Back to Basics - Measuring and Cutting
A while back one of my blog readers commented that I had said in a tutorial, "you know how to cut and measure your piece..." However, she said that she had never really been taught and found that ALL her cuts went askew. She asked if I could give a rundown on exactly how to cut and measure, including any tips or pointers we should know.
I'll describe here what I was taught in the days before hobby saws, laser cutters and routers. As with everything I write, my tutorials are not gospel. Please take from it what is useful to you and discard the rest.
Basics of wood
First of all, you need to know a little bit about the wood you're using. There are two groups of wood – hardwood and softwood. This doesn't refer to the physical properties of the wood, just whether the tree from which it came is an angiosperm [a flowering tree] or a gymnosperm [a tree that produces 'naked' seeds]. For example, Balsa wood comes from flowering Balsa trees, and is classed as 'Hardwood', but is physically soft. Similarly, Pine wood comes from non-flowering pine trees, and is classed as 'Softwood' although it is physically hard.
A lot of model makers use wood sheets from timbers such as Basswood / Linden, Obeche, Spruce and Jelutong, because they are relatively inexpensive and are easy to work.
When you buy wood sheet, you want a piece that isn't warped in any way and is free of knots.
On the whole, and certainly in England, hobby wood sheet tends to be cut from a tree 'quarter-sawn'. Basically this means that it is cut at right angles to the growth rings of the tree. If you stood a length of quarter-sawn wood upright on it's narrowest end, the grain (which is the darker lines running through the wood) runs pretty much vertically, top to bottom. There are exceptions to the rule but that's a whole other tutorial.
The direction of the grain matters in woodworking for three main reasons:
You've heard the phrase 'Going against the grain' before, yes? It refers to making life harder for yourself by going against the natural direction of something. It's exactly the same with wood.
It is easier to make a cut that runs 'with the grain' than 'against the grain'. This is because the grain (the darker lines) are lots of tough, cellulose fibers held together with a weaker (light colour lines) Lignin. It's much easier to break the Lignin than the fibers.
When you rub sand paper 'against the grain' the fine glass on the paper tears at the fibers of the wood and makes them stand up so that the surface looks and feels rough. By sanding in the direction of the grain, the fibers lie flat in a natural direction so they appear and feel much smoother.
Because the cellulose fibers are the strongest element of the wood, they also are the strongest element of your furniture, both miniature and life-size. So always have the grain running in the same direction as the longest length of your design.
With the grain
Against the Grain
Now obviously you can't construct anything without making any cuts against the grain. So to make your life easier, make the longest cuts with the grain and the shortest cuts across the grain.
Plywood (wood panel manufactured from at least 3 sheets of wood) is OK for building houses – it is stronger than single sheets, as each sheet is glued with its grain at right angles to the adjacent layers for strength. When cutting it, work with the grain that is visible on the outer layers of the sheet. However, I would never suggest using plywood for furniture because it doesn't cut well and the grain is huge.
If you don't buy anything else invest in a good, steel ruler and an engineers' square.
You may wonder why I haven't suggested a carpenters' Try Square since we're working in wood and I'll tell you why. As with all trades, there are cheap and nasty tools and super expensive ones. The engineers' squares are milled to an exact tolerance, making them the most accurate of squares...no matter how much you pay.
The first thing I do before I even pick up a saw is to establish a straight edge to work from. Just take your steel ruler, hold it onto one edge of the wood and hold it up to a source of light.
Wood and ruler held up against a window
If you can see any light between the ruler and wood, then the edge isn't true and all measurements from it will amplify the mistake. In my experience, most craft wood is dressed well but it pays to check. Once you've established your straight edge, you can measure from there.
Using an engineers' square
To get an exact right angle, place the thicker part of the engineers' square against the straight edge of your wood. If you draw a pencil line along the thinner part of the engineers' square, you now have 90° --- the basics for any box structure.
This may not seem important but keep your pencil sharp. I use a mechanical pencil with a fine lead so that my measurement marks are precise.
Sawing and measuring
Once you've established the straight edge of your wood, you can pretty much work everything from that starting point. Next thing to do is to saw against the grain to establish the next straight edge which will be at exactly 90 degrees to the first straight edge. If you don't think you can saw in a straight line then the engineers' square is going to become your best friend.
As an experiment and to prove a point I've enlisted the help of my mate Ian, who is an electrician and knows very little about joinery. He knows even less about miniatures so that's why he's gripping the tools like they're gonna bite him =0)
I've marked a line across the wood with the engineers' square (as explained above).
Ian's holding the engineers' square against the straight edge and has placed it right up to the pencil line. He is using a gents or hobby saw. I've shown him how to hold the saw so that the blade butts up to the straight edge of the engineers square. This stops the blade wandering.
Gents saw (Amazon.com)
Let the saw do the work with long strokes. You don't have to put much pressure on the saw. The teeth are extremely sharp and will cut through craft wood in no time.
The picture above is the wood after Ian has cut it. He didn't have to sand it and still got a perfect right angle by using the engineers' square as a guide.
Now you can measure your next cut.
I've seen this countless times before and it ALWAY knocks your measurements out. When you are measuring, put something square at the end of the wood and the ruler. Make sure the ruler is against a straight edge. If you put it on top of the wood, chances are you'll move ever so slightly. Even a millimeter is enough to knock the whole thing out.
Use your pencil and make a small mark at whatever length you need. Again, use the engineers' square held against the straight edge to draw the next line horizontally across the grain. You get the idea? Of course you do =0)
If you use the technique described above, you will reduce the amount of sanding you have to do.
I always have a collection of wooden building blocks that I use for sanding. Just use some double sided sticky tape to stick different grades of paper to the block. If you use sand paper in your hand, you naturally move in an arc, putting more pressure at your finger tips and at the heel of your hand. So if you were sanding a flat edge, you would end up with curved corners at either end. Always use something flat to wrap/stick your sand paper to.
As a rule of thumb, if you have more than 3 millimeters of waste wood to get rid of, use a saw to cut it away. If it's less than 3 millimeters, use sand paper.
Always sand to a pencil line. This guides you and helps to keep the sanding even.
Well I think that's about it. The only other thing I can suggest is to read up on blogs and ask questions. There's a great community out there who are happy to help. I would suggest books to read but I'm the sort of person who can't absorb information from a page. I have to see it done and then try it for myself. Oh, and Youtube has a wealth of 'how to's' so it's also a good place to go.
Um...maybe one last piece of advice for happy miniaturing. Don't ever compare your work to someone else. Your work is unique and all you should ever strive for is making yourself happy.
Have a great day