Vertical Band Machining
Plan contour cuts around blade width and turning radius, and recognize the purpose of blade welding, band filing, and polishing attachments.
A vertical band follows a contour through the work
A vertical band follows a contour through the work
A vertical bandsaw supports the work on a table while a continuous band cuts through it. Moving the work along a marked path allows curved outlines as well as straight cuts. This can remove excess material before milling a profile.
Leave the planned finishing allowance on the retained side of the line, including room for the kerf. Use Shop Layout and Angle Measurement for marking the path and Choosing Shop Measuring Tools for checking the result. Tooth pitch and blade material are covered in Saw Blade Selection; speed and coolant in Cutoff Sawing.
The tightest curve sets the blade-width limit
The tightest curve sets the blade-width limit
A narrow blade can turn a tighter curve; a wide blade better resists wandering in a straight cut. Find the smallest radius on the intended saw path, then use the blade maker's width-versus-minimum-radius chart. Choose a width that fits both that path and the machine.
Radius is measured from the center of a curve to its edge; diameter is twice the radius. A chart's minimum radius is not a guarantee for every blade with that width: blade thickness and kerf clearance matter too. Do not force a wide blade around a tighter corner than its chart permits.
Why relief cuts help with some outlines
A relief cut runs in from a scrap edge toward the outline, allowing waste to separate in smaller pieces. Plan relief cuts on the waste side and preserve the finishing allowance. They can provide room to approach a contour from another direction; they do not make the blade itself capable of a smaller turning radius.
Blade welding closes the loop for some internal cuts
Blade welding closes the loop for some internal cuts
Blades may arrive as ready-welded loops. On equipment designed for it, a suitable open band can pass through a starting hole in the work and then be joined, making an internal contour accessible without a slot from the outside edge.
In general, blade joining involves preparing and aligning the ends, making a butt weld, heat-treating the joint as specified, finishing the weld flush, and inspecting it. The joint must flex around the wheels and pass through the guides. Follow the welder and blade maker's instructions for the exact sequence and settings; not every blade construction is suitable for a shop blade welder.
Why joining includes more than making a weld
Alignment keeps the band running straight. The prescribed annealing or tempering cycle restores suitable flexibility at the joint, and finishing removes raised weld material. A sound-looking joint alone is not proof that the loop is ready to run. DoALL's blade welder range is a starting point for equipment-specific documentation.
Filing and polishing require their own bands and guides
Filing and polishing require their own bands and guides
Some band machines accept a file band to remove small amounts of material and refine a contour, or an abrasive band to smooth a surface. These are dedicated attachments with matching guides and operating instructions, not ordinary saw blades used differently.
Confirm that the machine supports the attachment before selecting its band, speed, or lubricant. Hand finishing methods are in Bench Work with Hand Tools. For operating hazards and precautions, use Machine Hazards and Housekeeping, Personal Protective Equipment, and Metal Chips and Swarf.