1) to choose right cutting machine
Pay attention on machine’s motor power, rotation per minute, stiffness and accuracy etc while choosing the machine.
Diameter smaller than 180mm, it is suggested to have machine with motor power 1-1.5kw, 9300-13000r.p.m adjustable speed;
Diameter from dia.180 to 230mm, it is suggested to having machine with motor power 1.5-2.5kw, 6600-8500r.p.m adjustable speed;
The stone blade from dia.250mm to 600mm blade is suitable to take machine with motor power more than 6kw (include power tools machine),linear speed 20-60/s adjustable; the construction blade required minimum 11kw (power tools machine) or min. 20kw (petrol or diesel machine), linear speed 35-70m/s adjustable;
The motor power of the machine is decided by the blade diameter and numbers, for example dia.1600 single blade machine require motor power 35-50kw with 270-360r.p.m.
2)to fix the blade correctly
Fixing the blade correctly and accurately affects the blade cutting efficiency, cutting quality and life intently.
After blade fixing, it is required to have blade working stably, no vibration (except the factor of blade core quality and machine rigidity).
While fixing the blade, the blade diamond open is same direction with the rotating direction of main shaft; to make sure the contact surface of blade arbor hole, machine shaft, flange are clean with flatness. The diameter of flange is decided by the blade diameter. If the flange are too small against to the blade diameter, the end face of the blade ‘s oscillation is big; if the flange diameter is big against the blade diameter, it will increase the jumping of blade and less the blade’s effective cutting depth.
After fixing the blade, the value of jumping edge face of blade should meet the required value before start cutting.
3) to choose the right cutting parameter for the blade
a) blade’s linear speed
with low or high linear speed, the saw blade will have irregular consumption of the segment as well as lower the blade’s efficiency. Too low speed, the segment has longer time contact with the cutting objective, then the friction factor and heat will increase that damage the blade; Too high speed, the single diamond ‘s cutting depth in single unit of time is less, then the burden of cutting movement made by segment between the objective is big. it is not only made the big consumption of diamond against the machine as well as the diamond’s crash and dropping.
The harder the cutting objective, the lower the linear speed of the blade.
The stronger abrasiveness or the softer cutting objectives, the liner speed should be bigger. In general speaking, medium and big diameter of circular saw blade, it use 25～30m/s linear speed fo the granite with high content of quartz or for multi blade cutting;
Lower quartze of granite having linear speed of 30~40m/s; for marble , it will be 40~50m/s; for limestone, it will be 45~60m/s; for sandstone, it will be 40~65m/s;
Table 3 is the suggested RPM For different hardness of stone;
Table 4 is the exchange relation between the blade diameter and RPM as well as the linear speed.
b) Cutting output and blade cutting depth and speed
The cutting output is also called as cutting efficiency. It is the blade cutting depth multiple feeding speed; that is, the area cut in single time unit, normally show as cm2/min or m2/h.
The cutting depth affects the diamond saw blade’s life span, cutting efficiency, stress status and cutting quality. In General speaking, when the linear speed and requirement of cutting surface is,it is suggested to having small cutting depth and lower feeding speed. On the contrary, to use more cutting depth. Within allowance of the machine capacity, it should maximize the cutting depth for increase the cutting efficiency.
Feeding speed affects the cutting output, blade load stress and the area for heat radiation during cutting etc. too much speed, the consumption of the segment will fast, the diamond drop early; too less speed, the consumption of the segment is slow, the diamond cannot open or get polished easily, make the cutting resistance more, taking more power and slow the cutting output. In general, to cut soft material like marble, it should using big cutting depth and slow feeding speed, it will help the cutting efficiency; to cut the fine grain granite, it should increase feeding speed to avoid the diamond get ground loosing sharpness; for the big grain granite with soft and hard constituent, it should using less cutting speed otherwise the blade vibrate and make diamond crush and then slow the cutting efficiency. To cut granite, it has linear speed of 9~12m/min normally. In machine operation, the feeding, return and out of the blade should be slow;
Speed for cutting should be same. Through practice, for same cutting objective, to increase cutting depth and feeding speed, although this can increase the cutting output but he blade consumption is fast and then life span getting less; meantime, the power increase during cutting that cost big.
