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warx
04-15-2015, 05:27 PM
Hi,

I am working through some choices of CAD software for use with my RL200. One of the first things I need to do is project some letters from the face of a cylinder. Basically, looking for some letters to be mounted on a tube and look like they are projecting outwards. All of the applications I've been trying (Cubify Design, 123D Design, TinkerCAD, FreeCAD) it's not clear to me how I could project a sketch onto a curved surface and then extrude or loft. I was hoping I could loft between two concentric cylinder faces where the sketch had been projected and then increase the radius of one of the cylinders.

My fallback is to extrude the letters then do an intersect with a cylinder with a wall thickness of the intended height but will not have those radiating edge angles.

Cheers,
Mike.

Scotta
04-16-2015, 12:23 AM
I don't have the exact answer, not sure if those tools can do it.
I would suggest looking at Blender. It is a free package that has quite flexible text options
Huge amount of online tutorials.

Joao
04-16-2015, 12:27 AM
I use SketchUp for that.
SketchUp for itself does not have everything that other CADs do, but it allows 3rd party plugins to be developed and added by everyone.

Because of that, SketchUp does literally everything imaginable.
Including, placing extruded 3D text on a curved surface.

http://www.thesketchupessentials.com/how-to-create-curved-extruded-letters-on-a-sign-in-sketchup-without-plugins/

Or even better:
http://lmgtfy.com/?q=sketchup+text+curved+surface

warx
04-16-2015, 12:32 AM
Cool. Thanks for the tip. Will take a look.

Edit: @Joao - just saw your post before I sent the reply below - that is what I need to do! Taking a look at SketchUp as well! Thx.

I think the second method of doing a straight loft and then the intersect with a shelled cylinder is the only way to do this. A couple of things I've discovered with Cubify Invent/Design (which I am liking) is that you can explode text first which helps - but then you can not loft with multiple loops so any letter container an inner bit it can't do. Also you can't do any scaling uniform or not with sketches - just "parts". Oh well.

123D Design is similar but a lot of things just don't work for me (non-uniform scaling etc). Loft sometimes works sometimes crashes. Going to try FreeCAD next.

Joao
04-16-2015, 01:08 AM
The plugin that I use for placing 3D text on a curved surface is this one: http://extensions.sketchup.com/en/content/clf-shape-bender
It does much better job than the extruding the text to the curved surface, and deleting the 'left-overs'.
This plugin does a proper bending of the text.
And it also works with any other object that you want to bend with a defined curve.

901

bolsoncerrado
04-16-2015, 08:14 AM
I did hear the .STL files generated by Sketch up werent too "compatible" for 3D printing... is that so?

Joao
04-16-2015, 11:40 AM
I only use SketchUp and I never had a problem with 'compatibility' issues.

The only problems I have sometimes are if the drawings do not have perfect "watertight" objects. And that is not a 'problem' with SketchUp, many objects in Thingiverse are also badly designed. http://airwolf3d.com/wiki/manifolded-edges-how-to-check-if-your-model-is-watertight-and-ready-to-3d-print/

That thing of SketchUp allowing to have plugins also helps, because I installed a few plugins that can identify if the object is ok for 3D printing, even before I export the STL.

bolsoncerrado
04-16-2015, 11:53 AM
That was the point... Simplify3D requires it to be watertight to process it i think....

warx
04-16-2015, 01:57 PM
Funny as I am having that exact problem now. Component looks good in SketchUp. Looks good in MatterControl layout etc. By the time it gets sliced it's got some odd bits sticking out of what was a clean side. I went back to redo the mating of the embossed text and the solid to see if it would do a cleaner job. Now I can't get the CF shape bender to work again - it won't let me select the single line on the [red] axis. Doing exactly as I did before. Even tried redrawing a single line on the axis. I can select it with the select tool - but Step 2 of the bender tool won't recognize it. Looking at other bender tools now.

warx
04-16-2015, 03:20 PM
Got a little further. Seems Shape Bender is happier if the straight line is not actually on the red line axis itself (just parallel). Still having slicing issues and definitely looks like the bender does not create perfect faces. Below is a picture of the bent object showing missing faces. Also below are pictures of how each of the three slicers handle this (within MatterControl). Cura looks like it actually does a good job. I am going to try to print it (if I can do the crazy offset from middle or wrecked kapton tape trick).

In SketchUp
904

Slic3r
905
MatterControl
903

Cura
902

Joao
04-16-2015, 05:32 PM
It helps a bit if you convert the 3D extruded text into curves, before using the bender.
Even after all of that I need to fix a few opened triangles. But after that the slicer (any slicer) will work really well.

warx
04-16-2015, 05:37 PM
Well hats off to Cura slicer for actually printing correctly! The only downside of Cura from within MatterControl is that it never produces a skirt despite the settings. The skirts in the pic where from the previous STL with errors using MatterControl slicer. Oh well - did not need it for this print.
BTW both slic3r and MatterControl slicers really did strange things with some layers completely empty.
One other thing; I read that the bender works better on larger things (really?!). Well i tried it. My letters are 20mm high but I scaled it up 100 uniformly and redid the operation. I tried the default 10s and 80s for the arc. Both worked much better in the big scale! The 10s had no missing faces. The 80s had just one face missing. Scaling back down to the correct size did not effect the faces.


906

Holgamods
04-16-2015, 09:31 PM
Love Sketchup 2015 and Symplify3D

warx
04-20-2015, 02:51 PM
I tried this again just bending the letters and applying to the cylinder (like your pic above) but this gives me problems printing. The problem is trying to join/intersect the bent letters component and cylinder face cleanly. Even using exactly the same radius and number of segments for the curve it does not fit the face exactly. Pushing it through a tad and doing an intersection works but is impossible to clean up with so many edges to find and erase. I feel like there should be something that does a better job of joining here - perhaps that's what the Union in the Pro Only version does?! I'm using SketchUp because of the Shape Bender (and rather be using Cubify) so once I stop bending letters I should be good.

Joao
04-20-2015, 09:48 PM
I tried this again just bending the letters and applying to the cylinder (like your pic above) but this gives me problems printing. The problem is trying to join/intersect the bent letters component and cylinder face cleanly. Even using exactly the same radius and number of segments for the curve it does not fit the face exactly. Pushing it through a tad and doing an intersection works but is impossible to clean up with so many edges to find and erase. I feel like there should be something that does a better job of joining here - perhaps that's what the Union in the Pro Only version does?! I'm using SketchUp because of the Shape Bender (and rather be using Cubify) so once I stop bending letters I should be good.
I face the same issues.
Sometimes cleaning up the work to be good for printing is a lot of work.
One trick that helped me was to draw everything in a larger scale, and then scale it down to the proper dimensions. SketchUp does not like too much sub-milimeter sizes and rounds things up to 1 mm.

BobenhamHotspur
04-20-2015, 10:08 PM
........The only downside of Cura from within MatterControl is that it never produces a skirt despite the settings. .......
If I remember correctly, in MC it treats brim and skirt as the same thing but differently, if you get my drift :p It's something like, brim is skirt but attached to the model. You should email the MC people they are very good at responding.

warx
04-20-2015, 10:47 PM
You're right - scaling up does help it not to mess up on some triangles! I would think it would all be floating point math - oh well...

I did actually get a clean model before trying the scaling up/down also by doing the inside the 'solid object' cleanup and then running the STL through https://netfabb.azurewebsites.net/ and all the slicers were happy with it! I suppose I'll just need to put that in the workflow. Geomagic did an equally good job too.

Re brim/skirt - yeah it was operator error. Reading the contextual popup help on each field showed me the difference in terminology.