This is the first of our tutorial blog posts. Since 2010, we have focused heavily in both puzzle making and intarsia. We have developed a lot of useful tips and techniques and we would like to share that which we have learned. This basic guide should be enough to take you from start to finish for most simple puzzles. Other detailed posts will be forthcoming. Please add your comments and questions as they will ultimately shape future posts.
The style of puzzles that we make are often referred to as free-standing puzzles. This basically means that they are able to stand up freely on any flat surface without the need of additional support. They are two sided and are usually completely interlocking. If you want more visual examples, take a gander at our free-standing puzzle gallery. For this post, I will only be referring to free-standing puzzles. The only tool that you will need to make one of these puzzles is a scroll saw. Of course there are many tools to make the start to finish process easier and save a bit of your sanity, but they are not necessary.
Before you make a single cut, you need to know what you will cut with. Scroll saws can use either a pin end blade or a plain end blade. For the sake of puzzle cutting, avoid pin end blades all together. They are much thicker which makes intricate cutting and tight curves near impossible to cut accurately. Always use plain end blades when cutting puzzles.
The next thing to consider is the type of plain end blade. They come in a variety of different sizes and styles and there is no real answer to, "What is the best blade?" Every scroller has their own personal preference. For blade size, I would recommend either a #5 or a #7. When you cut the puzzle pieces out, the kerf line is just the right size to allow the pieces a little wiggle room to slide apart easily but not too much to detract from the appearance of the puzzle. These sizes also work well for a large variety of wood species and thicknesses. As for the style, since the puzzle is a two sided project, it is very useful to have a reverse cut blade of some kind. This reduces the amount of tear out on the bottom of the project and requires less sanding in the end (always a good thing!). There are a few different types of reverse blades out there. Try a few out and stick with the one that seems to work best for you.
So now that you have your blade all picked out, there is one last thing to do with the blade before cutting and it is perhaps the most important. Make sure that the blade has a perfect 90 angle to the table. If its off even by a single degree, the puzzle pieces will cut at an angle and may not fit together. This problem is very time consuming to fix (if it can be fixed at all) and is also the most common issue. Angled cuts can still happen with a 90 degree blade which I will cover in a future post.
One of the great things about using a scroll saw is that you can use wood that would otherwise be unworkable. Twisted boards, cracks, knots, and other board defects, while annoying, can generally be worked around. However, it's best to avoid these defects until you become very comfortable with your saw.
The wood you select should be surface planed on both the top and bottom. The sides can be left rough. Having a nice smooth bottom will prevent the board from wobbling, decrease vibration, which reduces the chance of angled cuts and blades breaking. For beginners, I would recommend a softwood to practice cutting on such as cedar, cypress, or pine. Once you get the hang of cutting, try out some hardwoods such as cherry or maple. When making puzzles, its best to use hardwoods. Softwoods like pine are too fragile and the pieces are more likely to break.
You have your wood and blade selected and now its time to cut your puzzle out. There are a number of different methods to transfer your pattern onto wood. I will go over the method I use. It will save you a lot of time if you sand the top and bottom of the board prior to pattern placement. A brief 220 sanding is generally sufficient. Take your paper pattern and cut out about 1/4" from the puzzle outline. Then cover the top of your board with a layer of blue painters tape. The tape serves two purposes that saves you a lot of time. Most importantly, it greatly reduces the chance of burning. Sanding off burn marks is very time consuming. Place your pattern on a piece of cardboard and use an adhesive spray to spray the back side of the pattern. Then place the pattern on the board on top of the tape.
The other benefit of using tape is easy removal of the pattern. Without the tape, the pattern would be adhered directly to the wood. If you manage to peel the paper off, you will be left with a sticky residue from the spray. You would have to clean and re-sand the top of each piece. Painters tape peels off easily leaving no sticky residue and the paper pattern comes with it. Now its time to cut the puzzle out, do some touch up sanding, and use the wood finish of your choice.
That covers all the basics on puzzle cutting. Now all you need to do is practice. If you have any questions, just send us a message or leave a comment below.