Hi everyone

Just a quick request for help.

I'm wanting to improve my scratch-building techniques and wonder if anyone can recommend either any books which offer good guidance on reading and working with scale armour drawings/plans to take determine armour plate dimensions (sloping armour always seems to defeat me somehow) or software packages (pref free) that can read plans and produce correct templates for individual components.

Very many thanks

Mufty

What subject field are you interested in and or what are you trying to accomplish? I think once we know that we can offer suggested readings that have good scale prints.

Hi Mark

Thanks for your reply.

I'm trying to learn 2 things:

1) How to properly take dimensions from scale drawings, e.g. 1/35th Jagdpanther (but any vehicle in reality), from drawings in plan, side and front views so that the plates are the correct dimensions when laid 2D on styrene sheet, etc.

2) If there is any s/w available, pref for mac, where if a set of drawings are scanned in, by picking out the relevant points on the plan the program will offer the correct template to be printed and transferred to styrene.

Thanks again

Mufty

For that you need to look into how to read orthoginal view drawings. It's a skill taught to those doing drafting. I suspect there are texts/instructions online nowadays (I learned while taking engineering in uni "back when dinosaurs roamed the earth") but this is not a "modelling' skill, it's a drafting/graphics/engineering skill so you could search there for help.

It isn't hard and if I was sitting with you, I could show it to you in under an hour, depending upon your grasp of drawings and how they represent 3D objects.



There are a couple of systems, I think, that will take raster scanned drawings and allow you to convert them to real drawings within a CAD system. They are professional engineering products and not, to my knowledge, available inexpensively. You also have to know how to read the drawing to ensure that the program has interpretted the drawings correctly.

As for printing out the angled sides specifically as templates for model making, no, nothing at all I've ever heard of. If it's in the CAD program, it's not hard to generate "true views" (that's the correct term for what you are looking for) of any angled side of an object and that you could use to create your templates, but, again, you need a CAD system and not a simple paint or illustration program to do that.

Really, though, once you can read a drawing and understand what you are seeing, it's pretty easy to establish the true lengths of the sides and then create the templates yourself. Given how most AFVs are created, it's actually really easy to get true lengths on most surfaces, but there are some compound faceted surfaces that can be a little tricky to get the true lengths for if you don't undertand drawings well.

Get some basic drafting istruction and it will cover it all for you.

Paul

I will agree with Paul, one would need to really sit down with you and see where you are struggling.

I am an engineer as well, so creating and reading prints feels natural to me.

As far as printing templates, I would only do this if I was going to take a part to the band saw. I would print a template and glue it on the peice of sheet metal and then trace around with a saw.

For most of my modelling needs, I will simply find a print in the scale I am working in and then match the physical parts up with the print. One could also measure the scale drawing and then measure the physical part they are working with until the two agree.

If you have a scale print but not in the scale of your model, you will have to do some math to alter what the true dimesions would be. Or you could take the image (if you have a digital copy) and scale it properly in a photo editing software.

Anything outside of basic math and photoediting software, you will need to have ComputerAidedDesign software. I think google has a free program, but I doubt it is anything like an Engineering CAD program.

However, when I have requests go to our modelshop, I will give them a print and they can make the part from it assuming my print is well done. If it is a complicated shape, they may need the Computer Drafted part to CNC the shapes, but for the majority of our parts, a peice of paper is enough.

Wow, that was too long of a post. It really is hard to describe this, someone needs to sit down with you and see what you need help with. The ability to take a print and make a part is sortof a learned skill, but it shouldn't be too hard if you have ok prints, some measurement device (as precise as you wanna go), and some basic math skills. You don't need to make templates for everything if you don't want to.

When you look at for example a side view and a front view of a tank on a peice of paper, can you imaging the model sitting before you?

I'd recommend the book "Model Design & Blueprinting Handbook" by John Lester. Very useful description of what you want to know.

Matt

And Matt could say what I wanted to say in 400 less words. Thanks for the recommendation, I have not seen this book, but it probably is a good read anyway.

