First question- Start with a simpler scratch project, and work your way up. I’d start by scratch building a trailer. Now, wheels are hard to make from scratch unless you have a lathe. So find a kit that has wheels and maybe axle, then scratch the rest of the trailer. I’d pick a kit for a car from the thirties, which mostly had solid front axles- say a thirties vintage Ford or Chevy. Trailer could be built from wood or styrene.
For converting plans- simple math. Use a calculator for help. Make a fraction. Put the scale of the existing 3-view plan on top (numerator) and the scale you want to build on bottom (divisor). Carry out the indicated division. If result is greater than one, you are scaling up. If less than one, you are scaling down.
Example. Say you want to, as you mentioned, build in 1:72, but the drawings you found are 1:48.
Fraction is 48/72, or 0.67, So you set the copy machine to 0.67 and it will reduce it to the size you need. Keep the original, or make a copy of it also, in this case, because when you scale down the original, larger drawing is often much easier to see, but you take measurements off of the scaled plan.
Lovely advice, Don. Thanks for sharing the conversion examples. I’m sure it makes it so simple nowadays with copy machines having such detailed enlarging/reduction facilities.
I love working with paper card and some of my models of WW-I aircraft are made this way. Love the way paper lends itself to making the hidden ribs and outer doped fabric with indentations from an old ball point refill to get the shape of the ribs and structures behind the fabric show realistically on the wings as well as the fuselage and other control surface structures.
Don offered great advice since nothing comes in as handy as plans to scale. But one thing I learned (even if I’d already read about it,duh!) is to watch out for some shrinkage during the photocopy process onto paper. I first set the machine to what the 'math’shows but then also use a scale ruler on a known length to verify the results. This almost always shows a need to adjust again.
I did a project in high school where I scratch built some models. My dad had an instrument that you traced the plans with, and while you did, it would re-draw them on another sheet to the scale you set. I don’t remember what it was called, and they may not even make it anymore! But it worked really well.
I realized in looking through the thread that no one had spent much time on your question of scaling plans. First, you need to know some major dimension on the original. Sometimes the scale drawings are dimensioned. For an ambulance probably the most important number would be the wheelbase- the distance from front axle to rear axle. Lets say it is 144 inches on the original. Now, for 1:72, you would divide that number by 72, getting 2.0.
Now, measure that distance on the drawing you have. Lets say it turns out to be 3 inches (that by the way would say your drawings are 1:48, since 144 /48 is 3.0. So you now need to rescale the plans so the wheelbase is 2 inches instead of 3, or reduce it to 2/3 of current size. I’d use a scanner to scan the plans, and a photo editor program to “resize” the drawing by 0.67, or 67%. You do not need to buy something expensive like photoshop. There are two good shareware programs, GIMP and Irfanview (do a google search to find them).
Also when I plan projects sometime the plans i acquired not detailed enough i breakout the old school pencil, paper and ruler to draw the plans to scale using the proportions described by Don.
You are right on with your questions. Now , as to the pantograph that was mentioned . I have worn out my share of them . I now get them in the coloring / craft section of HOBBY LOBBY. CRAYOLA makes a fairly good plastic one and I did see a really good one , carded in school supplies at OFFICE MAX .
I find , without question this tool outworks and outdoes ANY other tool for scratchbuilding purposes . The math DON gave is right on , and there are also good SCALE rulers available through a company that advertises in FSM . tankerbuilder
I started with this, just plasticard and a spare pair of wheels and tyres. I used no plans, just saw a picture and drew it onto a piece of paper with a car model next to it! …
No , common sense isn’t common , it just cost’s more . HE ! HE ! I like your little teardrop although I am trying for a motorhome in 1/25 with three slides on an AMT -AMERICAN- LAFRANCE ladder truck chassis I will try to get pics to here somehow . Tankerbuilder.