A spindle sander is basically a rotating cylindrical drum covered with a gritted paper sleeve. It is used to smooth saw marks on rounded cuts, smooth rough curved edges and sand the inside surfaces of deep hole cuts. A spindle sander is often used in finishing woodwork and home improvement projects that include rounded wood such as those found in facings, furniture legs and stair treads.
Sanding drums are traditional woodworking tools that have been used as attachments to a drill press. A drawback to this arrangement is that sanding takes place on the same spot on the drum all the time which can cause burn marks on the wood and uneven wear on the sanding sleeve. This problem can be solved by using an oscillating spindle sander.
An oscillating spindle sander moves the drum up and down at the same time that it rotates it. This reduces the static friction that causes burning and eliminates band marks. It also extends the life of the sanding sleeve by spreading the wear across a broader surface.
Spindle sanders can be stand-alone floor machines, bench-top models, or portable hand-held models. Floor models are high-end machines with equally high prices and are commonly found in larger industrial shops. Table-top models and portable models are more affordable and take up less space. This has allowed the spindle sander to become an addition to the home woodwork shop.
Bench-top models have a base that usually includes storage for spindles, sleeves, drum plates and table inserts. The sanding drum sits on top of a washer-like drum plate in the middle of a table that provides support for the wood being sanded. Sleeves fit down over the drum and table inserts slide down over the drum and sleeve to close the open space between the variable sized drums and the table.
The portable spindle sander is a hand-held sander that looks similar to a regular sander with the spindle projecting below it. The flat surface of the tool is held against the flat surface of the wood and the spindle is run along the curved outline to sand it. Oscillating portable sanders are also available.
A bench-top spindle sander can cost as little as $150 US Dollars (USD). A typical price for bench-top and portable models is between $250 and $400 USD. Floor shop models can cost over $3,000 USD.
Sanding drums come in various diameters with 3/4 inch (1.9 cm) and 1 1/2 inch (3.8 cm) being the most common. Sleeves are relatively inexpensive and come in several grit weights such as 50, 80 and 120. Smaller sized drums are used for smaller curves; larger drums for broader curves.
The home wood worker who does not have a dedicated spindle sander can convert an existing workshop tool, such as a router or drill press, to a type of spindle sander. On a router, the spindle is placed in the collet and tightened with the router table positioned just above the bottom of the spindle. On a drill press, the spindle is placed in the chuck and tightened with the table positioned just below the bottom of the spindle.