Design question for the experts - How to create a foam board

[RAM]

There is something I don't understand about drawing programs. Maybe one of you can explain how I would go about doing this:

I would like to create an object to draw my plan on. Object might be the wrong word. What I'd like to do is create a single sheet of Adams foam board inside a drawing program. I want it to "know" that is 20x30 inches, and that it's thickness is due to 3 layers of material (paper/foam/paper).

I'd like to be able to load a foam board into a drawing/cad/design etc program, then draw my cuts on it, including A and B folds. I want to make these cuts inside the program. Some of the cuts only removing two layers of the board so I can see how it folds before I cut the real thing.

Can this be done? It would make life a lot easier for my non-engineer brain.

 

[earthsciteach]

Absolutely, it can be done. How to go about it is very dependent on the CAD software you are using. You can create a 3d rectangle to the dimensions of the foam board, draw on the top layer and remove the appropriate "material" in the software package.

 

[RAM]

Thx for the reply. I have no practical experience with cad software and don't have a good reason to spend $$$ on a big name version. From your reply I realize it must be 3D software not 2D (should have been obvious but I missed that). Is there something out there besides sketchup that you would recommend for a rookie? I tried sketchup but didn't like it. I'd rather punch in numbers to define the part.

 

[TEAJR66]

Ram,

I have been stuck on Sketchup because the first design example I saw was made there. The price was the sticking point.

There are a few shortcuts that I learned that make it much easier.

1. I don't try to model the material that will be used as the construction medium, I.E. the foam. The thickness of the foam and the layers work out in the wash once you get used to using a couple basic sets of geometry that are consistent.

2. Giving faces bright, contrasting color makes it easier to keep parts organized and oriented as you unfold.

3. Printing to CutePDF from Sketchup is a great way to get your 2D plans to PDF.

4. Use the 3D warehouse. Plenty of people have already modeled common components, I.E. power pods, batteries, servos and other pieces parts.

5. Setting up the Model Info before starting a new model allows you to set the units and determine accuracy.

6. Editing Styles by Material will let you do all your line coloring in the model before you print the plans.

7. Make items components and save them often and as their own entity. They come in handy later when looking to manipulate changes.

8. Unfolding goes smoother if you align the axis's to the line you are unfolding along.

If I ever get a decent screen capture program, I will make a short video that outlines a few of these things so they make more sense. "A", "B", and even "C" style folds are easy once you understand making an outer skin, adding thickness, intersecting, then deleting voids. Then you delete the thickness and start unfolding.

 

[Vimanse]

Sketchup is the way to go.. I use it all the time.In fact there are some great tutorial in the article section.Also when you get good at it you can make STL modals and 3Dprint them.
_V

 

[JUSS10]

I'm going to say use Draftsight. Its a 2D program. I personally much prefer drawing my planes in 2D since that is what they will be cut in. It doesn't require the need to "unfold" the planes from 3D to 2D. Its very easy to use and most planes you start with a 3 view drawing anyway. You can just import that 3 View drawing in Draftsight then scale it to the size you want. Trace the profiles of the plane then start to modify it to work for foamboard. That said I have been using cad for years and due to that I have a solid ability to think 3D while drawing 2D. I plan to write an article on using draftsight just for this reason. Its freeware like sketchup.

Justin

 

[AkimboGlueGuns]

The educational license for Autodesk Inventor is now free if I remember correctly. It's a great program that will do far more than anything you'll need for DTF design.

 

[RAM]

Thanks for all the replies. I've tried sketchup and couldn't get the hang of it. I have draftsight downloaded but got hung up on the idea of wanting something that would let me create a piece of foam board and try things with it like scores and cuts and then fold it, not unfold it. Maybe there is no such thing.

