Re: CNC division

Ian,

Been there done that, several times. Draw the single tooth profile
of your wheel (actually the Y-Z plane on the mill).

Since you're using round edge cutters generate Gcode as if this was a
normal X-Y plane drawing being cut using a small diameter end mill
equivalent to your cutter's radius. Use an editor to change the
generated X's & Y's to Y's & Z's respectively. Of course, for
complicated shapes this method assumes your mill will circular
interpolate in the Y-Z plane. I've done the actual cutting with no X
motion and no rotary motion. Although, sometimes you may have back
the cutter out of the tooth profile to do a rotary move to get a new
approach angle for your cutter to create your desired profiles.

Note that in creating the tool's path you have to be clever, in that
you're really cutting on the perimeter of the cutter, but the Gcode
will assume centerline of your cutter axis. So after drawing your
cutter path, offset it horizontally equal to your cutter's radius.
In other words, your motion commands will be reflecting the
centerline of your spindle, while your cutting will be happening at a
point equal to the cutter's radius away.

Once you've finished one tooth, rotate and repeat.

Confusing enough?

This method works equally well with manually indexed work heads.

Doug

--- In CAD_CAM_EDM_DRO@y..., "Ian Wright" <Ian@i...> wrote:
>(snip)
>
. So, I reckon that,
> with a bit of clever maths, it should be possible to persuade a
little cnc
> mill to generate the form by coordinated movements of the A, Z and
Y axes
> while running the thin, round edged slitting saw cutter back and
forth with
> the X axis. I haven't yet found any software which would seem able
to
> produce the g-code for this from a dxf file (unless you can suggest
one) and
> so am almost resolved to coding it manually, in which case, having
a method
> of producing a 'loop' to do the tooth shape and a separate 'loop'
to index
> from one tooth to the next would seen to be easier than coding the
whole lot
> as one long file.
>