The amount of time between sharpenings is difficult to project since it depends on several factors, such as, how much hair are your cutting, what type of hair, how clean is the hair, is it wet or dry, and the amount and level of maintainance you apply to your blades.

To maximize the life of your blades make sure you keep them clean, well oiled, and protected from moisture.

Also make sure the hair you are clipping is as clean and dry as possible.

My blades have developed a serious 'rattle' when running on my clipper. Do I have problem with my clipper?

If it is your clipper it is not serious and is easily fixed. Two items will cause a blade to 'rattle' when running on a clipper.

The hinge on the clipper could be worn and in need of replacement, but I doubt if this is the problem.

More than likely it is the socket on blade that needs to be adjusted. It is common for the ears of the socket to spread apart during use.

If you are using a sharpening service they may be doing a poor job of maintaining your blades. The socket should be checked and adjusted every time the blade is sharpened.

It is very easy to do this adjustment. I use a length of 5/8 key stock (attainable at any hardware store) and a pair of common pliers.

Place the key stock between the two ears of the socket and bend them to fit.

Your problem should be solved..