before any scaling down.

If you're then scaling down by a factor of 0.044, that's going to make that particular feature have a radius of 0.00264 , which is extremely small, probably quite a long ways beneath the actual resolution of what their RP process can produce.

Then since it is a curved surface it will get a bunch of smaller polygons generated in that area as well.


Such small features may be considered by their analysis software as being essentially collapsed together, which can confuse the analysis of the volume. If that's the case then it could be possible for them to adjust the tolerance being used in their analysis software to reduce it so that those things won't be considered to be lumped together. But it is also possible that you may need to eliminate these tiny features or possibly not use a tight angle value when meshing, to avoid this kind of problem of generating micro polygons that are smaller than what the RP house is expecting.

- Michael

Hi Michael. I guess this is why modeling full size and scaling down for output is a bad idea. LOL

This has been quite the learning experience.

C.