Reference Section > Touchcut G Code Reference > Notes on Using G-Codes:

Touchcut can use special macros to enable certain chamfer milling tools to be used to machine a chamfer on the top and optionally the bottom of a hole. For a traditional "V-style' chamfer tool, the chamfer macro is not necessary, just use a drill feed to depth command , ie M30Dd.

T1(Chamfer Bit)
M38D20.E2C0.5

Where:

T1(Chamfer Bit) - is selecting the bit named "Chamfer Bit". (This bit will only be available for chamfering)

M38 - specifies perform chamfer here

D20. - specifies the nominal hole diameter is 20 mm

E2 - specifies edges to chamfer (where 1 = Top, 2 = Bottom, 3 = Top & Bottom)

C0.5 - specified chamfer width

In Touchcut you will need to have the tool set up as a chamfering tool:
eg Parameters for Kennametal KIPR046SD2645:
Tip Diameter 0.46" (11.684 mm)
Tip Height 0.196" (4.9784 mm)
Head Diameter 0.897" (22.7838 mm)
Shaft Diameter 0.5" (12.7 mm)

Notes:

The Cut Speed is the speed at the head diameter

The Foot Down option runs the chamfer routine with the foot down. The foot "floats" on the plate- this can provides the best height following, bit can lead to some scratching of the top of the plate.

The Type of bit is Chamfer (can only be used with the chamfer routine)

The Length is to the bottom of the bit

The Shaft Diameter is the diameter bit holding the tip

The Head Diameter is the outermost diameter of the tip (as it revolves)

The Tip Diameter is the diameter at the base of the tip (as it revolves)

The Tip Height is the height from the bottom of the tip to the edge of the tip

This can be adjusted allow for repeatable chamfer errors on the top chamfer

The Mat Thk. Adj. value can be adjusted to allow for variation in the plate thickness. It will adjust the bottom chamfer.

It has been assumed that the chamfer angles are at 45°

If doing a bottom chamfer, it is assumed the hole has been drilled deep enough for the bit to plunge

If doing a bottom chamfer, the selected material thickness is used for plate thickness

Trapped Error conditions:

If the hole is smaller than the shaft diameter

If the chamfer width is greater than the difference between the Head and Shaft radii

If doing a bottom chamfer, if the hole is smaller that the head diameter

Movement Notes:

The chamfer routine will adjust the height and path offset to ensure that the center of the cutting edge is utilized.

The bit will rapid down to the correct height with the head radius 2 mm away from the edge of the hole

The bit will then lead in to the path horizontally

Once complete the bit will either retract immediately (top chamfer only) or rapid to the center of the hole before retracting

Snap Chamfering

Snap Chamfer tools are supported as well. These are tools with a spring loaded blade designed to be pushed in and out of a hole while spinning; the blade creates a small chamfer as it enters the hole and its spring is compressed. These tools are used in production environments where a large number of the same size hole needs chamfering, as a different snap-chamfer tool is needed for each hole size.

An example of a "Heule" brand snap chamfer is shown below:

These bits use the M38 chamfer macro, however they only require the Edge parameter (E1=Top, E2=Bottom, E3=Both). The Hole Diameter D parameter is optional and is only used to display the hole diameter on the graphics. The chamfer C value will be ignored if present.