Hi Guys

I've been thinking about taking an obscure WWI airplane that my older brothers and their friend built and flew when I was a little kid, probably about 7 years old, and building one today as a tribute to them. It was flown on 70' lines with both the Super Clyclone & Anderson Spitfire ignition engines, and probably a 14" prop.  Anyway, all I have currently is a decent 3-view drawing.  So I'm asking you guys with experience taking a 3-view and turning it into a set of plans to build from, to give me some direction. Theirs was about 60" span, but I would like to make mine about 69" span.  I don't know how to go about taking the 3-view and enlarging it to a full size plan. Any input from those that have done this is appreciated.  I'm all ears !   

Dan:

If you have decent three-views with cross sections at stations, you can simply sit down and manually draw enlarged plans to any scale you want. For example, if the wingspan on your three-view measures 3" and you want a model of 60" wingspan, you will multiply every dimension that you take off of the three-view by twenty to draw your plan. That probably is an over simplification. For example, the Beech C45J that I am doing now started as a set of Paul Matt three-views. I determined that if I wanted a 48" wingspan, I could measure the three view with a 40 scale on an engineering ruler and multiply that measurement by 1.09. I used that factor (40 scale times 1.09) for all of the measurements and the plane is looking great. This is the method that I have used for many planes and it has always worked well.

I understand that there are ways to do it with a computer drafting system, but I have no expertise and therefore can't really comment on that approach. I envision that the computer approach may be somewhat expensive the first time around.

Jim Fruit

Making a full set of plans is pretty time consuming if you are only building one plane.

With or without a computer, the fast way to do this is to find a published plan of a model similar to what you want, and build that model only with your outline.  At best you'll pick something with a similar size, and a similar layout (i.e., engine type, mono- or biplane, low wing, etc.).  So for instance if you want to build a 67 inch span LaGG-3 you could start with 70 inch P-51 plans, or if you wanted to build a Lysander you could start with plans for a Monocoupe or a Cessna C-185.

To do this, take your 3-view, and copy (or scan) them.  Then take whiteout and white paper (or fire up your favorite graphics package) and scrub off any of the interior detail on the 3-view, leaving only the outlines of the wing, fuselage, and tail.  Then take your newly un-detailed 3-view and have it enlarged (or printed out) to the scale that you want to build your airplane.  You probably want to do this at a local blueprint shop -- places like Kinkos will do it, but they want a lot more $$ and generally don't have as knowledgeable or interested help.

This is your "plan".  Remember that it leaves out a lot of detail, but you know the plane designer pretty well so any time you have questions you can ask.  (Because you're the plane designer)

Now clean off your dining room table and lay out your 3-view on it.  Lay your magazine open to the plan that you're shamelessly plagiarizing (ehem) borrowing from, and study it and your 3-view.  If you feel the need, grab a pencil and transfer the interior structure from the magazine plans to fit within the outlines on your three view.  Put the spar on yours where the designer calls out the spar on his, use his fuselage structure, etc..  Use the same wood sizes, etc., to the extent that you agree with the original designer.  You'll need to redraw all of the formers (this is why Jim was suggesting that you start with a 3-view that has sections).  Make the formers to match the sections on your 3-view if you have them, or fake it if you don't.  If you don't know how to go from the 3-view sections to former outlines Google on "lofting" or ask here.

Now go build.  You'll find that from time to time you'll have built yourself into a corner and you'll have to back up and redo (i.e., you'll have to whack things off and start that part over).  That doesn't mean your bad -- that's just part and parcel of designing your own model to build.

I've built a few scale planes where I just blew up the 3-view to the size that I wanted, and started building, faking the structure as I went.  It's fun to do, because then when someone asks for the plans you can just give them a look of pure naive innocence and say "plans?".

Have fun.

Guys

I don't have a scanner as yet, so I can only show you the link I got the 3-view from.  The 3-view doesn't show fuselage bulkhead stations. I believe the fuselage sides are flat from the cockpit rearward.  As far as the wings and tail surfaces go, I think I could build them off a full size enlargement of the 3-view. It's mostly the forward fuselage and the rear turtle deck that I don't know the shape of.
http://www.aviastar.org/pictures/england/west_wagtail_1.jpg
http://www.aviastar.org/pictures/england/west_wagtail.gif

I looked at the three-view again and the front view most likely shows the fuselage cross section at the line of the front cabane and front gear strut. I would carry the curved top section unchanged to the back of the cockpit. The only complex shape seems to be the transition from the circle at the engine to the x-sect at the front gear leg.
Chuck

Dan-

I've done several 1:1 copies at various area copiers (as you know, that's Cleveberg) and have found several things to be normally true:

1) The copier people, regardless of how good at their work, will not anticipate nor recognize your desired accurascy.

2) They often distort the proportions through faulty feeding of the paper, if they do not have a large scanner bed.

3) Depending on their equipment, there may still be optical distortions in the digitizing of the images.

4) in your case, you can add that any errors in the small 3-V (original or from some scanner) will be magnified greatly, as will line width and waviness, if you are enlarging from the apparent size of your 3-V to to a 69" model.

You can get around most of these things if you measure and scale convenient perpendicular dimensions so that you can measure on the spot and request them to rescale. I always take my pocket calculator along so that I can take the ratio of their product dimensions to what I want, so that I can give them a revised scale factor. This is a real pain in the arse every time! To this you can add that too often, after you have found a good copier bunch and "train" them to do it right, they will no longer be in business next time you want them.

SO...here's my suggestion. That plane has, as predicted above, many straight lines and simple geometrical curves. I'd just carefully measure the span (or, for instance, a wheel) and choose a scale factor (multiplier) that allows you to equip the model with scale accessories and gets you closest to your desired size. Then just draw the outlines to scale and draw sections/loftings to fit. I do not think that this will take very long in comparison to your build time, and you will not have to pay for something that will only be a guide for doing most of this work anyway. Give me a call, if you want to discuss this.

SK

Chuck

Your observations are noted.  Maybe once I have a full size 3-view, it will be more obvious. So is Kinko's the only place to take my little 3-view and get it enlarged to full size ? 

No no no!!  Kinko's is the only name that you can find anywhere in the US to do the job.  It's probably also the worst.

If you can find it, a blueprint shop that caters to structural engineers and architects is best.  They'll have big copiers, and staff that is used to picky customers.  Certainly the one here in town is happy to help me with my oddball printing requests (and they charge about 1/2 what Kinko's does).  Serge's suggestion about finding pertinent dimensions and making sure that the thing comes out square and the right size is a good one.

I would also suggest that you download a copy of Bob Banka's 3-view directory, and see what he has.  He's got lots of 3-views, so even if the plane is obscure there's a chance that he's got something (after all, someone has draw up a three-view of that plane, because you have it).

Tim

Thanks for your suggestion on the blueprint shop.  As far as Bob Banka goes, nothing there, I checked, and I would be shocked if it were, cause this particular airplane is not known by many. I believe there were only 3-5 ever built. Thanks

Dan,

I offer a drawing service for just that. I just completed drawings for a model 144.5" in span and another 85" in span, from a supplied good three view.

I can make them any size, as much or as little detail as you choose.

From my drawings, you can add construction detail to aid in your building process.

CB