Thank you very much!
In this instructable I will demonstrate how I went from a photo to an actual 3D item! All were done with free software. You will need the following:
- Google SketchUp (Free Edition) incl a STL exporting script/plugin.
I used SU version 8 in this instructable. There is a SketchUp2013 released, but as it now has new owners, I am not sure what features are available in their free version. The STL script I got from Ruby Library Depot (http://rhin.crai.archi.fr/rld/plugins_list_az.php)
for checking if model is "manifold" (Mani.. What????)
Step 1: Take Picture! (Or Use Any Other Suitable Image)...
Also, measure the dimensions of the missing piece! In my case, I measured the maximum width of the battery compartment with a vernier. You will need this measurement in the final step of your design. If you cannot measure the item since you are working off a picture of an unknown item, try to find a size reference in the image.
Step 2: Import Image Into Google Sketchup...
Google offers this software to everyone with the purpose of having everyone build their house or work building and then upload it to Google earth for their 3D street view. BUT..... Sketchup is so much more powerful....... That's why we use it here!
I used Sketchup v8, which has a "Match Photo" feature. (I believe that some of the earlier versions of Sketchup also supports this feature, but I'm not sure which of them do. Sorry) This is the feature that makes it all possible!
Sooo.... Go ahead and open Sketchup and use the match photo feature to import your image.
Step 3: "Match the Photo" With Your Image...
The idea is to align your X and Y axis of Sketchup with your image, thereby "Matching" SketchUp's camera plane to your image.
It is important to say that, the more correct the alignment of the axis, the better precision your 3D part will have!
Align the two red dotted lines (X axis) with sides/edges of the device in your photo. You can zoom into the image with your mouse wheel for better accuracy. Align the two green dotted lines (Y axis) with sides/edges that are perpendicular to the red dotted lines sides/edges.
Drag the yellow box, which is the center of the axis (origin point), to a suitable location.
Remember to save your work often.
Step 4: Start Reconstruction of Missing Piece...
SketchUp offers plugins that expand the versatility of the software unmentionably! (eg: The "Sphere" and "Find The Center Point" tools!) Once again these plugins can be found with a quick Google search. (eg: "SketchUp Plugins" or "SketchUp Ruby Scripts")
No external plugin are necessary to create your model BUT, as you reconstruct your model you will probably find that there are some things that you struggle/find difficult to do. That's where a plugin/script might help you (because someone else probably also struggled with the same issue and perhaps had the know-how to write a plugin script).
If you want to view your model from a different angle than that of the match photo image, you can just select one of the view tools (rotate, pan and preset camera views) and change your view. You will notice that this makes your match photo image disappear! Don't worry, it is still there. To return to the match photo view, simply click on the scene tab underneath your toolbars (to the left).
You will be able to get much more detail into a model by changing to various views for editing and then switching back to match photo view.
Step 5: Model Touch-Up and Exporting...
Once you are complete touching up your model you can export it to a 3D printer readable file type. (Usually STL, DXF, GCODE etc.) I prefer the STL format, as most 3D software are capable of viewing/editing them. The free version of SketchUp does not have a STL export feature. Luckily, the kind people over at the SketchUp plugins websites have loads of free plugins that will import and export your model as a STL file. (For example: "http://rhin.crai.archi.fr/rld/plugin_details.php?id=429" is a nice SU-To-STL plugin.)
Select all of your newly created model and export it to STL. (With which ever way your plugin requires. The above mentioned plugin is situated in the "Tools" menu and requires that you select an exporting unit. My SketchUp template is set to "mm" and I therefor select the "mm" export unit.)
Step 6: Manifold Check and Printing!
Now we will use the other free CAD program I mentioned in the beginning namely, Blender! (Yes, Totally free!) This is an extremely powerful 3D model creation software program. (But it can do so much more... From motion tracking of real video and adding video special effects, to creating standalone games and of course, 3D printing! It's like the poor man's Swiss army knife for 3D printing, CAD, Image & video editing, particle physics simulation, games and more!
We will use Blender for the express purpose of checking to see if our model is "manifold" (or solid). This simply means to check whether the model is watertight. (have any holes in the model.) 3D printers cannot print models that have holes in their faces/edges/vertices. That doesn't mean you cannot print something like a doughnut! It's more like having a model of a tooth, with a small cavity. Any holes in your model that would cause water to flow into the inside of your model structure (like in-between the two outer walls of a house) is referred to as "non-manifold" faces/edges or vertices. Once again, a quick Google search regarding this would explain much better.
Blender checks manifoldness effortlessly. The new version of Blender, v6.7 has got a whole range of 3D printing tools bundled with it which makes your life so much easier. One of these tools is the "Check if geometry is solid" in the tools menu. For older versions of Blender (2.4, 2.5 & 2.6) you can use the keyboard shortcut: "Ctrl + Shift + Alt + M".
Now, in Blender, delete the default cube in the center of the display. Import the STL file of your model. Once imported, select your model and press "Tab" on your keyboard to enter edit mode. Then perform a manifold test as stated above dependent on your Blender version. If your model is not solid you will have to fix the problem areas. Unfortunately it is not in the scope of this instructable to explain how to fix these errors. The help information in Blender (and the internet) should be sufficient.
If your model is manifold (solid) you can proceed to the next step. If you had to fix the errors in Blender you have to first export the model as a new STL file.
The final, and very important step! Remember to scale your model to match the size of the item you measured in the beginning! This is done by simply selecting the whole model and pressing "S" and then dragging your mouse. When the scale is satisfactory export your newly made model as a STL file.
When this is all done...(phew)... you can send the STL file to any 3D printing software for slicing into "gcode" and finally, printing!
Step 7: And Finally...
Thank you once again for taking the time to read this instructable and I hope this helps and inspires some new ideas in a few people in the future!
Good luck and God bless!