P-38 Lightning Wing Ribs ... need some direction

[meat]

Okay, I'm happy with my machine. It's ben routing and cutting and annoying my neighbors (you try using this in an apartment building full of whiners!).

Now, it's time to use it for The Big Project.

I'm building a 70% scale P-38 Lightning. One that can actually fly. My CNC machine isn't quite big enough to cut out wing ribs, but the CompuCarveWright machine certainly seems like it's more than capable of doing this (it's got the length!)

I do have a few questions, though:

Can I cut out 1/4" thick stock with the new machine? I've seen some posts that say yea, some that say 1/2" is the thinnest stock the machine will accept. What's the verdict with the new machines sportin' the latest version of the software?

The entire airplane is laid out in TurboCAD. I've also got CorelDraw files (full size) of all of the parts, too. I know that the machine can do cutouts and the software can create cutpaths ... but is there some kind of tutorial on how to do this here? I couldn't find one.

Why use the machine to do these cut outs? because I can't do it. I'll be the first to admit that I can build a kit car or an airplane or anything else from parts ... but I can't make the parts myself with any kind of accuracy.

Thanks for the help!

...and I'll be making kayaks using the machine as one of the tools, too!

Your pal,
Meat.

[Jon Jantz]

Meat, that is awesome, would love to see some pictures of your P-38 project... I have gotten quite a ways towards my private license, but haven't been flying in a while...

I want to build a Vans RV-8 when I have the time and money...

As far as making the cutouts with any accuracy, to me it's hard to bring a design in from CAD or CorelDraw and have it sized perfectly every time in Designer, and I'm not sure why that is... you can easily bring in the shape, use the Outline Pattern tool, select the resulting object and assign a Cut Path... but you may have to resize it in Designer to match the original piece size...

Hope that helps... also, please feel free to post some pictures of your plane over on my forum at AllCW.com...

[CallNeg151]

Well, the machine itself will accept a minimum depth (per the manual) of 1/4", but, keep in mind that so-called 1/4" stock at your lumber yard is actually less than 1/4" thick, and will therefore not be picked up by the board length sensor.

As to the issue of scaling your parts properly, that would be a problem. The only thing that I might suggest is to include a reference shape on each cut out pattern(for example a square that is supposed to be 5" x 5") that you can use to manually scale the piece before deleting it in the final product. Of course, be sure to check the cutouts with a real-world measuring device of appropriate precision to make sure any errors are within your tolerance specs. A 3% error doesn't make much difference when making a sign or a lawn chair, but I suspect would have consequences in an airplane.

Good luck!

[SpiffyDog]

meat,

You could attach the 1/4" stock to another piece of stock using double-sided tape or possibly using a dab of glue on the corners (or any uncarved region) to get the thickness to the minimum of 1/2". Once the carving is complete, separate the pieces.

[meat]

All excellent advice!

I know that wood from the local hardware store isn't 1/4" thick, I'm going to be using my planer to make the wood the right thickness.

I'm not too sure about sizing, though. It looks like I can size the part properly with the software ... but, then again, I dunno yet.

The wood on the double-stick tape stuck on another board works GREAT! Thanks for that tip; I made a few nameplates for a local car dealership using this method.

Your pal,
Meat.

[Chris Cordina]

If the wod is more than 1/4" thick,why not cut first then plane to size.

[BobHill]

Meat, 70% scale? I also would like to see that at the EAA Sun & Fun here in Florida (I'm commercially rated for both airplane and helicopter). I used to see the 3/4 stuff from the Bay area of California, but never a P-38 (only the real ones).

Bob

[cajunpen]

I'm commercially rated for both airplane and helicopter.
Bob

Bob, your knowledge and talents never cease to amaze me

[BobHill]

Thanks, Bill. Actually I'm one of those guys that can't just stand still and I do have a lot of years under my belt to do the things that have challenged me. I suspect that there are many such members of this group here with a lot more experience and things under their belt than I from the sound of it.

Bob

[liquidguitars]

Meat,
Are your cad files only 2d or can you 3D export?