3 Bandsaw
3.1 Bandsaw Overview
The bandsaw is a relatively simple machine to operate, but has a huge range of capabilities. Its name comes from the cutting blade, a continuous band of metal that rides on upper and lower wheels inside the machine cabinet. Bandsaws are typically referred to by the diameter of their wheels; shown above are a 14” and a 16” bandsaw. Larger bandsaws have larger cutting capacity in both their throat and height (board width and thickness) and are designed for heavy duty work with larger motors. Bandsaws are most commonly used to cut curves and irregular shapes, but can also be used for straight cuts.
Upper and lower guides keep the flexible blade aligned and supported. The lower guide is found below the work table. The upper guide is part of a blade guard, which is raised and lowered based on the thickness of the material to be cut.
Bandsaw blade widths can vary from 1/16” to over 1”. Common woodshop sizes are often between ¼” and ½”. Thinner blades are capable of tighter radii, while wider blades cut straight lines better. Wide blades ¾” and up installed on large bandsaws are best used for resawing (cutting a board on edge into thinner boards). Straight lines can be cut easily by installing a fence on the bandsaw table to push the material against, or working with a sled or miter gauge in the work table t-slots.
In addition to cutting curves accurately, bandsaws have small kerfs (the amount of material lost during a cut as sawdust). This means less material waste. Also, because the bandsaw blade travels vertically, pulling the material down into the work table, there is virtually no chance of kickback (when the workpiece is thrown backwards towards the operator). Because of the lack of kickback hazard, the bandsaw is a great choice for the first cuts made on rough-sawn lumber. Bandsaws can safely handle warped lumber that is not yet flat or straight, and you can quickly learn how to freehand a straight cut without the fence.
Because it does not leave a smooth surface, the bandsaw is rarely used for final surfaces, unless you desire texture in your final product. If used for contour lines, the cut surface is sanded smooth afterwards. If cutting joinery like solid tenons, the cut surfaces are not seen in the final product, and the rough texture is not an issue.
3.2 Bandsaw Operation
The first step at the bandsaw is adjusting the height of the upper blade guide to clear the workpiece by about ¼”. Keeping the upper guide low is safer, as less blade is exposed. Keeping it low also ensures a more accurate and controllable cut as the blade is better supported. Sometimes, depending on additional bandsaw fixtures, this distance may have to be greater.
Layout all cuts before stepping up to the bandsaw. For more complicated operations, number the lines in the order they should be cut. Keep in mind the bandsaw’s kerf and make a small tick mark on the waste side of the line. Depending on your cut, it’s usually best practice to layout lines and cut directly alongside them. If you cut your layout line from the material, it’s hard to judge how accurately the cut was.
Odd shapes and small pieces must be held safely with jigs, sleds, or wooden parallel jaw clamps. In general, if the piece is smaller than a deck of cards or palm-sized, it should not be cut on the bandsaw. Round pieces must be carefully supported; the blade can grab the wood and spin it out of your hands or pull you towards the blade.
You should never make a cut where the stock is held unsupported off the work table. Very effective and safe setups can be created by hotgluing or pin nailing scrap wood to stabilize the workpiece for compound cuts.
- Check the width of the blade and make sure it is the correct type for your cut. Make a test cut on scrap if you are unsure the installed blade can cut the radius you need to.
- Plan your cut. Always make short cuts before long cuts, make straight cuts before curved cuts. Break long, complicated cuts into shorter cuts.
- Look at your layout line and ensure that it will fit in the throat of the saw throughout the cut. Sometimes you need to redraw the layout lines on the opposite side of the stock.
- Raise or lower the blade guard to ¼” above your workpiece.
- Take the cutting position, right-hand operators should face the blade standing slightly to the left. Guide stock with your left hand, applying pressure with your right.
- Start the saw and wait for it to come to full speed before cutting.
- Complete the cut and turn off the saw. Use the foot brake if equipped.
DO adjust the blade guard to within 1/4” above the stock’s thickness.
DO keep a push stick within reach.
ALWAYS allow the blade to come up to full speed before entering a cut.
DO be extremely careful when finishing a cut. The blade tends to “pop” out of the end quickly; there is no resistance to the force being applied, and your workpiece can move forward suddenly.
ALWAYS keep fingers a hand’s width from the blade. Use a push stick when necessary. NEVER line your fingers up with the cut; keep them to either side.
ALWAYS keep support under the blade. NEVER attempt to hold stock above the table by hand.
DO feed at a slow and steady rate.
DO use the brake if equipped. Apply gently, DO NOT jam or stomp on the brake.
DO NOT clear dust or debris while the blade is running. ALWAYS ensure the blade is completely stopped and power is off before clearing the table. The bandsaw wheels are large and heavy, and there is a lot of momentum keeping the blade moving even when the power is off.
DO NOT back out of a long or curved cut under power. The blade can break or jump track. Hold stock with one hand and shut off the machine. Once the blade has stopped, back the blade out from the cut.
DO NOT force the blade into too tight a radius. LISTEN to what the saw tells you, a squealing change in pitch means you are pushing the limits. Make relief cuts or drill a relief hole if the radius is smaller than the blade will allow.
DO NOT cut faster than the machine is designed for. Let the blade do the work.
Video: Basic Bandsaw Operation, Part 1: Straight Cuts
Video: Basic Bandsaw Operation, Part 2: Contour Cuts
3.3 Making A Push Stick: Cutting Out The Shape
As explained in 2.3, drilling or bandsawing can be completed first. Carefully consider the process of cutting out the shape. The top curve or the cleat can be cut first. However, when cutting the cleat, you must make the short cut first to avoid backing out of the longer cut. The bandsaw cannot turn 90°.
Stay to the waste side of the line, keeping approximately a blade width or extra kerf of excess material that will be sanded off later. The traced line is your target. If you cut this reference off at this stage, you won’t have anything to aim at when working at the sander.
Cutting freehand on the bandsaw and sanding to a line is a powerful and fundamental woodworking skill to learn. Here are a few tips to keep in mind when you work on the bandsaw:
- The blade is a straight line trying to follow a curve, think about a tangent line coming off the curve. You need to cut along the curve, not on the path of the curve itself.
- One huge advantage of the bandsaw is that you can slow down and even pause if a cut isn’t going as intended. Pause, take pressure off the blade, and slightly adjust if needed. You can even turn the power off, apply the brake, snake the blade from your cut, and cut from the opposite direction if needed.
- Don’t be in a hurry (see above). Be patient with yourself, the bandsaw is simple to operate, but skill always takes time to learn.