1)
You need high-res drawings with dimensions or a scale bar then you have to use a CAD software which could allow you to visualize your raster images. Drawings without dimensions or scale bars aren't useful for you purpose.
After inserting your raster image in your drawing software, you'll be able to scale it using the dimension or the scale bar as a reference.
There are lots of sites where you can get useful raster images

Here some of them

http://www.smcars.net/forums/tanks/

http://www.the-blueprints.com/

http://www.mo-na-ko.net/letadla-planky.htm

http://www.airwar.ru/#

2) Actually there are LOTS of open source free or cheap softwares which you can install on your PC. You have just to make some internet research.
Look here for some of them

http://www.pure-mac.com/cad.html

You should be careful to choose a program which can allow you to insert, visualize and scale raster images.

Regarding the "transfert to styrene",when you retrace the outlines of your raster images, you'll be able to get the shapes which will be useful for your scratch projects. You can print them on paper to get the jigs which you'll use as a reference to cut your plastic sheets. Otherwise there are some companies which can make directly your parts using a laser cutting printer. You have just to send them your CAD file, they'll use as a template.

I hope that's is enough clear, and useful for you

cheers

PS. As far as I know, there are no cad softwares which can generate plan views from a raster image. You can't generate orthoginal views automatically unless you start from a 3d models

Hi
I appreciate your ambition, something I'm interested in myself.

I am learning AutoCad & Sketchup thru work as er personal development, & despite having some graphics & print background, IT makes my head hurt!

There is Googles' Sketchup, & there are plugins that will take a sketchup 3D .SKP & produce a flattened image, suitable for paper-folders, but I can't remember the name of the plugin & or if it is available for the MAC, (probably)

Keep posting your learning experiences, thogh & good luck!

I'll admit that I'm old but one thing I have found is that, while it's possible to do this stuff in CAD, it is time-consuming with a very significant and (in my case) prolonged learning curve. Using your Jagdpanther example for the superstructure/casemate if you can cut the top and bottom (things that are horizontal) out of plastic and glue them where they should be (I usually use 1/2" plastruct tubing as spacers) you can then fairly quickly measure the distances between edges and get your measurements that way. Draw them on a piece of paper and test fit and there you are. I find I can do that and have the bloody thing roughed in before I'd even have the original CAD design inputted.

Matt

Thanks for all the replies so far - I'll look into the recommendations and your help/comments are really appreciated.

Mufty

Hi Andy,

One thing that I would suggest is to try to avoid over-complicating the task. It's actually pretty simple.

That is, start with any known dimension on the real vehicle (for example, the diameter of the wheels), you can easily measure the same area on the drawings that you're using and then convert those drawings to a known scale (divide the actual dimension by the drawing dimension = the drawing scale).

Once you know the scale of the drawings, you can then take measurements from them, convert them to actual dimensions (the scale x the drawing measurement = the actual measurement) and then convert those actual measurements to the model's scale (actual measurement / the desired scale = the scale dimension).

This math is quite simple and is a good reason to keep a cheap calculator along with a note pad and pencil on your work bench.

In the absence of known actual vehicle dimensions, you can use a dimension taken from a model part (of the same vehicle, obviously). Multiply the model part dimension by the scale and the result is the actual vehicle dimension (or close enough for most model-building work).

If all of your working measurements are done in the metric system, then most of the calculations are easy enough to do "stubby pencil."

In so far as determining which lines on a set of drawings represent "true" dimension, all you need to do is to look for lines and planes that are perpendicular to the view. That is, as long as the drawing line is not representing a plane or line that is "moving" to or from the view (side, front, rear, top, bottom), then that line represents a "true" dimension that can be measured on the drawing and converted to the required scale measurement.

With some complicated angles, you might have to refer to up to three different views (ex: top, side and front) to find the "true" dimensions of all the side edges of the part that you want to replicate. But usually in at least one view (on a three- or four-view set of plans) the "true" dimension of any line can be measured. I often make a rough sketch of a part to use to record these "true" measurements onto as I'm working out the project.

(The exceptions are sometimes "compound" curves which can be hard to measure, but even those can be figured out eventially.)

But this is really all there is to it.

If you can use an X-acto knife and a straight edge to cut a part out of sheet plastic, then you have the skill to use a pencil and a straight edge to transfer the scale measurements taken from your drawings to that same sheet of plastic.

With an understanding of the simple math to convert measurements to scale and vice-versa, you can easily use plans from any source, with or without knowing the nominal scale of the drawings.

