c-grain

Hey fellow scratchers,has anyone out there ever bought a Revell plastic model and sliced it up at various stations to get outlines of bulkheads for example to draw your own plans from?I've read over the years that the plastic models are very acurate scale!I plan to build a 100" or so P2V-7 Neptune this winter and am having a hard time finding acurate plans for this bird.You see,I was a flight crew member(DCO)back in the mid 60's @ Point Mugu Naval Missel Center.Sure wish I still had pics. of the one I flew in[]The P2V had 2-recips.and 2 jets for power and was fast for a bomber of 100'span---approx. 365 MPH!Perfect for 2 electric outrunners and 2 electric ducted fans.Also,counter-rotation is easy with electric.

RAMFlyer

My Feedback: (65)

An excellent series of articles on exactly how to do this is included on Mike James' CD entitled "How To Do Everything" Volume One. Well worth the $30.00 (including shipping)! Check out Mike's website at http://www.nextcraft.com/

Mike is a great guy who will be happy to answer any questions you have about his CD. I'm looking forward to his next CD on CAD use for models.

O2man

My Feedback: (5)

Hey guys----take this as a big 'Me Too' re: "How To Do Everything" Volume One. There is too much information in there to digest quickly. A great effort on Mike's part. I am afraid to think what will happen to my spare time when the CD on CAD for models releases. At least I'll be staying out of trouble.

F86_SABRE

Hi

re: P2V NEPTUNE

Plastic models are not exactly made to scale. If you read write-ups in plastic type magazines they often measure the kit against known dimensions and often criticize the fact that kit dimensions differ with plastic ones. Well do you have a choice? If yes than go for it.
In the case of the Neptune I managed to locate a very good publication from a UK source and bought the book which contained excellent drawings of the plane. The book also included fuselage formers. The weblink is here:

http://www.warpaint-books.com/

I believe these publications are also available in the US.

Alternatively, here but without fuselage formers:

http://www.airwar.ru/other/draw/neptun.html

Needless to say having a plastic model well greatly assist you in obtaining a holistic view of the plane. I believe Mike James contribution in furthering this project will greatly enhance the knowledge.

Hope this helps.

Regards

Reuben

F86_SABRE

Well here is what I have been up to lately.

This is the Breguet Atlantic. Its a European Search and Rescue plane. I had a very hard time locating any plans. Infact, I was not succesful! [:@] The only thing that I could come with was the Revell plastic model. The plane had an added complication as it had a double bubble fuselage from almost the front until the end. Needless to say the the plastic model was used as reference and managed to establish around 14 fuselage formers.
I had a numbers of photos to assist me and also the JANE'S (all the world's aircraft) which contained some interesting information.
At the moment I am doing the wings using Compufoil 3D and this has an intersting 3D feature which greatly assists me in viewing the final product. Unfortunately I am not capable of making a 3D drawing of the plan as it would have been an excellent presentation but still.

After making the wings I intend to start the fuselage construction process. That should keep me busy for the next few days. Thereafter the engine nacelles.
The dimensions:
Fuslage length including MAD boom - 111.5"
Wingspan: 128"
Expected Overall weight: around 35-40lbs
Power: 2 x 3W 42cc each

Here are some shots from the p/c


Reuben

c-grain

Hi guys, I thank you for the replies!It's been most helpfull.

BMatthews

Truthfully if you're looking for more of a stand off scale model rather than a World Champs contest level entry where it'll be measured with digital calipers then making a set of drawings that way is fine. As long as you can look at the plastic model and not see anything glaringly obvious. Back when I was a kid I did plastic models before discovering the joys of flying. Even at that tender age some of the plastic kits were obviously way out. Revell was, at that time, one of the worst. If you can get a Monogram version I would tend to trust that more.

CoosBayLumber

My Feedback: (1)

As Sabre mentioned not all of the plastic models are accurately proportioned.

However, one important item is that a plastic model does not fly either. You still are going to have to go back in and alter the flying and control surfaces to more appropriately match the model formulae. There have been several mentions in magazine on how to alter known good and accurate real aircraft plans into something that is controllable, especially on twin engine designs. We also shed some doubt whenever scale airfoils are mentioned also.

Wm.

allanflowers

If I am not mistaken, in some scale contests you can use a plastic model (unpainted) as scale reference for outlines, etc. Therefore the plastic model, correct or not, becomes the criteria upon which your RC model is judged.
So you could buy two plastic kits, cut one up and use the other as scale reference. However, don't take my word for this as I may be mistaken.
Allan

clscale-RCU

My Feedback: (7)

I took a short sunderland plastic model, ground it down every 1/4" then scanned the cross sections on my flatbed scanner (put the plastic model directly on the scanner). then traced the cross sections from the bitmap scans. Make sure you don't change the resoution when do the scans.

If the plastic model fuselage is 10" long and your enlarged 3-view has a 50" long fuselage I enlarged the cross sections I got from the bitmap scans by 5 times (50/10 =5x). Since I scanned every .25" that meant I had a cross section on the 50" fuselage every 1.25" (.25 x 5 = 1.25). I made prints from the computer from the bitmap scans, traced the cross section and then enlarged that trace until it matched the height on the 50" long fuselage plans. Process works great, but remember all errors on the plastic model kit will be magnified when you enlarge the cross sections. You may have to clean up the cross sections after they are enlarged.

Good luck,
Fred Cronenwett

CoosBayLumber

My Feedback: (1)

I do not work in 3-D for my plans. Seems to me a good year or two ago, some reader to RCU from South America was advertising a miniature 3-D scanner at around $2500. He would roll it around on a table top, side, top, front, etc. it would scan the model, and then the results could be worked up in some CAD software. Thus the original model was not harmed in any way.

Currently big thing now being advertised in engineering magazines are firms who will scan the interior of some room or a bridge and then do some conversion in order for the customer to make up their own drawings. Some times the original drawings are gone, or the structure has been revised so many times, it no longer resembles how originally built. Fee is about $1500 for a crew of three, and full day. I think the costs of the special scanner are coming down substantially now. Perhaps within a year then, any of us could obtain one of these more affordable and with proper software then make a three view.


Wm.

DanSavage

My Feedback: (5)

You can slice it up if you want. I've known several designers who've used this method with good results.

The only problem is that once you've sliced up the model, it's pretty much useless for anything else. I personally prefer a less destructive tool that will accomplish the same end result. That way, if I need additional cross-sections, I always have the original model in perfect condition.

I like to use a contour gauge, such as the one seen below to copy the cross-sections. Once I've got a clean cross-section, I trace it onto a piece of paper and when I have all the cross-sections, airfoils, etc. I need, I scan the whole lot into a computer and then import the raster image into my CAD program and 'trace' the cross-sections into vector format.

The first model I used this method on was an electric-powered Aero Spacelines Super Guppy, including fuselage bulkheads, wing/tail airfoils and nacelle formers. I've also used this method to create a twin-edf model of a Sukhoi Su-27 Flanker.

das20v

Perhaps you could apply a cureable modeling clay over your fuselage or wing halves and make a moulding off of that....cure it, remove it, then slice the moulding into the sections you need....that way you arent wasting your plastic model kit by chopping or spending large sums of cash for a scan.

Just an idea I had...

smithfj

Hi c-grain. I think Mike Beaulieu has a set of plans for the PV on his web site. It's 103" span. Go to www.scalercmodels.com and check it out. If not listed give him a call. He has excellent drawings as he use to do them for Scale RC modeller magazine.
Frank Smith