Enlarge Model Airplane Plans for Free

One of the challenges with building a model airplane from a smaller sized set of plans, typically received over the internet, is getting the full size plans produced.  Read on for a simple and easy method to enlarge model airplane plans for free using the built in tools with any PDF file.

1911 Fokker Spin radio control model airplane in flight

1911 Fokker Spin in flight

In the old days, when offering construction plans was part of the business model of the model aviation press, the various magazines used a blueprint machine that printed out full size sheets with the hand drafted plans. These plans were ordered through the mail and the model built directly over the drawings. It was not uncommon, as late as the mid-1990s, for industry leaders like RC Modeler magazine to include up to three airplane construction articles and their associated plans in a single issue.

Those days are long gone with the advent of ready to fly model aircraft. Instead, there are available today a varied range of quality model aircraft plans that designers create with popular and easy to use Computer Aided Design (CAD) programs such as the one I use, TurboCAD.

The drawings produced by these CAD programs are top notch. The difficulty that builders face is the plans can be easily printed out on a home computer with normal 8.5” by 11” paper. But one would need access to a large plotter to produce a full size plan, something that most people cannot easily do.

Spin front view showing thread rigging wires

Spin front view showing thread rigging wires

A work around that I have used in the past is to go to a commercial graphics store such as FedEx/Kinko and use one of their scanner-printer machines. These remarkable devices take a drawing on a regular size piece of paper and scan it into memory. You then type in an enlargement ratio. The printer prints out an enlarged version of the scanned sheet that you can use as your full size model plan. This approach works fine. However, you need to find an office store that has one of these scanners and the cost of the scan can be a bit high.


There is another simple method to produce full size plans at home on your personal printer, using regular 8.5” by 11”paper. And best of all the process is free! I’ll describe how I did this with Sheet 1 of my Fokker Spin plan.

I designed the Fokker Spin using TurboCAD. This indoor flyer uses the ParkZone line of radio control electronics and has a 28” wingspan. The Fokker Spin plan set is available here and comes in three sheets. To follow along with this demonstration, please download the Spin’s sheet one drawing here Fokker Spin – PDF Sheet 1.

Fokker Spin nose

Spin prototype nose section

One nice feature of TurboCAD is the ability to save plans directly into an Adobe PDF (Portable Document File) format. All of the precise TurboCAD lines and dimensions are faithfully reproduced in the PDF version. The advantage of a PDF file is that anyone can access this file with the free Abode PDF reader. This is not the case with the TurboCAD file of the Spin plan (included with your order, by the way) if you do not have a CAD program installed in your computer.

Once you have opened the Spin fuselage side view PDF sheet go ahead and select the Print dialog box. You will notice the “Page Size & Handling” buttons about half way down. To print the plan on one piece of paper you would click on the “Size” button and select “Fit” to make the print out fill the whole single page.

The objective is to make a full size plan. The PDF print dialogue window has a neat way to accomplish this by using the “Poster” feature. The Poster feature allows you to enlarge the original file by whatever percentage you desire. The print function will automatically produce individual “tile” pages that you can tape together for a full size plan.

Top view of the Fokker Spin RC model

Top view of the Fokker Spin RC model

This is easy to do. First, you’ll need to determine how much to enlarge the plans. I have a six inch ruler drawn out on each sheet. You will need to measure the ruler on the single page (which will be less than six inches in length) and determine the ratio needed to enlarge this to full size. As the enlargement ratios vary with each sheet I’ve included the correct ratios on each sheet. For this example I will enlarge the plan by 150%. This will result in four tiles to produce sheet one of the Spin plan enlarged to 150%.

To do the enlargement of a PDF file click on the “Poster” button. Add a “Custom Scale” ratio of 150%. If needed, click on the Poster button one more time to ensure this command is accepted.

Once this command is in place you will note the print thumbnail drawing showing the size of the final print out (22 x 17 inches in this example) and dashed lines showing the individual page tile arrangement. A handy feature under the Tile Scale is the “Cut Marks” check box. Go ahead and use this, as light marks will print out on the tiles showing correct alignment. Select print and the tiles will come out on your printer. Tape the tiles together as shown in the thumbnail to create a full size copy of your plan.

This is a convenient and inexpensive method to produce full size model aircraft plans from a single sheet PDF file. The screen shots and pictures below provide more detail on the process.  Give it a try, and good luck with your future plans built radio control aircraft modeling projects!

Print window of the Fokker Spin plan from a PDF file

Print window of the Fokker Spin plan from a PDF file

Print page of the Spin PDF file showing normal, single page ("Fit") of Sheet 1 of the Spin plan

Print page of the Spin PDF file showing normal, single page (“Fit”) of Sheet 1 of the Spin plan

Spin PDF Print page showing 150% enlargement (Tile Scale) and "Poster" Button - Note four page divisions on thumbnail of the printed plan

Spin PDF Print page showing 150% enlargement (Tile Scale) and “Poster” Button – Note four page divisions on thumbnail of the printed plan

Sheet One page print out of the Spin PDF plan

Sheet One page print out of the Spin PDF plan

150% enlargement of the Spin plan showing the four tiles, before taping together

150% enlargement of the Spin plan showing the four tiles, before taping together

Spin Sheet 1 on a single page (left) and 150% enlargement (four tiles) at right

Spin Sheet 1 on a single page (left) and 150% enlargement (four tiles) at right

Author: Gordon McKay