Machining Operation; Starting Spindle Rotation; Recommended Spindle Speeds - Promac PBM-1839V Operating Instructions Manual

10.0 Machining Operation

CAUTION:
Never place your fingers in a position where they could
contact any rotating tool, chuck or cutting chips.
Remove cutting chips with the aid of an appropriate chip hook
when the machine is at a standstill only.
Never stop the rotating chuck or tool with your hands.
Always close the chuck guard before you start the machine.
Secure work piece to the table with clamps or a vice to prevent
rotating with the drill bit.
When using a vice, always fasten it to the table.
Check the save clamping of the work piece, chuck and tools
before starting the machine.
Never do any works "freehand" (hand-holding the work piece
rather than supporting it on the table).
Support long work pieces with helping roller stands.
Always adjust the depth stop to prevent drilling into the table
or into the work holding device.
Feed a drill bit into the material with only enough force to
allow the drill bit to work.
Feeding too slowly may cause burning of the work piece or
tool. Feeding too quickly may cause the motor to stop and/or
the drill bit to break.
Do not use wire wheels or grinding wheels on this machine.
Never cut magnesium - high danger to fire!
Measurements and adjustments may be carried out when the
machine is at a standstill only.
In case of danger push the emergency stop button.

10.1 Starting spindle rotation

Before starting the machine check the proper workpiece
clamping and cutting tool setup.
Close the chuck guard before you start the machine.
Make sure the Rev / Power-OFF/ Fwd switch (O, Figure 9-1) is
in OFF position before you connect the machine to the power
supply.
Digital spindle speed display (R, Figure 9-1) is illuminated when
connected.
Use the Rev / Power-OFF/ Fwd switch (O, Figure 9-1) to select
the spindle rotating direction and to energize the electrics.
Start the machine with the Speed control knob (N, Figure 9-1).
Stop the machine by turning the knob counter-clockwise until
it clicks into OFF position.
The emergency stop button (Q, Figure 9-1) stops all machine
functions.
Turn emergency stop button clockwise to reset.
Unplug the machine if not in use.

10.2 Recommended spindle speeds

CAUTION:
Generally speaking, the smaller the tool diameter, the greater the
RPM required. Soft materials require higher speeds; hard metals
slower speeds.
Metal is usually machined at slower speeds and cutting oil is
applied.
These are recommended speeds for a 10mm high speed steel
(HSS) tool (e.g. drill bit).
Plastic .................................................................... 2000 /min
Aluminium ............................................................. 2000 /min
Brass ...................................................................... 1000 /min
Cast iron ................................................................ 1000 /min
Mild steel ................................................................ 800 /min
High carbon steel .................................................... 600 /min
Stainless steel ......................................................... 300 /min
For carbide tools (HM), 5 times higher speeds can be chosen.
For example:
Milling mild steel with an end mill of 20mm allows a speed of:
With HSS tool .......................................................... 400 /min
With carbide tool .................................................. 2000 /min
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