ORIGINAL: Dsegal


How To Create Patterns on Wood

Layout the pattern directly onto the wood.
Use a pencil, straightedge and drafting tools such as a compass and French curves. This is simplest with straight line shapes.

Pin*****s
Place the plan atop the wood and use a pin to make a series of holes through the plan and into the wood. Remove the plan and then "connect the dots" on the wood. This seems a low-tech method but in practice is very accurate, especially for curves.

Tracing shapes
Tracing paper
Tablets of tracing paper are available from CVS and Staples stores. Place the paper over the plan and trace with a pencil or pen. The pattern can be fixed to the wood by applying a glue stick to its back or using a removable-type spray cement. The pin***** method can be used or you can simply cut directly through the paper into the wood. This is a fragile pattern not intended for multiple parts. For greater durability the tracing can be glued to light card stock and then cut out for a template.

Mylar drafting film
This is a sturdy plastic with a roughened surface to take pencil and ink.A brand called "See-Temp" is sometimes advertised in modeling magazines. The mylar is easily cut with scissors or knife and can then be placed on the wood and traced around the edges.

Photocopying
This sounds like a great way to go but there is a hidden danger in the inability of the ordinary office copier to make an accurate same-size copy. If you use a copying machine first place a scale on the glass window and make a copy. Then place the scale alongside its photo image and measure the discrepancy. Even a one percent error means you will be off by 1/4 inch over 25 inches. Try to adjust the copying magnification on the machine to get the most accurate result. And if you come back and choose another machine at the print shop you will have to do the calibration test all over again.

Once you have made the photocopy it can be copied to the wood by pin*****s, cutting through the paper or transferring the ink onto the wood.

Ink transfer
Tests must be made for any brand of copying machine due to variations in their technology. And practice on scrap will avoid waste of good wood.

Heat transfer
The common process employed by copiers uses heat to fuse a powdered toner onto the paper. By placing the photocopy face down on the wood it may be possible to transfer the image, in reverse, onto the wood. Use a household iron for this.

Solvent transfer
The toner may be soluble in thinner such as lacquer thinner or dope thinner. Place the copy on the wood, image side down, and then dip a cotton swab into the solvent. Don't use too much liquid. Then draw the swab around the outline of the part and while pressing the swab down.. The liquid will briefly make the paper transparent so you can see what you are doing. Then lift the copy off. It may be possible to repeat this if enough toner remains on the paper.

Rib templates
When many identical pieces such as wing ribs must be cut it is useful to produce a rigid template. Lite-ply works well as it is cheap and easy to cut.. The pattern can be transferred from a photocopy by using a solvent-dipped swab. Then cut out the template- an electric scroll is perfect for this. Sand the edges to the final shape. If desired, the edges can be hardened by dribbling thin CyA adhesive. Place the template onto the balsa and draw the knife around the edges. Finger pressure is adequate to hold the template in place but pins can be pressed through the template to secure it. Note: omit the spar notches from the template so that the cutting movement with the knife will go more smoothly. Afterwards, the ribs can be stacked and pinned together so that the spar notches can be marked and then cut out