Enlarging Drawings To 1/32

[MikeS]

I am wanting to enlarge some drawings up to 1/32nd scale from 1/48th. Actually the drawing are a little more like 1/46th or so. What is the best way to do this? Not worried about the math of it just the technical side. I don't have a scanner so does Office Depot or one of those type places have copiers/enlargers which will allow me to get to an accurate dimension?

 

Thanks,

Mike.

[ssculptor]

Well, first you should determine the exact scale of the drawing you have. Then you can go to a place like Staples or Office depot and use their self service copy machines. Nowadays these copiers have the ability to scale up items by percentage.

But you still need to know how to determine the scale you need. If you know the exact wingspan of the real plane you might first determine the factor for scaling the srawing up. Carefully measure the copy of the plans you have. Use a scale (ruler) that measures to the 1/64 of an inch. I use a magnifying glass to see details this small. Then divide what the wingspan should be in 1/32 scale by the measurement you have. That will give you the enlargement factor you need to feed into the copy machine.

Example. McDonnell FH-1 Phantom (the first Phantom) wingspan = 40 ft 9 in

Multiply 40 feet by 12 and add 9 to convert to feet to inches = 489 inches.

Divide 489 inches by 32 = 15.28125 inches = 15 9/32 inches. This is the wingspan of the 1/32 scale model.

Lets say your plans wingspan measure 10 5/8 inches (1/46 scale).

Now divide 15.28125 (15 9/32) by 10.625 (10 5/8) and you get 1.438. That is the enlargement factor you have to type in to the copy machine. If necessary round it off to 1.44.

However, if you know the plans are exactly 1/48 scale then you can avoid all the above work and just divide 1/32 by 1/48 and you get 1.5 as the enlargement factor. A 1/32 model is 1 1/2 times larger than a 1/48 model.

 

Gosh, wasn't all this math fun?

Enjoy,

Stephen

 

P.S. If all this math gives you a headache just tell me the plane on the plans and the measured wingspan as close as you can measure it. I'll do the math for you and PM the enlargement factor back to you so you can copy it your self.

[mattlow]

Mike

 

One bit of advice. Go to a decent reprographic shop. They are more likely to have well calibrated equipment which is less likely to distort the image as it is copied. A well used and abused machine in a 'non-specialist' outlet may introduce unwanted errors into your original during the enlargement process (most common being errors in the x and y planes which will squash or elongate the image).

 

HTH

 

Matt

[ssculptor]

Mike

 

One bit of advice. Go to a decent reprographic shop. They are more likely to have well calibrated equipment which is less likely to distort the image as it is copied. A well used and abused machine in a 'non-specialist' outlet may introduce unwanted errors into your original during the enlargement process (most common being errors in the x and y planes which will squash or elongate the image).

 

HTH

 

Matt

Mike,

Matt is correct. The copiers at the average Staples, etc. are set to give a very slight distortion in the Y plane. This is to prevent anyone from making fake money that may get past dollar changing machines.

Stephen

[LSP_Kevin]

Mike,

Matt is correct. The copiers at the average Staples, etc. are set to give a very slight distortion in the Y plane. This is to prevent anyone from making fake money that may get past dollar changing machines.

Stephen

 

Sorry Stephen, but this is one for Mythbusters. It's simply not true. Modern copiers actually print their serial number in "invisible ink" (detectable only using UV) on every page they produce, and it's that that is used for tracking illegal or illegitimate output. Most of the world doesn't even use paper money! (Aussie notes for instance are made out of plastic, with a metal strip embedded vertically.)

 

Any degree of distortion introduced in the copying process is not deliberate, but merely a by-product of their operating requirements and tolerances.

 

Kev

[Bruce]

Mike,

Matt is correct. The copiers at the average Staples, etc. are set to give a very slight distortion in the Y plane. This is to prevent anyone from making fake money that may get past dollar changing machines.

Stephen

 

a way to confirm that the drawing is getting blown up equally in the x and y plane is to draw two lines perpendicular to each other. on the lines, make a reference mark on the line. if the drawing is 1/48 scale and you draw a 4 inch line on each reference line, then when the drawing is 1/32 scale the two reference lines should measure 6 inches( 1.5 times larger). if they do then the copies is blowing things up eavenly in both x and y planes.

 

Bruce

[ssculptor]

a way to confirm that the drawing is getting blown up equally in the x and y plane is to draw two lines perpendicular to each other. on the lines, make a reference mark on the line. if the drawing is 1/48 scale and you draw a 4 inch line on each reference line, then when the drawing is 1/32 scale the two reference lines should measure 6 inches( 1.5 times larger). if they do then the copies is blowing things up eavenly in both x and y planes.

 

Bruce

Bruce,

That is a good test.

Thank you,

I seldom have a problem with scaling because I work in AutoCAD. There are several ways of playing with a drawing in AutoCAD to get the exact scale in both directions. But most of the modelers have to use what copy machines are available.

The next question is what degree of accuracy are we talkling about? How accurate will our scratch built model be? If the wingspan is off by 1/32 of an inch will anybody even notice? Does it matter? Everything we do in modeling in smaller scales is an approximation and compromise anyway.

I better stop now before I rile the exactitude guys.

Atcha all later.

