Saturday, June 22, 2013

anticlockwise milling and clockwise milling

Processing method of Tungsten Carbide End Mills – anticlockwise milling (up milling) and clockwise milling (down milling)

Milling is one of the most common and most widely used processing methods, and for roughing milling of the various structural components and fine milling is almost by end milling. There are two ways, clockwise and anticlockwise milling, according to the cutting direction. The movement of the cutting edge and work piece is in the opposite direction or same direction, divided into the two kinds of conventional milling and climb milling.

Anticlockwise Milling:

Milling direction and feed in the opposite direction (milling against the feed) is anticlockwise milling; chip caused from the bottom into upper, so we also call it as up milling; Since the traditional processing and milling mostly used this way, so we also called it as conventional milling.

Processing method of Tungsten Carbide End Mills – anticlockwise milling (up milling) and clockwise milling (down milling)

Characteristics of anticlockwise milling:

  1. Chip shape is from thin to thick, and cutter afford force from light into heavy, which may prevent the cutter fracture by the impact.
  2. Suitable for milling casting black surface.
  3. Can be used in the old milling machine, no screw invalid gap movement.
  4. More friction, the blade is easy to blunt, short life.
  5. Easy shaken, the machined surface is rough, poor machining accuracy.
  6. The device is not easy to settle, which is not suitable for milling thin parts.
  7. More energy consumption.

Clockwise milling:

The milling and feed in the same direction (milling with the feeds) called clockwise milling; Due to cutting action is from no-machining face of work piece into down place (chips from thick into thin), so it is called down milling or climb milling.

Processing method of Tungsten Carbide End Mills – anticlockwise milling (up milling) and clockwise milling (down milling)

Characteristics of climb milling:

  1. Chip is from thick into thin, cutter affords force from heavy into light, easy to cause fracture by impact.
  2. Not suitable for milling castings, forgings, and the surface of the work piece with fish scale shape.
  3. The milling machine shall have a gap eliminator, or easy to produce screw invalid gap movement.
  4. Processing less friction, longer life of the cutter edge.
  5. Easy chucking, no vibration, and high accuracy of the machined surface.
  6. The device is easy to settle, it’s suitable for milling long thin work pieces.
  7. Less feed consumption.
In most of the milling case, in addition to the casting of the first milling and old milling Lo-gap chopping device need to use the anticlockwise milling, down milling is better than conventional milling.

Tuesday, June 18, 2013

Cutting Reference Data for End Mills of Various Materials

Cutting Reference Data for End Mills of Various Materials
Effective working solution depends on correct cutters, operation method, and technology.
Usual cutting conditions and major influence factors of CNC machines.
Introduction Formula
Cutting Data V(m/min) Cutting speed is decided by the diameter of end mills and its rpm V=Cutting speed(m/min)
D=diameter(mm)
N=rpm of one min of end mills(min-1)
Feed speed F(mm/min) Feed speed is the speed of relative one of work piece. Feed rate per flute is important for multi-flute end mills. F=Feed speed per minute
z= number of flute
f= Feed volume per flute
Cutting depth a(mm) Cutting depth is the thickness of flute machining on work piece. We always increase cutting depth to achieve its efficiency, but it is too deep to short tool life. It’s better to give proper cutting depth per flute, don’t increase feed rate and cutting depth together. -- --
Feed rate per flue
f(mm/刃)
Once a flute to cut -- --
Cutting width b(mm) Vibration caused by diameter of end mill, width of work piece, flute numbers, and cutting width. -- --
Cutting Speed
Work Material High Speed Steel Carbide – rough cutting Carbide – fine cutting
Cast iron (soft) 32 50-60 120-150
Cast iron (hard) 24 30-60 75-100
Malleable cast iron 24 30-75 50-100
Steel (soft) 27 30-75 150
Steel (hard) 15 25 30
Aluminum alloy 150 95-300 300-1200
Yellow Steel (soft) 60 240 180
Yellow Steel (hard) 50 150 300
Bronze 50 75-150 150-240
Copper 50 150-240 240-300
Hard Rubber 60 240 450
Fiber 40 140 200
Feed volume each side
Working Material Face cutter End Mill Spiral flute flat
end mill
Side Cutter Milling Cutter Metal gap cutter
HSS Carbide HSS Carbide HSS Carbide HSS Carbide HSS Carbide HSS Carbide
Cast Iron HB150-180 0.4 0.5 0.2 0.25 0.32 0.4 0.23 0.3 0.13 0.15 0.10 0.13
HB180-220 0.32 0.4 0.18 0.2 0.25 0.32 0.18 0.25 0.1 0.13 0.08 0.1
HB220-300 0.28 0.3 0.15 0.15 0.20 0.25 0.15 0.18 0.08 0.1 0.08 0.08
Malleable cast iron, Cast iron 0.3 0.35 0.15 0.18 0.25 0.28 0.18 0.2 0.1 0.13 0.08 0.1
Carbon steel Cutting steel 0.3 0.4 0.15 0.2 0.25 0.32 0.18 0.18 0.23 0.13 0.08 0.1
Soft steel, Steel 0.25 0.35 0.13 0.18 0.20 0.28 0.15 0.2 0.08 0.1 0.08 0.1
Alloy Steel Annealing robust steel HB180-220 0.20 0.35 0.10 0.18 0.18 0.28 0.13 020 0.08 0.1 0.05 0.1
HB220-300 0.15 0.3 0.08 0.15 0.13 0.25 0.10 0.18 0.05 0.10 0.05 0.08
HB300-400 0.10 0.25 0.05 0.13 0.08 0.2 0.08 0.15 0.05 0.08 0.03 0.08
Stainless steel 0.15 0.25 0.08 0.13 0.13 0.20 0.10 0.15 0.05 0.08 0.05 0.08
Al-Mg Alloy 0.55 0.5 0.28 0.25 0.45 040 0.32 0.30 0.18 0.15 0.13 0.13
Brass, Bronze speedy cutting 0.55 0.5 0.28 0.25 0.45 0.4 0.32 0.3 0.18 0.15 0.13 0.13
ordinary 0.35 0.30 0.18 0.15 0.28 0.25 0.20 0.18 0.10 0.10 0.10 0.18
hard 0.23 0.25 0.13 0.13 0.18 0.2 0.15 0.15 0.08 0.08 0.05 0.08
Coppper 0.30 030 0.15 0.15 0.25 0.23 0.18 0.18 0.10 0.10 0.08 0.08
Plastics 0.32 0.38 0.18 0.18 0.25 0.30 0.20 0.23 0.10 0.13 0.08 0.10