 

[Craftydan]

Pepakura.

it'll take a 3D rendered object with defined "seams" and unfold it into patterns. it's mostly used in the papercraft hobbies and you'll have to make allowances for your material (5mm foamboard doesn't fold on clean edges like paper), but it's an effective unfolding tool.

http://www.instructables.com/id/Design-Papercrafts-with-CAD-software/?ALLSTEPS

 

[RAM]

Pepakura.

it'll take a 3D rendered object with defined "seams" and unfold it into patterns. it's mostly used in the papercraft hobbies and you'll have to make allowances for your material (5mm foamboard doesn't fold on clean edges like paper), but it's an effective unfolding tool.

http://www.instructables.com/id/Design-Papercrafts-with-CAD-software/?ALLSTEPS

Pepakura with the ability to define the material being folded would be perfect. I've been looking at it for a while now but as you said, it only see's a sheet of paper. If only they let you define a 3 layered adams board

 

[Craftydan]

Pepakura with the ability to define the material being folded would be perfect. I've been looking at it for a while now but as you said, it only see's a sheet of paper. If only they let you define a 3 layered adams board

That you'd have to do manually, but it's not really that hard. Treat your unfolded template conceptually as your outer skin -- the only difference between the outer skin and the inner are the reliefs. Design in 4.5-ish mm reliefs on one side of each 90 fold you'll cut on the inner layer. With the right tools you could even leave them out of the plans and simply cut them as you prep the piece for folding -- who needs lines when a foam spacer between two blades cuts the groove perfect every time? shallow bends (like the F22 nose, or wing creases) you can let the foam get crushed. sharp bends (like wing LE) you'll cut bevels to suit. C-Folds, naturally, would have to be sized manually.

Build, test, then go back and manually draw in parallel lines in your publishable plans where the build worked (assuming you want to publish them).

Your biggest challenge is still that 3D model to unwrap. The rest is tweaking and cleanup -- that can be done "on the fly".

 

[RAM]

Treat your unfolded template conceptually as your outer skin

I think that is my problem with cad in general. I get hung up on the thickness problem. Thanks for the outer skin idea.

I'm still looking for software to make it easier and went a different route this time. Still pulling my hair out but went to the basic idea of what we do, that is, we make boxes . Doing that kind of a search I stumbled onto this software. I'm getting closer to what I want.

 

[RAM]

Looked into the cardboard box software a bit further. This explains some of what I was trying to figure out using cad or sketchup. ( http://www.packmage.com/help/469-B_in-Lose-and-out-Gain.aspx ) They do take thickness into consideration when folding. Not sure, but I think it lets you make a custom box. If it does, maybe it will work for planes.

 

[TEAJR66]

From what I can see, in my limited experience, is that the material thickness does not matter as much for most of our folds. The "A", "B". and "C" folds all get the bulk of the material removed (always equivalent to the thickness of the board for "A" or "B", and 2x for "C"). Beveled control surfaces flex on the paper or tape joint with the bevel making room for the thickness of the material. This leaves the double bevel, where we form leading edges. Since the double bevel does not remove all of the material that would get in the way, we compress foam and get that slightly rounded leading edge. The last place where we run into a problem is crease and score lines where no material is removed. But in that case, again we are working with foam, the material in conflict is easily compressed and becomes insignificant.

In end, my goal is not to render a pretty model on the computer. I want to produce a 2D set of plans that tell me where to cut, bend and fold the foam to make it look like a plane. In most cases, that geometry can be worked out directly on the foam board with a ruler and a pencil. The 2D plans come in handy for reproducing and sharing favorable outcomes. The 3D portion helps me work out the more complex geometry of things like the length to cut a flat piece of foam that will fit once curved or where to divide pieces that span more than one sheet of foam board (and have those pieces match up once assembled). Its also great for saving things to be used again.

I will be very interested to see what different software you use to achieve your goals. Rite now, I am trying to learn Inkscape. Then there is the whole new world of Adobe Reader that Craftydan opened for me when he introduced me to the ability to measure in Adobe. Good thing I got time to be on the computer.

 

[RAM]

I've seen several references to an Inkscape extension called Render. Under Render should be a choice called "foldable box"
You might want to take a look at that function. I haven't found instructions for it yet. I'll probably try Inkscape as well.

As for the cardboard box software I found, I can't get it to work from a download. It wants me to sign in and I don't trust that. The software didn't even open, just a login screen. It may be a dead project.

I have played a little with this software. It has a sheet metal box function that I need to explore.

 

[TEAJR66]

I will check out Render for inkscape. Stroke and fill (the supposedly easy stuff) is still kicking my butt.

In the mean time, I have been trying to use screen capture software to make a Sketchup demo. Constantly locking up my computer and clogging up the works. Oh well. What are ya gonna do?