The ideal installation for any machine tool is an endless Betalon-Multiply belt; these are light in weight but immensely strong and stretch resistant. They absorb shock loads well, have a high coefficient of friction, enjoy a proven record of reliable industrial service and can be made in almost any combination of length and width. The belt joint is machine scarfed, prepared and heat vulcanised - and results in a tremendously strong unit. Of course, as with an ordinary V belt, you may have to dismantle pulleys, etc., to fit it, but the trouble taken will be well worth while - the drive to your machine will be quieter, smoother and much more reliable. This belting can also be supplied as a DIY kit with the ends ready scarfed and provided with the glue and instructions. When you order a DIY kit you, must, of course, measure the length you need very carefully* - all we need is the required finished length. Don't worry about the overlap, we take care of that. If in doubt about any aspect of this just phone 01298-871633 (09:00 to 23:00) for advice....
*Most - but not all - belt-drives have a tensioning mechanism. As belts will stretch slightly in service, before measuring set any adjustment so that the pulleys are nearly, but not quite, as close together as possible.
Tensioning systems include:
1) one or more jockey pulleys that press on the back of the belt
2) the motor mounted on an adjustable plate
3) to set the final tension possibly an "over-centre" lever with a screwed-rod and turn-buckle
4) grinding machines sometimes have a weighted jockey pulley. To get the correct length remove the weight and pull the measuring tape (or old belt) straight between the pulleys.
Measure using a non-stretch (e.g. dress-maker's) tape. If two people measure independently mistakes are less likely.
Width:In general you can use a belt to the full width of the pulley less 2 mm - though if the pulley has flanges reduce the belt width by 4 mm to allow a small gap at each side.