Sprayed-on 3D Printed Pattern Filler

[Jasonb]

That is one of the reasons I don't like using STL as unless you know the units that were used to create it you don't really know what to put into the box that comes up on import.

Also as they are made like a wire frame you can't just use the measure tool of your CAD to click on say the OD and find out the diameter/radius

Compare pats STL with a STP. Pats I have to choose two points but as there is no ctr can't get exact diameter/radius. Mine just click the edge which highlights in blue and I get the diameter, radius and circumference

 

[GreenTwin]

We need to document somewhere all the file sharing formats, and what each is capable of doing.

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[Jasonb]

The ones you emailed me are still problematic, they will open in F360 but if I try and export them from there as STEP files they won't open in alibre. It may be the files are from your slicer software rather than your CAD and something may have been added.

Here is that small flywheel in STL, STP & IGES it's just under 3" dia. and also a jpg. Forget that two this site does not accept and the STL was too big

 

[ddmckee54]

File compatibility between CAD programs can be problematic at times, because not everybody plays well together.

For 2D drawings MOST software packages will import and export DXF files, that's Drawing eXchange Format files. AutoCAD and its' clones will use a DWG file-type as their basic drawing file-type. Then import or export to DXF, and possibly other drawing formats. Pretty much everybody has their own proprietary file format, you will need to check your particular software to see what file-types it can import or export.

For 3D CAD the waters get even muddier, you've got 3D solids, 3D Meshes, 3D wire-frames, and, and, and.. What your 3D CAD package uses depends entirely on the WHO the package is aimed at. Engineering 3D CAD packages tend to use solids, Artsy-Fartsy stuff where you have lots of flowing organic shapes tend to use meshes. 3D solids can also be displayed as a wire-frame by some 3D packages, these can be VERY confusing if you are not used to using them, but 3D wire-frames can also be exported in a DXF format.

Some 3D CAD packages will let you import 3D Meshes and convert them to 3D solids. Usually what you will get is a multifaceted solid because the STL file consists of nothing but triangles. Even a simple rectangular surface, in an STL file that rectangle is 2 triangles. The better and more sophisticated software packages will recognize curves and surfaces, and try to simplify the solids into something more usable. Even those will usually have an upper limit to the number of facets that it will work with.

In short, the list of what's compatible with what, will depend on what 2D or 3D package you are using. I used to use DesignSpark3D and they had their own file format, RSDOC. And NOBODY else used that, or could import it.

 

[GreenTwin]

I tried saving a flywheel 3D model in various formats that are optional in Solidworks.

The test was to create an export file in another format, and then open it in Solidworks, and check to see if the object could be modified.

Most of the formats would not re-open in SW.

There were some options on the STL and STEP formats, such as include the layers, but those files did not reopen.

Saving in plan STL, STEP and IGS created files that would open, but only the STEP and IGS objects could be modified in SW; ie: extrude-cut, etc.
The object opens in SW as one piece, and the various layers are lost, but at least with the STEP/IGS you can select a face, and make some modifications to the object. Not ideal but better than not being able to modify the object at all.

As far as DWG/DXF 2D files, I have found that in some/may/most cases, exporting a 2D drawing from Solidworks may or may not be productive, since the views often contain multiple broken lines, where SW is approximating what would normally be a continuous spline, or simlar item.

I generally create a clean set of drawings 2D in Autocad, and check it against the SW DWG file, as far as making dimensioned drawings to be used for construction, and use the exported isometric views from SW, since those are not dimensioned, but are just for information/reference.

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[Bazzer]

I tried saving a flywheel 3D model in various formats that are optional in Solidworks.

The test was to create an export file in another format, and then open it in Solidworks, and check to see if the object could be modified.

Most of the formats would not re-open in SW.

There were some options on the STL and STEP formats, such as include the layers, but those files did not reopen.

Saving in plan STL, STEP and IGS created files that would open, but only the STEP and IGS objects could be modified in SW; ie: extrude-cut, etc.
The object opens in SW as one piece, and the various layers are lost, but at least with the STEP/IGS you can select a face, and make some modifications to the object. Not ideal but better than not being able to modify the object at all.

As far as DWG/DXF 2D files, I have found that in some/may/most cases, exporting a 2D drawing from Solidworks may or may not be productive, since the views often contain multiple broken lines, where SW is approximating what would normally be a continuous spline, or simlar item.

I generally create a clean set of drawings 2D in Autocad, and check it against the SW DWG file, as far as making dimensioned drawings to be used for construction, and use the exported isometric views from SW, since those are not dimensioned, but are just for information/reference.

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I would like to say that when working with 3D files the least problematic format across a number of different CAD packages is the STP format.

Higher end 3D CAD (the most high brow that I have experience with is Solidedge) have the least problems importing files.

Having said that I use BobCAD CAM pretty well every day and make a decent living from the resulting G codes can handle most STP files thrown at it.

Keep away from STL unless you are going straight into a print slicing programme.

 

[Jasonb]

That's why I tend to use STP too, never had anyone not being able to use them.

As for drawings if you are going to be sharing the Monitor or any other ones then print to PDF then anyone should be able to open them. DXF is handy if people want to pull parts off to laser or water jet cut but that can also be done with the STL files as well as using them for 3D CNC not just cutting out 2D shapes.

 

[ddmckee54]

I don't think there is any one definitive standard for drawing files, at least I haven't seen any. The STEP is pretty close, but even that appears to have multiple standards, ISO-STEP, CAD-STEP, and other flavors... Even the DXF format has changed over the years, and the newer DXF formats are not backwards compatible.

I do agree that the higher end programs have fewer problems with importing and exporting than the lower end stuff does.

 

[GreenTwin]

The latest Prusa Slicer program will import either the STEP or STL file I created for the flywheel, and they both import the same.
I don't see an option to import an IGS file into the Prusa Slicer.

The extention on the STL file is ".STL".
The extenstion on the STEP file is ".STEP", but I think some are referring to it as an ".STP" extension.

I think the Slicer program generates a GCODE file which is sent to the 3D printer.

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[ddmckee54]

Yes the slicer generates the Gcode for the printer. If you think about the math involved in slicing a solid object into a gazillion layers, then calculating the perimeter paths for that object, then calculating the interior fill paths, then optimizing all that crap because EVERYBODY wants to print faster - it makes your head spin.

The fact that Prusa accepts STEP files and STL files is actually pretty impressive for a Freeware program. I believe that the STEP file defines a solid, while the STL file defines a mesh representation of that solid. Did you notice any improvement in the surface finish when using the STEP file in the Prusa slicer, or maybe it sliced faster? Since a mesh is made up of triangles a curve in an STL file is made up of many short line segments. Try importing an STL file into your 3D CAD program sometime, you'll see what I mean.

 

[GreenTwin]

Did you notice any improvement in the surface finish when using the STEP file in the Prusa slicer, or maybe it sliced faster?

My time available for experimenting with 3D printer files and settings has been limited, and so I have a lot to learn about 3D printing and the software used for that.

My goal this year is to start keeping records of every print, and the print settings that were used, so I can start making some accurate comparisions.

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