General Guide Lines
There are several general guidelines which are applicable to all timing belts, including miniature and double-sided belts:
Drives should be made with ample reserve hp capacity. Usage of overload program factors is important. Belts ought to be rated of them costing only 1/15th of their particular ultimate strength.
For MXL pitch belts, the smallest recommended pulley will have 10 teeth. For additional pitches, Table 8, ought to be used.
The pulley diameter should never be smaller than the width of the belt.
Belts with Fibrex-glass fiber pressure members shouldn’t be subjected to sharp bends or rough handling, since this could cause breakage of the fibers.
To be able to deliver the rated hp, a belt must have six or more tooth in mesh with the grooves of the smaller pulley. The number of tooth in mesh may be obtained by formula given in SECTION 24 TIMING BELT DRIVE SELECTION PROCEDURE. The shear strength of a single tooth is only a fraction of the belt break power.
Due to a slight aspect thrust of synchronous belts in movement, at least a single pulley in the get must be flanged. When the center distance between the shafts is 8 or more times the size of small pulley, or when the get is operating on vertical shafts, both pulleys should be flanged.
Belt surface speed shouldn’t exceed 5500 feet per minute (28 m/s) for larger pitch belts and 10000 feet per minute (50 m/s) for minipitch belts. For the HTD belts, a speed of 6500 feet each and every minute (33 m/s) is certainly permitted, whereas for GT2 belts, the maximum permitted rate is 7500 foot per minute (38 m/s). The utmost allowable operating velocity for T series is certainly 4000 feet per minute (20 m/s).
Belts are, generally, rated to yield a minimum of 3000 hours of useful life if all instructions are properly followed.
Belt drives are inherently efficient. It can be assumed that the efficiency of a synchronous belt drive can be greater than 95%.
Belt drives are usually a way to obtain noise. The rate of recurrence of the sound level increases proportionally with the belt rate. The higher the original belt pressure, the higher the noise level. The belt teeth entering the pulleys at high acceleration become a compressor and this creates noise. Some noise may be the consequence of a belt rubbing against the flange, which may be the result of the shafts not being parallel. As demonstrated in Figure 9, the noise level is substantially reduced if the PowerGrip GT2 belt has been used.
If the drive is part of a sensitive acoustical or electronics sensing or recording device, it is recommended that the back surfaces of the belt be ground to assure absolutely uniform belt thickness.
For a few applications, no backlash between the driving and the driven shaft is permitted. For these situations, special profile pulleys could be produced without any clearance between the belt tooth and pulley. This might shorten the belt existence, but it eliminates backlash. 
Number 10 displays the superiority of PowerGrip GT2 profile as far as reduction of backlash is concerned.
Synchronous belts are often powered by stepping motors. These drives are put through continuous and large accelerations and decelerations. If the belt reinforcing dietary fiber, i.e., stress member, along with the belt materials, possess high tensile power and no elongation, the belt will not be instrumental in absorbing the shock loads. This will result in sheared belt tooth. Therefore, take this into consideration when how big is the tiniest pulley and the components for the belt and stress member are selected.
The choice of the pulley material (metal vs. plastic material) is normally a matter of price, desired precision, inertia, color, magnetic properties and, above all, personal preference predicated on experiences. Plastic material pulleys with metallic inserts or steel hubs represent a good compromise.
PRECAUTIONS
The following precautions should be taken when installing all timing belt drives:
Timing belt set up ought to be a snug in shape, neither too limited nor too loose. The positive hold of the belt eliminates the need for high initial tension. As a result, a belt, when set up with a snug match (that is, not too taut) assures much longer life, much less bearing put on and quieter procedure. Preloading (often the cause of premature failure) isn’t required. When torque is definitely unusually high, a loose belt may “leap tooth” on starting. When this happens, the tension ought to be increased steadily, until satisfactory procedure is attained. An excellent rule of thumb for installation tension is as demonstrated in Figure 20, and the corresponding tensioning force is shown in Table 9, both demonstrated in SECTION 10 BELT TENSIONING. For widths other than shown, increase push proportionally to the belt width. Instrumentation for measuring belt pressure is obtainable. Consult the merchandise portion of this catalog.
Be sure that shafts are parallel and pulleys are in alignment. On an extended center get, it is sometimes recommended to offset the driven pulley to compensate for the tendency of the belt to run against one flange.
On a long center get, it is imperative that the belt sag is not large enough to permit tooth on the slack part to engage the teeth on the tight side.
It is necessary that the frame supporting the pulleys be rigid at all times. A nonrigid frame causes variation in center length and resulting belt slackness. This, subsequently, can result in jumping of tooth – specifically under beginning load with shaft misalignment.
Although belt tension requires small attention after preliminary installation, provision should be designed for some middle distance adjustment for ease in installing and removing belts. Usually do not drive belt over flange of pulley.
Idlers, either of the within or outdoors type, are not recommended and really should not be used except for 
power takeoff or functional make use of. When an idler is essential, it should be on the slack aspect of the belt. Inside idlers should be grooved, unless their diameters are greater than an equivalent 40-groove pulley. Flat idlers should not be crowned (use advantage flanges). Idler diameters must go beyond the smallest diameter get pulley. Idler arc of contact should be held to the very least.
As well as the general suggestions enumerated previously, particular operating features of the drive must be considered.