Belt sanders are the proper tools for giving shape of a piece of furniture of metal or to remove a part of it quickly. You can control how much is removed by using different rotation and different coarse belts. They are used in an intermediate phase of the finishing process. Although we can find portable and hand held belt sanders we must keep in mind that the sand paper can damage the human skin and flesh very rapidly if they are not operated with caution. Wearing safety goggles it's a must.
 
Modern belt sanders comes with dust collector and with adjustable motor speeds. Nevertheless wearing a dust mask is recommended for people with respiratory problems. When choosing one we have to consider the common sizes of the belts found in DIY stores nearby 3 inches by 18 inches, 3 inches by 21 inches and 4 inches by 24 inches, sufficient for most  jobs. Non standard sizes can be expensive and hard to find.

There are also stationary belt sanders suited for professional use with larger belt sizes.
The sander should be used in parallel with the wood grain. It can be used in different angles to have a different pressure of sanding. When used on a flat surface at higher rotation it tends to built up heat in the sanding belt. Belt sanders can come in handy for restoring old furniture with pealed varnish, or with little defects. Using one you could gain hours if not days of time consumed before with hand sanding a piece of furniture or metal.
They tend to become the second nature for a person who has a lot of sanding to do around the house for rounding edges of metal or wood, cleaning old paint or for creating new and wonderful objects.

These power tools tend to be noisy. If the noise makes you uncomfortable you could buy some protective ear muffs. They weigh around 11 lbs. The heavier ones are good for sanding without fatigue because you don't have to apply downward pressure on it to get results. You only have to guide the machine. Starting a belt sander can be a tricky task. Some of them immediately after starting tend to go to the highest rotation mode, others have soft start and go gradually to the higher rotation mode. The design of the handle is a factor to look for when buying one. There are belt sanders with handles made of combination of rubber and plastic or metal. Ease of belt changing is important in a belt sander. Some of them have a tension lever for this. Remember that for using properly this kind of tools it takes lots of practice.