Drilling with high rpm compared to drilling with conventional speed

IACDS Bauma 2013 seminar 2013-04-19
High rpm drilling today
Why is 40 - 50 m/sec peripheral speed normal for a wall saw but not for a core drill?
4.5 m/ second peripheral speed is
often standard in Sweden,
whereas some would consider this
high speed drilling.
Different manufacturers have
different recommendations.
Bohrmotor Pentruder MDU mit Untersetzungsspindel SH
Umfangsgeschwindigkeit m/s
Stufe 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Drehzahl 320 400 480 560 640 720 800 880 960 1040 1120 1200 1280 1360 1440
Ø 52 0,87 1,09 1,31 1,52 1,74 1,96 2,18 2,39 2,61 2,83 3,05 3,27 3,48 3,70 3,92
Ø 62 1,04 1,30 1,56 1,82 2,08 2,34 2,60 2,86 3,11 3,37 3,63 3,89 4,15 4,41 4,67
Ø 72 1,21 1,51 1,81 2,11 2,41 2,71 3,01 3,32 3,62 3,92 4,22 4,52 4,82 5,12 5,43
Ø 82 1,37 1,72 2,06 2,40 2,75 3,09 3,43 3,78 4,12 4,46 4,81 5,15 5,49 5,84 6,18
Ø 92 1,54 1,93 2,31 2,70 3,08 3,47 3,85 4,24 4,62 5,01 5,39 5,78 6,16 6,55 6,93
Ø 102 1,71 2,14 2,56 2,99 3,42 3,84 4,27 4,70 5,12 5,55 5,98 6,41 6,83 7,26 7,69
Ø 107 1,79 2,24 2,69 3,14 3,58 4,03 4,48 4,93 5,38 5,82 6,27 6,72 7,17 7,62 8,06
Ø 112 1,88 2,34 2,81 3,28 3,75 4,22 4,69 5,16 5,63 6,10 6,56 7,03 7,50 7,97 8,44
Ø 122 2,04 2,55 3,06 3,58 4,09 4,60 5,11 5,62 6,13 6,64 7,15 7,66 8,17 8,68 9,19
Ø 132 2,21 2,76 3,32 3,87 4,42 4,97 5,53 6,08 6,63 7,18 7,74 8,29 8,84 9,39 9,95
Ø 142 2,38 2,97 3,57 4,16 4,76 5,35 5,95 6,54 7,13 7,73 8,32 8,92 9,51 10,11 10,70
Ø 152 2,55 3,18 3,82 4,45 5,09 5,73 6,36 7,00 7,64 8,27 8,91 9,55 10,18 10,82 11,45
Ø 162 2,71 3,39 4,07 4,75 5,43 6,10 6,78 7,46 8,14 8,82 9,50 10,17 10,85 11,53 12,21
Ø 172 2,88 3,60 4,32 5,04 5,76 6,48 7,20 7,92 8,64 9,36 10,08 10,80 11,52 12,24 12,96
Ø 182 3,05 3,81 4,57 5,33 6,10 6,86 7,62 8,38 9,14 9,91 10,67 11,43 12,19 12,95 13,72
Ø 192 3,22 4,02 4,82 5,63 6,43 7,23 8,04 8,84 9,65 10,45 11,25 12,06 12,86 13,67 14,47
Ø 200 3,35 4,19 5,02 5,86 6,70 7,54 8,37 9,21 10,05 10,89 11,72 12,56 13,40 14,23 15,07
Ø 225 3,77 4,71 5,65 6,59 7,54 8,48 9,42 10,36 11,30 12,25 13,19 14,13 15,07 16,01 16,96
Ø 250 4,19 5,23 6,28 7,33 8,37 9,42 10,47 11,51 12,56 13,61 14,65 15,70 16,75 17,79 18,84
Ø 300 5,02 6,28 7,54 8,79 10,05 11,30 12,56 13,82 15,07 16,33 17,58 18,84 20,10 21,35 22,61
Ø 350 5,86 7,33 8,79 10,26 11,72 13,19 14,65 16,12 17,58 19,05 20,51 21,98 23,45 24,91 26,38
Ø 400 6,70 8,37 10,05 11,72 13,40 15,07 16,75 18,42 20,10 21,77 23,45 25,12 26,79 28,47 30,14
Ø 450 7,54 9,42 11,30 13,19 15,07 16,96 18,84 20,72 22,61 24,49 26,38 28,26 30,14 32,03 33,91
Ø 500 8,37 10,47 12,56 14,65 16,75 18,84 20,93 23,03 25,12 27,21 29,31 31,40 33,49 35,59 37,68
Ø 550 9,21 11,51 13,82 16,12 18,42 20,72 23,03 25,33 27,63 29,93 32,24 34,54 36,84 39,15 41,45
Ø 600 10,05 12,56 15,07 17,58 20,10 22,61 25,12 27,63 30,14 32,66 35,17 37,68 40,19 42,70 45,22
Ø 650 10,89 13,61 16,33 19,05 21,77 24,49 27,21 29,93 32,66 35,38 38,10 40,82 43,54 46,26 48,98
Ø 700 11,72 14,65 17,58 20,51 23,45 26,38 29,31 32,24 35,17 38,10 41,03 43,96 46,89 49,82 52,75
Ø 750 12,56 15,70 18,84 21,98 25,12 28,26 31,40 34,54 37,68 40,82 43,96 47,10 50,24 53,38 56,52
Standard-Bohrkronen mit optimaler Umfangsgeschwindigkeit 2-4 m/s
High-Speed Bohrkronen mit erhöhter Umfangsgeschwindigkeit 4-6 m/s
• More difficult to cool drill bit.
• More difficult to remove slurry.
• Lower price Lower quality of Core
drill, Drill rig and Core bit
• Price pressure Difficult for tool
manufacturers to produce the optimal
drill bit.
Bauma 2013
Munich seminar
Bauma 2013
Munich seminar
Our thesis – Higher speeds Faster drilling
High speed drilling – Important criteria for success
Power = Constant
Peripheral speed x 2 Concrete removal rate x 2
rpm
Powerful core drill
Adjustment of rpm
Rigidity of drill
system
Drill bit
Sufficient cooling
Concrete
removal
rate
Skilled operator
Bauma 2013
Munich seminar
Bauma 2013
Munich seminar
2