In fact, you will often find that the scale on a set of drawings has been published incorrectly, is actully inconsistant from one area or view to another, or that perhaps the drawings were not reproduced to the constant scale indicated. You will also find that there are very often conflicting dimensions on differnt published sets of plans and any kits that you're modifying or building.

In the end, you almost always have to make some compromises to any scratch-building project to accomodate these competing demands and information sources. (Even if you take the measurements yourself from an original, you often have to make compromises on how the actual parts are being made so that they will fit together and on any model being modified.)

Also, with this knowledge, you can scale vehicle parts from photos, and make up you own working drawings for new parts. (Just remember that the "scale" of the vehicle depicted in most photos changes across the image - unless it's a perfect side, top, etc, view - so all you need to do is scale the area on the photo closest to the part in question by using some known or claculated vehicle dimension as the base.)

You really don't need to use a computer program to do any of this for you. All you need are good rulers and clear drawings.

I will confess that I use a metric dial caliper to measure with, both on the drawings and on the sheet plastic instead of a ruler, but many very good scratch-builders just use a good ruler.

All of this sounds complicated to explane, but once you grasp the idea, it's all quite simple to do.

There are some "tricks" that will help when actually constructing the scratch-built parts to get perfect joints, etc. But in so far as determining the scale dimensions of the finished pieces, again, this it really all you need to know (or at least close to 99% - the rest is mostly a matter of experience and trial and error).

HTH,

Hey again Andy,

Here's a quick example of what I was trying to describe about having to refer to multiple views of the drawings in order to get all of the "true" measurements for a complex shape that's not all perpendicular to any one view.

In this example, say you want to replicate the upper rear side hull plate on an M4 Sherman tank.

You can see in the photo that it's a very angular plate - angular around its edges and it sits at angles both to the horizontal and the vertical.

To get the long dimensions, you need to refer to the side view drawing. In it, those lines are perpendicular to the direction of the view (from the side). However, the short end dimensions are represented by lines which are foreshortened in the side view, so you can't take those measurements from the side view.

For the front short end, you need to refer to the top view drawing. Again, in it, this line is perpendicular to the direction of view (from the top). Howver, the rear short side is still foreshortened in this view.

To measure the rear short side, you need to refer to the rear view. Note in the rear view how the long sides and the front short end are extremely foreshortened.



So, there you have it. This is how you can determine the actual dimensions of those problematic sloping armor plates.

You just have to visualize the actual vehicle and determine which lines are shown in their "true" length without any foreshortening in which drawing views. Combine these measurements taken from your various drawing views (maybe on a working sketch) to get the final measurements for your scratch-built part.

You will also need to project some right angle lines from the ends of certain key lines in order to bisect and plot adjacent lines to correctly get some angles right.



For instance, in the top view, you will note that the long side lines are parallel to each other. Determining how far forward or rearward one line is from the other will give you two points to plot the ends of the short ends ensuring the angles are correct. Where the ends points of these short lines fall on these right-angle lines will establish (in this example) how far apart the parallel lines are from each other.

(Edit: Oops! I should have drawn up the example using the side view drawing to show how to measure and establish the off-set. "Haste makes waste!" or "Do as I say and not as I do.")

Measure these off-set distances on the same view that gives you the true measurements (in this example from the side view). Again, in this example, you would draw a right angle line from the forward end of the inner long side line until it intersects the outer long side line. The distance from the point of intersection on the outer line to its forward end is the amount of off-set that you would transfer to your plastic sheet (once the measurements have been converted to scale).

So, how to make this part?



Layout the long outer side line first. Next, measure back from its front end the amount of the measured off-set. Plot a right angle line from that point.

Next, starting from the front end of this same outer side line, draw your forward short end line using a compass (or a scribe) set to its scale length. Where the compass intersects the right angle line is the second end point for the short front end line.

This same point is also the front end point of the long inner side line, which can now be drawn its full length and parellel to the outer long side line. Where these two inner and outer long side lines end are the end points of the short rear end line. Simply connect these two end points.

Again, this all much harder to describe and write than it is to do.

Thanks Mike

You're a superstar and thanks for all the effort you put into your reply. Terrific!

Cheers

Andy