Best way to mill corners?

BobCAD-CAM Software Discussions
#1

Hello,
this is the problem:

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Milling large contours with e.g. 3mm cutter have the problem, that inside corners remains with to big radius. In a second step, all inside corners should be milled with a smaller tool.
What is the best way to accomplish this task? I didn’t find an easy solution. Doing the whole job again with the smaller tool is time consuming and therefore not practicable. Defining separate contours that the smaller tool also last some time:
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Too bad there is not something similar like ‘Rest Roughing’ in ‘Advanced Rough’ operation that allows to mill overhanging corners with the smaller tool.

So what would you prefer do to it best at the moment?

Regards, Harald

#2

Hello,
It depend of cutting depth.
The perfect way use ф3 mm, turn detail and making sharp corner

#3

Hi Pavel,
can you explain closer? I do not understand:

Depth is depending on material thickness and is from 1-5mm. Afterwards done in 4 steps for 2.5mm depth:

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Bye, Harald

#4

so, end mill with diameter 1 mm isn’t good. Length too big.
I recommend make corner by mill ф3
After this turn detail and fixture horizontal
Then making this corner ф3 mm

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#5

Hi Pavel,
it is just a little bit difficult to do for 630 pieces on a 1000x2000mm plate.

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and genral for larger objects the feature would be nice to be able to rework inside corners with smaller cutters (e.g. rough with d=20mm cutter and finish with d=6mm cutter)
Regards, Harald

#6

Hi There MillingGuy did you try to use advanced pocket were you would add a dotted line to make it an open pocket then have a 2nd open pocket and click on rest roughing to do the corners with your smaller end mill?

1 Like
#7

Hi Eric,
no, I didn’t. Had no idea of milling a contour with a pocket operation. And to be honest I still do not know how to do it at all (dotted line, 2nd open pocket, …?)
Send the sample InnerCorner.zip (50.8 KB; zipped Rhino file). Can you put in the CAM strategy or show how to handle it?
Regards, Harald

#8

Hi Eric,
O.K., I did some research with advanced pocket: InnerCorner01.zip (78.8 KB)
Is it this you want to tell me (sorry, I didn’t get the point with the dotted line)?

Following issues:

  1. each drawn contour must be offset to at least the first cutter diameter.
  2. if cutter diameter must be changed (e.g. to get better result in overall speed or surface finish), all offsets must be redone
  3. setting the offset exactly to cutter diameter do not work, because of tolerance. the most part will be done in second stage with smaller cutter
    interesting: some partial lines are still made, although they are drawn with exactly the same offset as the others.
  4. the entire process is not a contour drive, but rather a pocket one. So the contour is driven twice to get all material removed. This is far to long for all parts to be milled.
  5. the second operations does milling on some “inner corners” which are not of interest, because just the inner contour defines the workpiece.
    image
  6. the entire process is too complex and cumbersome, where basically one contour run is enough.

Regards, Harald

#9

MillingGuy so everything you need to cut keep as a Solid line. You just need the dotted line to make it look like a pocket.Open Pocket - BobCAD CAM V30 - YouTube older video. Something else if you are going to run this in a Haas make your rapid plane .100 taller then your total Z depth InnerCorner.zip (104.8 KB)

#10

Hi Eric,

  • I got the trick with the dotted line. Didn’t find it in the documentation :frowning:
    In general I do not like software with Easter eggs… improvement of documentation is urgently desired/needed.
  • based on your sample I have had the turn out after some time (InnerCorner02.zip (54.5 KB)) with two approaches.
    Is it the same in Rhino setting line style to dotted/dashed?
  • Total also somewhat peculiar to drive with a pocket operation a Contour. And all the drawing/selecting of dotted lines doesn’t make things any easier. Especially when there are many parts to be made and then with more details as in my example.
  • It would be superb, having a rest roughing feature in profile operations, too => Click&Work :wink:

Regards, Harald

#11

https://bobcad.com/components/webhelp/BobCAM_RhinoV1/en/Content/Merge/Geometry_Selection/CAMGeometry_Selection_Methods.htm?tocpath=Geometry%20Selection|_____1

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#12

Hello,
yes, there it is. Despite reading several times, I would not have thought of being able to run a contour with it, which then mills out corners with a smaller diameter with the rest rough operation.

You have a lot of cool videos out there. The online help would certainly benefit if linking them in the appropriate places. Just a suggestion…

Bye, Harald