| Table 3.blade diameter& stone hardness& suggested R.P.M relations |
|||||
| Diameter mm | Marble r.p.m | Soft granite r.p.m | Hard granite r.p.m | Cooling wanter liter/min | power kw |
| 200 | 4000-4500 | 3100-3800 | 2400-2900 | 5-10 | 1.5-4 |
| 250 | 3200-3800 | 2500-3050 | 2000-2300 | ||
| 300 | 2600-3200 | 2050-2550 | 1600-1900 | 10-15 | 5-7.5 |
| 350 | 2200-2800 | 1750-2200 | 1400-1650 | ||
| 400 | 2000-2400 | 1530-1950 | 1200-1450 | 7.5-11 | |
| 450 | 1800-2200 | 1370-1700 | 1100-1300 | 15-20 | |
| 500 | 1600-1900 | 1230-1530 | 1000-1150 | 11-15 | |
Table 4.blade diameter &linear speed & R.P.M relations
| Linear speed m/s |
20 | 25 | 30 | 35 | 40 | 45 | 50 | 55 | 60 | 65 | 70 | 75 | 80 |
| Diameter mm | r.p.m | ||||||||||||
| 105 | 3821 | 4777 | 5732 | 6687 | 7643 | 8598 | 9554 | 10509 | 11464 | 12240 | 13375 | 14331 | 15286 |
| 125 | 2939 | 3674 | 4409 | 5144 | 5879 | 6614 | 7349 | 8083 | 8819 | 9554 | 10289 | 11024 | 11758 |
| 150 | 2547 | 3184 | 4316 | 4458 | 5095 | 5732 | 6369 | 7006 | 7643 | 8280 | 8916 | 9554 | 10190 |
| 200 | 1910 | 2388 | 2866 | 3343 | 3821 | 4299 | 4777 | 5254 | 5732 | 6210 | 6687 | 7165 | 7643 |
| 250 | 1528 | 1910 | 2292 | 2675 | 3057 | 3439 | 3821 | 4203 | 4585 | 4968 | 5350 | 5732 | 6114 |
| 300 | 1273 | 1592 | 1910 | 2229 | 2547 | 2866 | 3184 | 3503 | 3821 | 4140 | 4458 | 4777 | 5095 |
| 350 | 1091 | 1364 | 1637 | 1910 | 2183 | 2456 | 2729 | 3002 | 3275 | 3548 | 3821 | 4094 | 4367 |
| 400 | 955 | 1194 | 1433 | 1671 | 1910 | 2149 | 2388 | 2627 | 2866 | 3105 | 3348 | 3582 | 3821 |
| 450 | 849 | 1061 | 1273 | 1486 | 1698 | 1910 | 2123 | 2336 | 2547 | 2760 | 2972 | 3184 | 3397 |
| 500 | 764 | 955 | 1146 | 1337 | 1528 | 1719 | 1910 | 2101 | 2292 | 2484 | 2675 | 2866 | 3057 |
| 550 | 694 | 868 | 1042 | 1215 | 1389 | 1563 | 1737 | 1910 | 2084 | 2258 | 2431 | 2605 | 2779 |
| Linear speed（m/s）reference：soft marble 50、hard marble 40、soft granite 30、hard granite 25、soft sandstone 60、hard sandstone 50 | |||||||||||||
Table 5.the recommendation for the granite blade cutting efficiency.
| Hardness class | Cutting depth mm | Cutting sped m/min | Linear speed m/s | Efficiency cm2/min |
| 1 | 10～15 | 2.5～3.5 | 24～32 | 250～525 |
| 2 | 8～12 | 200～420 | ||
| 3 | 6～10 | 150～350 | ||
| 4 | 5～8 | 125～280 | ||
| 5 | 4～6 | 100～210 |
