Re: how the heck to peck

Hi Jan,

I have already figured out how to do the X Y so that part is not too
tough. There are a lot of ways to do the table movement.

So I am going towards a full CNC machine.

Since the tiny drills will be in aluminum or plastic (PVC)
moving the parts is the easy part.

In PVC, the drills bind if the material gets hot and there is heck to
pay with a stuck drill. in aluminum, the chips mess with the lip of
the hole. In aluminum the peck is to keep the entrance hole sharp,a
nd in PVC it is to keep the bit cool enough to eleminate melting.

Since I am using a PC to move the parts, I can control the motor
actions.

Seems like a chain will be the easiest to do now as I can get that
pretty easily, and a smaller stepper would offer more torque when the
gearing is used. I'm sure that chain wear will throw some curves
down the road, but it may not be too bad of a problem.

Since I'm doing through holes, there is no problem with depth.

I'll be more than glad to hear any other suggestions or maybe some
links to what has been done.

Dave

--- In CAD_CAM_EDM_DRO@y..., JanRwl@A... wrote:
> Dave:
>
> Do I understand you right that you want to "motorize" only the
quill, and not
> really turn the drill-press into a "CNC machine"?
>
> If I needed to do this, I would use some Berg Min-E-pitch type
> chain/sprockets and a stepper-motor, with a home-brew pulser with
thumb-wheel
> switches or the like, to make it possible to set the number of
steps AND
> step-rate DOWN, and "rapid-traverse UP" (this latter would be about
400-450
> SPS).
>
> Or, these days, surely less time to do: Use the parallel-printer
port of a
> "throw-away" PC (but a working one!), and write a BASIC program
which would
> "toggle" the bits of the port - like, bit-zero and bit-one - for
driving the
> stepper-driver CW and CCW. The RATE can be done with "do-nothing
> delay-loops". If you are not familiar with at least GWBASIC, there
is little
> point in my putting an example of what I mean, here.
>
> If this drill-press would be used for "other stuff, too", you could
design
> your mechanical attachment cleverly so that it could be "swapped"
with the
> up/down handle, rather than just REPLACING it, making this, then, a
> "dedicated" machine.
>
> Jan Rowland