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not so tight models...

    
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smd

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Message 1 of 22

 not so tight models...
05-11-2009 02:01 . pm   |   View his/her posts only
Can anyone recommend a better a better build strategy to avoid this. Here are two models. they export as solids, but when viewing in solidview, you can see a lot of exposed edges, and when i print them, they show these weak points. However, the five sided model is much better than the four sides, though they're both modeled the same way....any suggestions? Scott

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Mike

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Message 2 of 22

05-11-2009 02:16 . pm   |   View his/her posts only
Scott,

I would need a VX file in order to comment.

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Paul

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Message 3 of 22

05-11-2009 02:51 . pm   |   View his/her posts only
Hi Scott,
Looks like all the open edges are on the text inlay edges.

What did you do in the way of ensuring there a no gaps in the font curves used for the text?
When you inquire/show gaps in those sketches do you get a clean result?

Fonts are not always clean even though VX extrudes them. Common problems are gaps and overlaps and non tangent curves.
Concatenation of font curves, merging of overlapping lines etc. often worth a try.
If the profiles are not clean this should show up in wire frame.
If not obvious there, I check for edges etc using the Heal/Analyse Topology and try and get a handle on what is causing theme to appear.
You can step through and analyse after each relevant history line and find out what is the originating problem feature then look at resolving this. A clean model should export OK but read Chris's comments re STL Rapid Prototyping.
Cheers

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Robert

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Message 4 of 22

05-11-2009 03:03 . pm   |   View his/her posts only
Hi Scott,

Since these are tiny parts, you may need to crank down the default tolerance (Edit->Preferences->Tolerance). The default is set to .01mm and this may not be small enough for your little parts (no pun intended).

bobf

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smd

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Message 5 of 22

05-11-2009 06:32 . pm   |   View his/her posts only
Whoops, thought i put the vx and stls...sorry. Inquire show gaps is clean on all sketches and the tolerance is at .001. the real problem in the printed parts in on the four sided model on the inside edges of the offset faces..the border on the edges of the blocks has gaps so there lifting away when printing....i can fix the prototype, but am curious as the five sided doesn't exhibit this problem...here's the vx files mike

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Paul

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Message 6 of 22

06-11-2009 01:54 . pm   |   View his/her posts only
Hi Scott,
this is an interesting model 'cos you used quite number of good tools.
No gaps or overlaps and your model reports error free which is good work.
I looked at the curves you used for text.
Not sure where they are coming from but while they are contiguous, they are not particularly tangent or smooth.
In fact I would describe them as a bit ugly.
IMO VX does a great job of the morph all things considered.

I would be smoothing all the text to eliminate these continuity abberations then seeing if this resolves the problem.
Doing this in VX is a bit clumsy as curve editing is not as easy as in say Corel Draw or other vector programs.

It is also possible to radically simplify the construction of the base. Can do a simplified version if you are interested.
Cheers

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smd

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Message 7 of 22

10-11-2009 10:04 . am   |   View his/her posts only
Thanx for the input. But the real problem in the printed parts is the outer trims....they're not attatched fully. The text reliefs haven't posed a problem in any prints yet. But am wondreing why the difference between the two similarly made models? I could probably remake from scratch and get a differing result? How could this base be constructed more simply that lofting the shape, offsetting faces, then twisting/morphing....usually the answer comes to me before I finish asking the question, but not this time. Scott

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ChrisWard2k2

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Message 8 of 22

10-11-2009 01:00 . pm   |   View his/her posts only
Hi Scott

One tip would be to define the model at a larger scale (say 10x), scaling the geometry down to the required size as the last History Operation. This may help the computations because the tail-end of long floating point values can be 'lost' by the processor, introducing inaccuracy.

Mudcrab is correct when he suggests that text inlay could cause issues. When any new feature is added/subtracted from the model, all faces affected are re-sewn by the modeler - so in fact the new faces introduced by the inlay could be sound but existing faces might be disturbed in the process. For example, the 'host' face that the inlay is cut from may need to become two or more faces and/or generate a tiny 'slither' face that is very close to the computational tolerance (which, re my first note, means that it could fall in and out of tolerance on regen).

