by Mfezi » Sat Mar 09, 2013 1:28 am
Here is what I do:
Getting the parts on paper, one of two methods:
1a) Copy the plan and cut out (just like Mitch does). This works well if all the parts are nicely grouped on the plan so you only need to copy a small section of the plan. Always check your copy to make sure the copier didn't stretch the parts.
or
1b) On some plans, the parts are scattered all over the plan and you would have to make a lot of copies with just one or two parts on each. In that case I use either tracing paper or velum, and trace the part directly from the plan with a pencil by hand. I typically use a couple of small pieces of masking tape to make sure the tracing paper doesn't slip or move while I trace. I continue doing this until I have all the parts drawn on the sheet of tracing paper / vellum. This also works well on some plans where only half of the former is drawn - you draw one half, then flip the tracing paper over and then complete the other symmetrical half of the part on the other side. I then copy this velum to normal copier paper, especially if I need to make multiple copies of a given part (like wing ribs). If a one-off, you can skip that step and cut out from the tracing paper directly.
Getting it on the wood:
2) Glue it on with the cheapest water soluable glue stick you can find. Glue sticks work well, because it is a "dry" glue, so the paper doesn't deform when you stick them on. Some glue sticks have a more permanent glue - you may have difficulty getting the paper off the part afterwards, so I recommend just using the cheapest ones you can find.
3) Cut the part out with a sharp scalpel. I like to cut it just very slightly oversize and then trim perfectly with a sanding block. If you can cut very accurately, just cut it exactly to size from the beginning. With really thick wood (the stuff I use for radio control models for example) I always cut oversize and then true up with a sanding block, as I find it very difficult to cut perfectly square on something like 1/4" balsa. In the case of free-flight models it is less of a problem as we seldom use anything thicker than 1/16" or 3/32" balsa. When cutting from plywood or another hardwood, I cut it oversize with a scroll saw and then use a disk sander to sand the part perfectly to shape.
Getting the paper off the wood:
4) Lightly wet with a spunge dipped in water, and leave for about 30 sec to a minute for the water to soak into the paper and wet the glue from the glue stick underneath. You can then peel the paper off, usually without leaving any residue. If you were over zealous with the glue stick, some residue might be left on the part in which case you can just wipe it off with a wet cloth. If the wood got slightly wet, make sure you leave it flat to dry so it doesn't warp, but I never really had this problem.
There are other methods to transfer the shape to the wood, but I have used the above for scores of models over the years - sometimes on radio control models with literally hundreds of parts and I always get consistently accurate parts this way. It is probably not the quickest, but really accurate and consistent. It also leave no marks on the wood afterwards, resulting in builds that look very "clean".
B.A. Broughton
