My first swing at designing a plane... B-17

[DamoRC]

The tool I use is called "Unfold".

I am still using the 2014 version of Sketchup because at one point I tried to update and the installer crashed so I just stuck with the 2014 version. So I can't comment as to whether the "Unfold" tool will work with your version of SU.

I tried searching for this tool this morning and can't seem to find a downloadable version (maybe because it's so old).

Attached is the .rb file for the tool. There does not seem to be any attribution to an author in the source (which is weird) so I think it's okay to share here. Just extract the zip file and put the .rb file into your tools folder, or wherever you put your plugins for your version of Sketchup. You will need to re-start Sketchup after adding the file to your Plugins folder.

To use the tool, select it from the Plugins menu and then just click on each surface in order to unfold the piece. As TeaJR66 said, all the adjacent faces need to be oriented the same way to avoid weird folding (but looking at your model you don't seem to have that problem).

A trick I use (read somewhere on the web) is to first create a flat rectangle on your model, then start unfolding your piece. Once the piece is unfolded (but it will not necessarily be flat on the ground plane), perform one last unfold operation by clicking on the flat rectangle - this makes the piece lie on the ground plane.

Hope this helps.

DamoRC

View attachment unfoldtool.zip

 

[EDinCT]

You Guys Rock.

If I haven't already said, Ill say it again. THANK YOU!!!
I was able to figure out the Unwrap and Flatten Faces plugin. It didn't occur to me to do it in small sections at a time. A little bit of a pain to reassemble the pieces, but its actually a good thing because its helping me get better at things like rotate and move.

So here are all the Fuse pieces unwrapped and laid out. Since I use a CNC to cut my pieces Im hoping I laid it out in such a way that I can skip the Inkscape step of rearranging all the parts and go straight to the CAM software to lay out the cuts.

Next question for you guys... whats the best way to export this to a format that I could call "plans"? Im assuming I want to make a DXF file?

 

[DamoRC]

Nice to see you making progress.

I use this tool to export the parts to dxf.

Once installed it shows up in the file menu. To use it, select the part (or all of them) that you want to export. Note: they cannot be grouped parts (make sure they are all exploded). Then it will ask you what units of measure you want to use and then it will ask you for an option for the export (select "Lines"). It will then ask you for a file name for the export.

DamoRC

 

[EDinCT]

I'll Give that a shot next.
I did some research and learned how to add colored lines to the design. It actually looks like a set of plans now! woohoo!

 

[TEAJR66]

There are a couple things I do for making plans.

The first involves a free program called Cute PDF Writer. Once it is installed, it shows up as a virtual printer. After things are laid out in 20x30 space, I make 30x40 boxes and center each 20x30 sheet in a 30x40 box. This works out later when Cute PDF is trying to put a 5" border around things. It makes each set of 20x30 a separate page in the PDF. I delete all the faces because the PDF will print them as white. So just lines. No border for the 20x30 or 30x40 when I print. Once it is all laid out, select Print Setup and choose Cute PDF Writer as the printer. Go to advanced settings and select Custom Postscript for the paper size and specify 30 x 40. Play with it till you are getting one 20x30 per page. When you select print after you are happy, you will get some file save options. Now you will have a PDF that you can share.

For CNC files, there are a couple ways to go.

One is to use the Phlat Script plug in. This will give you the ability to do all the cam stuff right in SU and export G Code. You can find that software at Phlatboyz.com. Some searching on the web will bring up plenty of info on it.

Another way to go is to get an Export to DXF plugin from a third party. I have not found one through SketchUp, but the one I found works great. You can find it HERE.

You can also take the PDF's you make and import those to InkScape and create DXF's that way.

Not sure what CAM software you already use, but I use Estlcam.

A trick to making things easier to work with later on is to make 1/64" gaps before you make the PDF's or export DXF's. Where the different color lines meet, I separate them by 1/64". This helps in my cam software to select continuous lines of the same color. The cut through lines around the perimeter are continuous and the score cut lines stop 1/64" short before they run into other lines. On a PDF, you wont see the gaps, in CAM software it creates a big enough break to keep selections together. Once my stuff is cut on the needle cutter, you don't notice the gap.

Play and experiment, find the way that works best for you.

 

[EDinCT]

That's great info- Thanks!
Last night I was exporting PDF's straight from sketchup, which works, but I couldn't get it to export the scale exactly 1:1. Not a big issue for me since my workflow for the needle cutter is PDF to DXF in inkscape where I can stretch to 1:1 if needed before sending to Estlecam. But I was hoping I would be able to post a 1:1 PDF of the plans for anyone else that may want to try building this thing when I'm done.
Inkscape wont open the DXFs I export from Sketchup for some reason- I keep getting an error. I haven't tried going straight DXF from sketchup to Estlecam yet. I'll take a look at the Phlatboyz thing- Although I like Estlecam, I have to reboot my Mac to use as a windows machine every time I run it and its a pain.

Great idea about the 1/64 gap and glad you reminded me to do that.... I like Estlecams "auto" engrave feature. Also one of the reasons I was excited to tackle this project. I wanted to see if I could make a set of plans that are already laid out to the foam board and CAM friendly!

Once I'm happy I haven't forgotten anything (Which I'm finding a lot of) I was thinking of starting a new build thread. I'm sure there has to be somebody out there interested in seeing if this thing will fly!