Now, checking your model with the VX Heal analysis does not reveal obvious problems. SolidView highlights a lot of the edges as 'wrong faces' (on both 4-sided and 5-sided STL files), if you zoom-in and study them, render mode Shade + Triangle Edges, the mesh looks good but indeed there are very thin triangles along the edges and this could be an issue for your printer. Are there temperature tweaks that can be made to get a better material fusion? I saw that mentioned by a Solidscape customer on their website. The orientation of the model may also make a difference. I can see that the printing will be fast as you have the model now, but there could be slices that equate to very little material.



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Mike

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Message 9 of 22

10-11-2009 02:04 . pm   |   View his/her posts only
Scott,

Besides possibly creating the final loft lines with some math and using them for the loft. This would eliminate the morph all together. The two features that add complexity to the model are the morph and the inlays.
Take a look at the technique used here for the inlays. Pay attention to the concatenate commands after the sketches are projected to the surface. It reduced the number of edges. Let me know what you think.

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Paul

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Message 10 of 22

11-11-2009 02:49 . am   |   View his/her posts only
Hi Mike and Chris et al,
I submit a simplified version of the bead.
Sans text and morph I get a an error free STL by Minimagics test.
Sans text after morph I get errors. Edges and shells???
Curious stuff.

Scott, I have learnt a lot from this, especially morphing.
Got to know which tweaks to do eh!
Morphing is still mystical for me.
Would really love to see a decent demo training video with full explanatory audio on VX morphing variants.

History shows a different way to do the job.
FYI I have concantenated the text sketches but not sure if this is helpful.
I have used an equation set as a demo of how you might reduce the remodeling for variants.
You can do a lot more if you want, this was a 'quick' job.

An issue I found V13.75, is that I cannot redfine the morph points at all.

I hope it is of benefit to someone.
Cheers


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John

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Message 11 of 22

12-11-2009 01:52 . pm   |   View his/her posts only
I saw this post became interested in the various methods of creating it. Thought I would submit my own version eliminating all the morphs, except the last one. I also wanted to showcase the application of the wrap command. I do agree the lettering sketches could use some work. I think coupled with the equation set proposed by Paul this could be a very powerful model.

John

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smd

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Message 12 of 22

12-11-2009 11:42 . pm   |   View his/her posts only
Thanx for all the input folks. Guess there's more than one way to skin a cat eh? Thanx Mike for the help with the install. And the files. Paul, your input helped, but i couldn't open your file? Thanx John, used your wrapping and inlaying. So here it is with out any morphs and those pesky open edges appear to be gone on the inside of the outer trims where it was posin a problem. Still lots other stuff in solidview, but we'll see if it prints. So morphing crates these issues, Too bad, as it's a powerful tool. However if one was milling and just followin tool paths I suppose lots of this wouldn't be an issue.

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Randy

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Message 13 of 22

13-11-2009 12:37 . pm   |   View his/her posts only
Wow! Morphing, Wrapping, Inlay, this thread has had some pretty useful stuff at least for me.

How ironic to learn this much about the use of morphs from a part that ultimately ended up without any.

I agree with Paul that it would be nice to have the mysteries of morphing better explained in a downloadable tutorial.

Randy

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smd

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Message 14 of 22

13-11-2009 05:51 . pm   |   View his/her posts only
Funny, the morph tools , well curve to curve and with point, i've used quite a bit in my modeling, but i've always outsourced prototyping and wasn't aware of problems. I recently aquired a 3d printer and all hell broke loose now i gotta clean up my modeling so i don't have to spend big bucks on repair soft! It's very useful being able to see other folks stratageys on the same project. I've learned quite a bit in this session....being a jewelry modeler i spend a lot of time over at 3dcadjewelry.com, where they use all sorts of different softs, the primarys being artcam and rhino. Even there though you tend to learn new ways to approach jobs. Different thought processes.I'll post some pics of this model when it done allong with the ones that weren't working.....

