Taig Micro Mill Tachometer & SFM
Taig Micro Mill
Taig Micro Mill DRO &
X Y
Z Axes Scales.
Taig CNC Mill DRO
RF-25 Mill
RF-25 Mill DRO
X Y Z Axes
Scales. RF-25 Mill Tachometer & SFM
9x20 Lathe,
9x20 Lathe DRO X
& Z1 Axis Scale.
9x20 Lathe
Tachometer & SFM Taig
Micro Lathe DRO
The
Fairchild QRB1114 E-O sensor
is mounted onto a milled
Delrin plastic enclosure so the circuit will not short.
Mounted to the mill head using the two, pre-existing 10-32 tapped holes.
Alignment is easily accomplished by moving the spindle up or down on the
dovetail mount.
The shielded power/signal cable exits to the left through a heavily chamfered hole in the aluminum motor support.
I know what the fixed speeds are, though it's easier to look at the
DRO RPM than
the chart, but it's the SFM calculator that I find useful.
Did not need the black tape. The circuit easily picks up a
pulse from the black set screw,
representing about a 3.5% duty cycle. The sensor is 0.286" from the pulley
surface.
Sensor circuit enclosure with the cover removed. The
two, flat-head screws are 3-48.
A nylon tie serves as cable strain relief & the hot glue keeps it from rotating.
A near-infrared (NIR) camera picture, using the
Sony DSC-F717 night shot
mode, showing
the Fairchild NIR emitter glowing at 940 nm.
SFM is only a starting point. When
cutting metal, one attends to (among other things): speed, feed,
chip size, chip length, chip coloration, coolant, rigidity, surface finish,
sounds, smell & vibration.
There are numerous, interacting variables that are unique to any given
machine & setup that simply can not be accounted for by SFM tables.
The rigidity, coolant, and feed in a vertical machining center is a bit better
than a hand drill.
So to say that
one SFM value should be the
same for both is a stretch.
Mill Surface Feet per Minute (SFM)
SFM = (RPM· π· DIAMETER)/12 where: π = 3.14159 & the diameter is in inches
Operation is similar to the Lathe Tachometer & SFM
For the ShumaTech DRO-350M.
AUX ON in DRO setup (Function 0)Select "no tool offset" (Function 6, 0)
Zero DRO scales
Define tool offsets (Function 5, #1~9, diameter of end mill (or other) , Z offset)
Select mounted tool offset (Function 6, #1~9)
Function 7 toggles display between RPM & Z-Axis DRO
Function 8 toggles display between SPM & Z-Axis DRONotes: Scales directions & polarities must be correctly defined in the DRO setup.
SFM changes as the cutter diameter changes.
Larger diameters have higher SFM than smaller diameters for a given RPM.
Double check initial DRO calculated SFM values by using hand calculations.
SFM is applied equally for either mill or lathe operations.
Taig Micro Mill DRO & X Y Z Axes Scales