Searching around the internet you can come up with plenty of woodworking plans like tables, desks, birdhouses, bookshelves, dog houses, doll houses, etc. So how do you know if it is a good plan? Well, no matter the type of drawing, a good, usable drawing has a few things that you should look for:
1. Are the dimensions and notes readable if drawn by hand? There are some pencil drawn illustrations out there. Some good, some not so good and unless the drafter took care to make his lettering plain, there could be a problem as you try to build from it. The drawings should very clearly show dimensions and notes in such a way that it leaves no question as to how they relate to the subject.
2. Do all the views of the drawing look like they belong to the same piece? In other words, the quality of the projections will many times tell you if there was thought put into the design or if somebody was just doodling.
For instance, say you have a table top that measures 24 inches by 36 inches but the top looks like a square instead of the rectangle it should be. In other words, it’s disproportionate. This can really cause confusion. Actually, the best drawings were drawn in a CAD (Computer Aided Drafting) program or on a drafting board with some controls over the images.
3. Is there a cut sheet attached to the drawings? A cut sheet takes the project apart and illustrates the various parts of the piece with specific dimensions for each piece. This is very important as it will cut your trial and error time down to a minimum.
4. Not always necessary by the way, but did the one making the drawings give specific notes about what types of fasteners and glues to use? How about special joints needed to make the project sturdier. This is a big plus.
5. The really good drawings have an exploded view that shows parts placement. This is where the drawing is made in an isometric (3D) view with the parts out just beyond where they fit together. Another good example would be a finished photograph that shows most or all of the thing you are building. This helps you get a better feel for the overall project.
Hey, there are very few plans that are perfect. Whenever a human hand is involved in the creation of something, you have to expect some omissions or errors from time to time. But sloppy drawings can inspire sloppy end results if left unchecked.
Tim Davis has created a very complete course on learning to draw mechanical drawings in a CAD program at http://mechanicaldrawing.us