 

[Jetcrafter_2000]

Do you also have the problem with sketchup that if you export something to a PDF or even a .jpg sketchup
makes a HUGE frame around your object?
The problem with that is that if you try to print something out 1:1 it´s like 12 sides but just 1 side of usable drawing.

I HATE THIS BUG (probaly fixed with the pay version of sketchup )

See you!
Jetcrafter2000

 

[TEAJR66]

There are lots of tricks and tweaks to get this stuff sorted. Just need to play with it all.

I have exported PDF's from SU, but I prefer to use Cute PDF Writer. One key thing is to make sure all the units are the same.

One thing that helps with the DXF export is to have a CAD program as the default program for DXF files. I use Double Cad (all the programs I use are free, except for the license I purchased for Estlcam). The next important thing is to not rename it when you save. Use the default that is assigned when you export. Use file explorer later to go back and rename. That DXF can go right to Estlcam if you like and avoid InkScape, just in case you don't need to do any tweaks in InkScape. I only use InkScape when I am working with someone else's PDF's or I need to tweak a DXF without changing the SU file.

Check out the Needle Cutter thread for info on running this stuff on MAC and Linux, those guys have this stuff worked out from every angle.

The huge frame: This is how I deal with that. I open the PDF, all the parts already fit on a 20x30 sheet because of the layout. I use the snapshot tool and frame in the parts as tight as possible. Then I print the selection. If you do not use cut marks, the page will be tiled to eight sheets of paper. Sometimes cut marks increases the number of pages, sometimes it does not. Just another thing to play with. I don't really need the cut marks on PDF's because I assemble my tiles on a big window. I use the transparency of the paper to line everything up and tape it all together.

 

[TEAJR66]

This might help. Might not. I have refined this process a little but this covers the basics. I suck at video production, try to bear with it if you can.

 

[EDinCT]

This might help. Might not. I have refined this process a little but this covers the basics. I suck at video production, try to bear with it if you can.

That helps a lot! Wish I had known about that video 3 days ago. Last night I used your advice about the 30x40 and that worked. I can now export at 1:1. Perfect. Also happy you talked about your “fold” components in the 3D warehouse. I was going to work on making some of those tonight... you save me time again!!

In your video you mentioned getting rid of the text 3D attributes- how do you do that?

 

[TEAJR66]

In your video you mentioned getting rid of the text 3D attributes- how do you do that?

When I made that, it had some 3D text attributes. I don't remember all the details, but the result was that it stayed oriented to face you as you orbited. When you import from the warehouse, it will import as a component. Exploding a couple times gets rid of any screwy attributes and keeps it laying flat with the rest of your plans. When you import it, you should be in Top View.

 

[Daniel Kezar]

oh wow. very nice plans and videos. subscribed to the thread.

 

[EDinCT]

oh wow. very nice plans and videos. subscribed to the thread.

Thanks!

Tonight was dedicated to going through the whole plane and figuring out what I was missing. So here is what was added:
- Internal wing re-enforcement for landing gear
- Provision for a removable wing
- Battery tray extended into the nose to give flexibility with the CG
- Fixed a couple formers (missing 3/16" clearance for the surrounding foam)
- Labeled formers (thanks Tommy for the tip on the 3d text)
- Had to split the cabin top to match the removable nose

All thats left is to figure out an initial CG range and then I think its finally ready to use what I learned the last couple days and make a final set of plans.

 

[TEAJR66]

That is a great looking model. I am eager to see the build and flight.

 

[EDinCT]

Here is a short video of the design. Ive said this a million times- but this time, for real, I think its done.

 

[EDinCT]

Tommy- in your video you laid out two 20x30 areas spaced 10” apart and using the rest of your technique enabled you to print a two page PDF.

My question is....
I will have quite a few more sheets that need to be printed. Should I continue to layout the rectangles in the same direction going across? Or start a new level above as I go farther out to keep the same proportions of the final screen zoom?

 

[TEAJR66]

Tommy- in your video you laid out two 20x30 areas spaced 10” apart and using the rest of your technique enabled you to print a two page PDF.

My question is....
I will have quite a few more sheets that need to be printed. Should I continue to layout the rectangles in the same direction going across? Or start a new level above as I go farther out to keep the same proportions of the final screen zoom?

As long as you keep that 10" spacing, it will make one page per 20x30. So you can make it all one row or use multiple rows. Just keep the 10" spacing.

 

[EDinCT]

CG

This picture is a little complicated, but it shows how I am calculating the CG. Has anyone done it this way before?

 

[Tench745]

Your method looks good. I've never done it in 3D before, but I've used it before. I often cross check with an online calculator or something too.
But yeah, I learned the method you're using here. http://www.airfieldmodels.com/information_source/math_and_science_of_model_aircraft/formulas/mean_aerodynamic_chord.htm

 

[EDinCT]

Plans Finished

Thanks to Tommy's great help I am finally finished with the plans and ready to start cutting some foam.

I made the plans CNC Foam cutter friendly... All of the score and crease lines are separated from the full cut lines by a small amount so that setting up in CAM software should be a breeze. I'll find out here shortly. I have no idea how to turn these into tiled plans, but seeing as how it takes up a full 9 sheets of foam, I can't imagine anyone would want attempt to do that anyway.

Im pretty excited to have made it this far. I would be appreciative if anyone could take a look and give me some feedback!

View attachment B-17.pdf