[DesignSpark-Mechanical] Edit STL files

I use DesignSpark-Mechanical as my mad CAD tool.

When I grab a STL file from internet and want to make modifications to it I run into trouble.

I split the STL into smaller parts/surfaces but dispite this I can not edit and modifiy the part. Addind new geometrics works fine but resizing, deleting, cut and subtracting is not possible.

Maybe this is not possible starting out with a STL file. Could going through another format solve this?

Any insight or help would be appreciated.

HV

To edit an STL file, I import it into FreeCAD, convert from mesh to solid, then export as IGES to import into OnShape.

However, the result is rarely satisfactory. Typically, I'd then build a new model using the dimensions and location of the original as a starting point.

On shape is a diffrent Cad software. Have you missinderstood the question or do you mean that I should export from OnShape to DesignSpark?

In DSM you can import the STL into a drawing, then do some very basic operations on it as an STL file- changing holes sizes, etc. If you double click on the edge of a hole, the inner surface of the hole will be selected and you can pull it to whatever size you want. You can likewise select a flat surface and pull it to whatever thickness you want. You won't be able to do much more than that.

If you want to add holes, you can select the whole STL object, right click and select "merge faces" to turn broken up STL flat surfaces into "solid" surfaces. You can then add holes etc., but you won't be able to resize the holes from the original STL. You may or may not be able to fillet edges, etc. depending on the shape of the original STL object.

You just have to play with it to see what you can do in while the object is an STL and after you convert it to a solid.

MeshLab can do all sorts of STL editing, but isn't really a CAD program so it's hard to do things precisely.

---

Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Quote
fotomas
On shape is a diffrent Cad software. Have you missinderstood the question or do you mean that I should export from OnShape to DesignSpark?

I don't know what formats DSM can import. I guess what I was trying to say is that if you convert STL to some other format (e.g. IGES) and then import that into DSM, you might have better luck. But I was also saying that that approach doesn't work well with OnShape, so it may not work well with DSM. I suspect that too much information is lost in converting a CAD model to the STL mesh format to be able effectively convert it back again.

in DSM i just open the new Component DSM creates for the STL and right click on the Mesh and choose Turn To Solid. Now I have an editable faceted solit where everything round is approximated to segments.
It's annoying but DSM is quite smart and does a quick job of calculating STL vertexes and creating the solid.

What I usually do is the following:
1) select a face next to a hole
2) enter sketch mode (k)
3) turn to Normal View (v)
4) select a 3 pint circle
5) randomly pick 3 of the hole's gazillion points and presto, the circle is created
6) I ckeck the actual size that DSM is letting me edit and add some more millimeters depending if I have room or not. I usually add 5 or more
7) Exit sketch mode, select the circle surface created, Push with Substracion to make a DSM-approved hole
8) Click on the hole and resize to half of the number previously remembered (DSM takes Radius after one creates the initial circle/hole)

It's so easy now it became a second nature. I only modify the holes I need to either alter dimensions or use the center of the hole as a "snap to" point.

I hope this helps.

---

RepRap Lander concept on Concept Forge
RepRap Lander concept on RepRap Forums
My Things, mostly experimental stuff