Re: [CAD_CAM_EDM_DRO] Re:StlWork
Posted by
Alan Marconett KM6VV
on 2000-09-04 17:25:30 UTC
Fred,
Some time ago I sent this message to several USGS sites, looking for
information in understanding Hypsography data (DLG files). Do I
understand that StlTrans and StlWork can convert the .DLG data into
something useful for CNC?
I can read the data, and generate .DXF files, or .PLC files! But about
all I have been able to get is the elevation lines themselves. In order
to "cut" an accurate terrain, I need to do some sort of pocketing. Is
that what StlWork is able to do? Does It create all the toolpaths, to
cut a valley? Sounds like something I want to investigate.
How much have you done with .DLG files? Is this what you were talking
about?
Alan
From previous Alan emails:
Felton, CA. We have the specifications for this 4 MB file, and can
read/access the Nodes, Areas and Lines. We have written a "viewer" for
the file, and are able to view the data. What we would like to do is
create a model from a 4x8 sheet (stack) of plywood sheets, and display
the contours of the San Lorenzo valley. What is unclear is the
association of the data. Yes we read/see that their are Nodes that
relate (have lists of indexes) to the lines; and Areas that are bounded
by sets of lines. What is not clear to us is how to "transverse" the
data and "order" sets of contours to "cut" with a CNC milling machine.
To use a milling machine, one would want to cut the highest contour(s)
first, and remove all material at or above the contour level
(elevation). This would seem to require the direction of the slopes, or
perhaps the "neighbors" of each contour. Where can one find information
that describes these cartographic relationships? Or perhaps an
understanding of this field? We have read through some of the DLG
specifications to be found on USGS sites, but other then basic data
format, we are still lacking in knowledge of the "Graphics"
relationships in these maps.
Any insights or resources you may be able to share with us would be
appreciated.
addendum. Just open
the text file by selecting File-Open files of Type ALL, or copy paste
the text into
Vector using Edit-Paste Special, and select PLC data. The geometry
appears in Vector.
The data must be formatted in metric units, but it comes through very
nicely. Check
out the PLC article on the Vector web site. There is one shown there
that generates an
optical lens roughing pattern for a CNC lathe.
Some time ago I sent this message to several USGS sites, looking for
information in understanding Hypsography data (DLG files). Do I
understand that StlTrans and StlWork can convert the .DLG data into
something useful for CNC?
I can read the data, and generate .DXF files, or .PLC files! But about
all I have been able to get is the elevation lines themselves. In order
to "cut" an accurate terrain, I need to do some sort of pocketing. Is
that what StlWork is able to do? Does It create all the toolpaths, to
cut a valley? Sounds like something I want to investigate.
How much have you done with .DLG files? Is this what you were talking
about?
Alan
From previous Alan emails:
>We are currently studying a USGS Quadrangle HYPSOGRAPHY DLG map for
Felton, CA. We have the specifications for this 4 MB file, and can
read/access the Nodes, Areas and Lines. We have written a "viewer" for
the file, and are able to view the data. What we would like to do is
create a model from a 4x8 sheet (stack) of plywood sheets, and display
the contours of the San Lorenzo valley. What is unclear is the
association of the data. Yes we read/see that their are Nodes that
relate (have lists of indexes) to the lines; and Areas that are bounded
by sets of lines. What is not clear to us is how to "transverse" the
data and "order" sets of contours to "cut" with a CNC milling machine.
To use a milling machine, one would want to cut the highest contour(s)
first, and remove all material at or above the contour level
(elevation). This would seem to require the direction of the slopes, or
perhaps the "neighbors" of each contour. Where can one find information
that describes these cartographic relationships? Or perhaps an
understanding of this field? We have read through some of the DLG
specifications to be found on USGS sites, but other then basic data
format, we are still lacking in knowledge of the "Graphics"
relationships in these maps.
Any insights or resources you may be able to share with us would be
appreciated.
>Fred Smith wrote:
>.........cutdefinitions. These formats are covered in the Vector 6.0 manual
> PLC stands for Point-Line-Circle. It is a formatted text file with entity
addendum. Just open
the text file by selecting File-Open files of Type ALL, or copy paste
the text into
Vector using Edit-Paste Special, and select PLC data. The geometry
appears in Vector.
The data must be formatted in metric units, but it comes through very
nicely. Check
out the PLC article on the Vector web site. There is one shown there
that generates an
optical lens roughing pattern for a CNC lathe.
>
>...........cut
> StlTrans lets you visit the free archives of 3D shapes that are all over the internet, download a model of the thing you want to carve/cut/make, and translate it to STL so that StlWork can process the part. Typical forms that you might find are 3ds, dxf, binary STL, and vrml. Stl trans also has the ability to process USGS topographical map data and save the resulting data as a STL file. With this file you can cut a terrain map of major chunks of the world. The data is stored on the internet and much of it may be downloaded at no charge. I have a large stl map of the Grand Canyon that we will be making available at a later date. In order to make the canyon more visible, I scaled the Z depths by a factor of 10. This makes it more like a certain canyon on Mars, but it's easier to see.
>.........cut