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I'm not sure that would work. The way the depth of cut is determined is by
plunging the cutter to a point where it's tangent to two sides of the outline
at the same time, for example, if the opposite side is 0.1" away and the cutter
is a 90 degree cutter, it will "slide" down 0.05" and in 0.05".
Original comment by pstem...@google.com
on 13 Aug 2013 at 5:19
Thanks for the explanation -�the intersection of tangents produces the medial
axis.
Maybe once a Depth Limit capability is working, the outside carve would be
possible.
�
For Depth Limit you probably already have it figured out, if not here is a
proposed concept.
The tangent lines are checked for length - if they are longer than the cutter
radius then two cut points are created instead of one medial point.
For example a 1" wide path using a .5" diameter 90 degree cutter would have two
points .25" along each tangent and at .25" depth.
�
For outside cutting I propose a concept�which uses�the depth�limit function.
It could be produced manually in CamBam as follows.
Draw a large bounding box around the full model - large enough so that no
interior parts are close to the bounding box edge.
Join the bounding box and interior parts into a "region" and�create the V-carve
MOP with depth limit.
This will create a V-carve path outside the interior model as well as a set of
points just inside�the bounding box.
Manually delete the path points adjacent to the bounding box -�remove from the
G-code using a text editor.
�
It could potentially be automated as follows if "outside" option is selected
for the MOP.
Calculate and draw a large bounding box (but not displayed).
Run V-Carve with depth limit to create outside path points for the model.
Ignore or delete�all points created�on the bounding box tangents.
�
If I can be of any assistance, please let me know.
�
Thanks - Bill Trondsen
�
Original comment by billtron...@yahoo.com
on 13 Aug 2013 at 2:09
That sounds a lot like just doing a profile operation with the cutter diameter
set based on the depth of cut and the cutter angle, i.e. cutter diameter =
depth*tan(angle/2) + tip diameter.
How would it differ?
Original comment by pstem...@google.com
on 13 Aug 2013 at 3:21
Yes, Profile does work in simple cases.
CamBam provides a pseudo-V-carve feature, when�Corner Overcut and V-tool are
selected a cut path is created into inside corners.
However the profile is not created if it detects a collision with another
object that is closer than the cut width.
For instance, if you have letters that are close together and use a wide tool
diameter, the profile will not be created.
A true�V-Carve MOP such as yours checks the distance to the nearest�object and
would be able to adjust the cut depth if it is closer than the tool diameter.
Thanks - BillT
Original comment by billtron...@yahoo.com
on 13 Aug 2013 at 4:42
Ok, I understand what you're trying to accomplish. I'll have to think about
that a bit. Currently the max depth isn't implemented because you can't clean
out a flat bottom with a sharp pointed v-bit. I might be able to generate a
inner outline that you could then pocket out with a square end mill.
I'm thinking maybe generate an offset line around the perimeter at a distance
of cutter width at max cutter depth, v-engrave between the perimeter and the
offset perimeter, and then create a polyline that tracks the cutter center at
max depth, which you could then use as a perimeter for a pocketing operation
that isolates the lettering.
Λ-engraving instead of v-engraving :-)
Original comment by pstem...@google.com
on 14 Aug 2013 at 6:52
Hmm. I don't think a fixed offset distance based on max depth and then
V-carving within this would work.
For instance if letters are close together this would result in cutting into
the adjacent letter.
I suggest the intersecting tangents should be constructed first, and then
using the tangent lengths the V-carve path points can be placed.
If the tangent length is shorter than the tool radius, then the one path point
is placed at the intersection of the tangents.
If the tangent lengths are longer, then the depth must be limited by placing
two path points an offset distance from each object.
For this to work for outside paths, I think a box is required to surround all
of the objects, unless you can calculate the tangents using infinite rays.
I can try to post some sketched examples if it would be helpful.
As you suggest, clearing the areas beyond the V-carve would be accomplished
using a separate pocketing mop.
The pocket offset can be accomplished using a roughing clearance value, so an
extra polyline for the V-bit path should not be necessary.
The roughing clearance would be set to the radius of the V-bit for a
flat-bottom end mill.
Or for a V-bit the offset can be set based on the depth of cut which gets the
pocketing in close to match the V-profile.
I have used a V-bit to clear the background and it leaves a really cool pattern
depending on how you set the region fill pattern.
For instance setting horizontal and then vertical hatching with a V-bit leaves
a pattern of raised pyramid shapes.
Or a ball-end tool can be used to create randomized patterns to simulate wood
grain (search forum for the texturize plugin by rodneyk).
Thanks again! - BillT
Original comment by billtron...@yahoo.com
on 14 Aug 2013 at 1:46
Original comment by pstem...@google.com
on 15 Aug 2013 at 4:41
Original issue reported on code.google.com by
billtron...@yahoo.com
on 13 Aug 2013 at 3:31