Re: Modified G78 pecking ?

Dave,

One of my controllers has a very slick peck drilling cycle, I don't
think it's RS274 standard. You specify the depth of the first peck
and each following peck is reduced in depth by a user specified
percentage. For instance..specify the first peck as 1" deep, with a
percentage of 80. The second peck would be 80% of 1" or .8". The
next peck would be 80% of .8" or .64". You also specify a minimum
peck depth so you don't get extremely small pecks as you go deeper.
The drill retracts fully between pecks.

I've used the cycle to drill some nightmares.....like very small,
deep holes in clear plastics where the hole ID has to be smooth and
remain transparent.

Since my other controllers don't have this cycle I hand code it when
needed. For really critical hole work I'll add a pause while the
drill is retracted so coolant pressure can blow chips out of the
drill flutes.

Doug

--- In CAD_CAM_EDM_DRO@y..., "turbulatordude" <davemucha@j...> wrote:
> Hi,
>
> G78 calls for a drill pecking that uses a full retract on each peck.
> The holes I am drilling only need to have the drill retract to let
> the chips ride up the drill. The small up then down lets the chips
> out of the hole quite successfully.
>
> Is there a multi-stage peck ? one that would start, approach the
> part, drill, withdraw a little, then continue drilling for the
> pecking cycle, then withdraw fully ?
>
> Something like drill 0.02", withdraw 0.01" the take another 0.02"
so
> that the top of the retract was only slightly above the last
drilled
> hole and not fully to the start ?
>
> or is my best bet to move the Z to just above the part and peck
from
> there ?
>
> My problem is drilling long holes in aluminum with tiny bits. 3/64
> drill into a 1/4 inch plate. it's 6063 aluminum so it's kinda
> sticky, but produces long chips.
>
> Dave