Re: 5-axis Taig Mill

Hi Rab,

I haven't thought it completely through, but as I've figured out so far:

1 Calculate angle of cutter before each linear move.

2 Calculate angle as third component (axis) per each cord step on
circular interpolations (much the same as a third helical/linear axis
is). That is, the cutter would be constantly turning, as each new point
on the arc is calculated. (using a "rotated arc" calculation).

3 Previous position and target positions give direction of any cut.

4 No complex contouring can be done at this level of implementation.

Not that I'm anxious to implement it, but that's how I see it at this
time.

Yes, true, you couldn't clamp all that much! So a "free" clamp circuit
based on a motor "standby" wouldn't be appropriate.

I think the worm drive would provide stiffer back-gearing then the
timing belt drive, which as you observe, is needed here.

Interesting!

Alan KM6VV


rainnea wrote:

>
> Alan,
>
> In rotating a knife edge tool along the cutting path would you need
> to do some kind of look-ahead as opposed to taking the angle at the
> exact cutting point ?
>
> My 4th-axis is from a headstock (and tailstock when needed) off a
> taig lathe with a worm wheel replacing the belt pully.
>
> The way I'm using the 5th-axis for contouring, it's moving pretty
> much all the time as the tool traverses a curved surface, so clamping
> would'nt help although would be good for indexed cuts.
>
> Rab
>
> --- In CAD_CAM_EDM_DRO@y..., Alan Marconett KM6VV <KM6VV@a...> wrote:
> > Hi Rab,
> >
> > I was thinking about programming an axis that would always be
> tangent,
> > but I don't have any immediate need. I might need to move a knife-
> edged
> > tool along a toolpath, so it might be useful there.
> >
> > I was calling your 'A' axis worm drive spindle a "rotary table"
> when it
> > really isn't. Does the work of a rotary table 'tho. I use a rotary
> > table there, as I don't have a spindle mounted as an 'A'. Did this
> > start out as a lathe?
> >
> > How about a "clamp" for the 5th axis? An extra Mcode could operate
> it.
> > Or, perhaps the stepper driver could do the clamping, instead of a
> > "reduced current" mode for the motor, you'd engage the clamp
> (brake).
> >
> > Alan KM6VV