Re: Where should I head on a probe? (Was:Digitizer probe progress)

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "washcomp" <jeff@w...> wrote:

> Now that I understaand the flexability of a probe (thanks to
> Graham), it has landed on my "to do" list of things to obtain

and/or

> build. So I've got some questions:
>
> 1) Where do you find a probe or what major components for a home
> built one are redily available?

The DeskCNC probe is available for $275.00 with DeskCNC.
http://www.imsrv.com/deskcnc/probe.htm

It is also additionally discounted with purchase of our new Servo
retrofit kit ($150 with kit purchase) Information about this
offering is at:

http://www.cadcamcadcam.com/deskcnc/DeskCNC%20kitsa.htm

> 2) OK, lets say a probe is obtained/built. Grahams process to
> digitize an object is clever and works, but an easier way with less
> steps would be more useful for mear mortals like me. The ability

to

> find the boundries of a piece of material (for use as a reference
> point) would be helpful most CNC programs (MACH2 for example). I
> may be wrong, but it should remove the requirement to hand measure
> everything when beginning a new project.

You cannot eliminate measurement from the process of creating
precision parts. You can measure once and cut twice or measure twice
and cut once.

> 3) While I understand that tool paths will not be optomized, and
> tools/feeds/speeds will have to be hand entered, it would offer the
> oportunity for a CNC program to act as a duplicator.

DeskCNC will create an .STL surface file from a probed surface.
Since it also includes CAM functions, it will also create tool radius
compensated toolpaths to re-machine a duplicate, without resorting to
any external software.

> CAD) level, since only the CNC software has the ability to control
> the tool, this is the only loigical place to start. The ability to
> export the probed grid in a couple of popular formats for importing
> into CAM packages (DXF, etc.) may be helpful for those people who
> prefer to use their CAM software for better optimization and then

re-

> import back into the CNC system.

DeskCNC will export the data as an STL format. This is usable by
most decent Cad-Cam systems (like Vector Cad-Cam). It can also be
converted to DXF and many other common 3D surface formats with
Accutrans.

> What are proples views on the above and where do you think I should
> be heading/looking from this perspective.

The probing of 2D is basic math and can be accomplished with manual
intervention (like positioning to the center of a hole and using 3
point arc contact, to determine the center and radius). It does not
lend itself to automation and cannot automatically handle hole
tolerance. The probe cannot tell that a 1/4 hole is to be reamed vs
drilled or tapped. It is usualy faster to use a caliper and measure
the part than to install the probe in the toolholder and spindle, jog
to position and then precisely record each hole feature data.
Calipers only cost about $20-$50 so the efficiency is in the manual
technique. However measuring a complex 3D surface is another
matter. Hence the DeskCNC probing system.

Best Regards, Fred Smith- IMService

Listserve Special discounts and offers are at:
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