Stephen

[abledog5]

Bruce, Stephen is right with his math. I build a lots of scratch models and my first tast ia to look up the correct length of the plane. Then like Stephens said figer how many inches you need from tip to end of the model. I go to Fed-x and tell them how long I need the drawing of the model. I usely run it off on there big sheets about $4.50 for the print. I have had good luck this way and it works great for me.

abledog5

[ruzlkampf]

Hello Mike, Nice avatar! You've already mentioned that you know the math and just want to know the technical side of reproducing drawings. I do this routinely,(uuuuhm, I think I re-scale a model drawing at least once a day. ) and one of my 'side-businesses is owning a reprographics shop. I think I know what you're asking, and want to know more than just how to re-scale a drawing. Shoot me a PM, and I'd be more than happy to discuss any questions on the technical side.

I've found that most drawings in 3 or 5-view aren't exact, and don't match up when enlarged and have to be cropped/edited/rotated blah-blah to get what I want. Also, depending upon the size of the aircraft,.....you may not want one HUGE 3-view drawing (which is costly and hard to handle) but individual sheets of each view as an example. Lines that are less than pencil-thin on a 1/72nd scale drawing get 1-2mm thick quickly when enlarged. I've got access to large plotters that handle up to 36 inch wide rolled media (black-white) and 5 ft. for color and reduce-enlarge in hundreths of % increments. Let me know if I can help you out, eh? I really enjoy doing this kind of stuff. Bruce mentioned Kinko's/Fedex, and they'll usually have the equipment like a scanner and large-format plotters that will do the job but a lot depends on the operator of the equipment. Some are better trained than others, and depending upon how many tries (and feet of paper) it takes to get what you want,.....cost goes up accordingly. Much depends on the size of the plane you want enlarged, and what media sizes/equipment the copy-center has available.

Fascinating hobby, playing with plans....and if you want to know more feel free to contact me. Later!, Russ

[LSP_Ray]

Because the printed drawings may be off-scale, and very possibly of a slightly different scale in each direction, the most accurate way to do it is to scan it to a file then import it into a CAD program. Then, by knowing the correct actual dimensions in each direction, you can manipulate the drawing to fit, and print or plot your drawing out at the correct scale. Of course, you need the scanner, CAD software and a printer big enough to print it! Failing any of that, as long as the original drawing is not too distorted, you will get close by doing what the others have suggested.

[MikeS]

Thanks all very much for the information. Many points have been brought up which had NEVER even crossed my mind. The drawings I was going to scale up have actually been replaced by a better set but non the less still have to be re-scaled. Nice thing is I have these drawings saved on my computer. I am going to think about things a bit before making a decision.

 

Mike.

Man - this is a great board!

[ssculptor]

Thanks all very much for the information. Many points have been brought up which had NEVER even crossed my mind. The drawings I was going to scale up have actually been replaced by a better set but non the less still have to be re-scaled. Nice thing is I have these drawings saved on my computer. I am going to think about things a bit before making a decision.

 

Mike.

Man - this is a great board!

Again, may I ask, when you make the model itself, how close to the actual meaurements will your physical model get? How thick a line will you use on the drawing? In other words. I am not talking about 100% accuracy. I see model building, especially scratch built modeling, as being a certain percent of accuracy. Maybe 99% accurate dimensions? 98%? You are making this model by hand, you are not using a CNC machine that reads off of computer drawings that are accurate to eight decimal places.

So, my advice is to relax and just get as close as you can in accuracy and enjoy the build.

Unless of course, you are so anal retentive that you must drive yourself nutz trying to get absolute 100% accuracy .

Also, when your model is completed, remember that if any legally insane person comes by with a large vernier calipers and starts to measure your model, you are entitled to shove that tool up his..... oops, this is a family oriented forum.

My final point about accuracy, has anybody investigated the differences in an aeroplane's wingspan when the aircraft is on the ground in +120 degree F temperature with the sun beating down so hot the plane's surface can actually fry an egg, and when the same airplane is flying at its maximum altitude where the temperature is -40 degree F?

So, enjoy your modeling my friend, but take care that your hobby does not become an insane compulsion. I've known guys who gave up their model making and went back to work because after the stress of the hobby the guy's job was so relaxing.

Stephen

[stevegallacci]

A simple but important thing to also remember is that the exact reduction or enlargement might not be just that, or get you where you really want to be, like if the original drawing wasn't really in scale X and the enlargement wasn't accurately up to scale Y. Much better to have key dimensions or a large scale bar already calculated to the final size it is suppose to be and work towards that.

I was stuck in a project for someone who had patterned a bunch of parts off of copies of drawings, or worse, copies of copies, none of which were ever checked for dimensional accuracy, only the presumption that the reductions were right. All the work had to be tossed because they not only were not to the intended scale, but the various parts didn't match each other due to repro errors in the copies of copies. The drawings didn't include any meausrments, he had drawn, even traced, the parts directly off a specimen, he never dimensioned the work. And as I had only copies to work from, I had to remeasure the specimen to find out what was really going on.

[Out2gtcha]

Maybe this has been mentioned in the above comments...im just on call this weekend and am running on 5 hr sleep in 45 or so, so I didnt go through all the txt....

 

I usually just go by percentages.........and then just have someone scal them up for me from there. This is a handy chart I whipped up that helps me:

 

 

Cheers,

Brian

[Cees Broere]

That's a handy table Brian,

 

Could have used that one when upscaling the Handley Page 0/400 drawings. I used a

table from the Internet but that one was wrong (or I didn't check it well enough )

 

The 0/400 fuselage is now scale 1:28!, but it's nicely big.

Cees