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Paul

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Message 15 of 22

14-11-2009 12:14 . am   |   View his/her posts only
Hi Scott,
surprised you cannot open my file. I have downloaded and it runs fine. It is V13.75. There is an issue with the wrong face being selected on regen sometimes for the first face offset. If it falls apart on regen this is the culprit. This a VX quirk. I suggest you download again as there is more cat skin there.

John, I had a look at your text sketches. Very nice work. I tried concatenating with various ottions (tengentm, curvature etc.) 'cos I think there is room for refinement in the smoothness of the text. I am not sure what the problem is but this seems to change the way it works and IMO it shouldn't. Some concatenations (V14.20) actually deleted lines! More importantly, I was mesmerised by the wrap command - just hadn't realised that was possible. Yet another area where the VX WIKI needs a major audio visual boost exploring all the variations.

Randy, I chuckled when I read your comments. Makes you think that VX is really undersold even to old hands. I think the lessons of this thread would be so cool if the models etc where available on the Wiki with relevant comments etc. e.g go to Wrap Text Help and see a quick video(step thru of how the wrap to face was done with a few comments long the way. All very fascinating.

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John

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Message 16 of 22

14-11-2009 06:43 . am   |   View his/her posts only
Hi Paul,
Thanks for the comments. I use the wrap command in the other Cad progams we use and when I considered VX it wasn't there. I talked with Bob prior to purchasing VX, convinced him it had value, and in a couple days it was added. The real power is the fact the curves are mapped to the U-V of the base face and are adjusted to correspond with the U-V of the other. In short the two faces do not have to be the same size. In this case if you adjust the model length the text goes with it, without needing to adjust the lettering sketches.

While VX has its faults and need for improvement. I am always reminded that adding a function like Wrap to an existing Cad package in a couple days can only happen with VX. So while I still have my wants, I hope hanging in there with VX my dreams may someday come true.

I would have recreated the text to make it smooth and tangent. We try to keep our sketch curves as lines and simple arcs, which keeps the math simplier and the results better.

John

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smd

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Message 17 of 22

14-11-2009 10:24 . am   |   View his/her posts only
Hey Paul, I never loaded 13.7 so maybe thats why I cant open? See attatched. It only shows up as i don't know what kind of file, and it will open, it just doesn't show anything?

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Mike

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Message 18 of 22

14-11-2009 11:43 . am   |   View his/her posts only
I was able to open Paul's file. There should not be an issue opening a version 13 file in version 14, you just can't go the other way. I did however discover a small bug. The divide4 command in the history labels the faces the opposite of V13. The subsequent offsetface5 offsets the outer boundary instead of the inner and the part falls apart. no pun intended. A quick edit and it came back together.
I will reattach his file here in V14. Paul's version 13 file only rotated 45 degrees, this one goes 90.

Paul, you may want to morph your V13 file 90 degrees and check the stl again...if you don't mind.

I have also attached a screenshot from 14.20. There is a new option "Minimize surface data". The file size went from 7,423 to 1,240.

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smd

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Message 19 of 22

14-11-2009 01:27 . pm   |   View his/her posts only
Funny, i'm still gettin the same when i try to open. Does my attatchment give youu any clue as to whats goin on?

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Mike

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Message 20 of 22

14-11-2009 01:43 . pm   |   View his/her posts only
Here is a zip of my 14.20

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ChrisWard2k2

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Message 21 of 22

14-11-2009 04:13 . pm   |   View his/her posts only
Hi Scott

In your attachment, Paul's file name is shown as "GL%5FSimpleBead%2EVX".

It needs to be re-named to "GL_SimpleBead.VX".

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smd

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Message 22 of 22

14-11-2009 05:16 . pm   |   View his/her posts only
Yeah, for some reason when i grab vx file from here they get mucked up by the time they land on my lap top. I then need to rename them.......weird.
See also
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