81 - Ultimate Sharpening Station, страница 10

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Swivel with Locking Brake

The right casters can add versatility to any shop.

When I design a project that includes casters, I put a lot of thought into what kind of caster to use. There's more to casters than just finding the lowest price at the neighborhood hardware store.

Types of Casters. Casters come in two basic types: fixed and swivel. The fixed caster (sometimes called "rigid") is really quite simple. If you look at the left photo, you can see that it's essentially a wheel on an axle, which is riveted to a pair of "horns," or side brackets. The brackets are attached to a mounting plate so you can fasten the caster to your project. There's not much to the wheel either. It simply rolls forward and backward, just like the rear wheels of your car do.

The other type is called a swivel caster, which is a big upgrade over the fixed. It has the same basic setup, except that a ring of ball bearings is sandwiched between the wheel assembly and the mounting plate (see photo at right). Those bearings allow it to rotate 360°, improving maneuverability quite a bit.

Locking Swivel. With swivel casters, you can move your projects and tool stands around the shop with ease. But what do you do to

prevent them from rolling once they're where you want them? If you look at the lower photos again, you'll see a butterfly-shaped lever on the side of the wheel.

The lever is actually a cam-style compression brake. Pressing the "ON" side down causes the housing to squeeze against the wheel, preventing the wheel from rolling. Stepping on the opposite end of the wing releases the wheel. In the "locked" position, the caster can still swivel, but it can't roll. So, while this caster is "officially" a locking swivel, that's a bit of a stretch.

These two types of casters have been the shop standard for years. Then, a better design came along.

Double-Locking Swivel. A caster with a double-lock not only prevents

the wheel from rolling, but also stops it from swiveling. The way this caster works is pretty interesting. The first tiling you'll notice is that the brake lever has been moved behind and on top of the wheel (photo above). Now, if you peek underneath the lever (photo on opposite page) while pressing down on it, you'll see the brake shoe come in contact with the wheel to stop it from rolling.

If you look at the front of the wheel while pressing the lever, you'll see the swivel brake shoe slide in and mesh with the bearing retainer ring that has "teeth" cut into it. This is the mechanism that prevents the caster from rotating.

Locking Caster. ►

The cam-style compression brake stops the wheel from rolling, but still allows the caster to swivel.

k Fixed Caster.

Fixed casters only roll forward and backward, but provide good stability.

10 ShopNotes No. 81