Splines for slotting?

[GregHeumann]

Screen Shot 2020-06-29 at 2.07.37 PM.pngI have a goal of being able to design slot patterns for my microphone grills using splines. I have already been successful generating tool paths from sketches based on sketch slots, extruded into the grill body. 
 
I tried the same technique with some splines shapes and struck out so I went to a very simple experiment. I created a rectangle, extruded it. I sketched the top rectangle with the rectangle tool, the middle one with 4 straight spline lines and the bottom shape with the slot tool. Extruded each.
In Manufacturing, using the 2D Slot tool, it works as expected on the top rectangle and the bottom slot but it refuses to accept the center (spline-defined) rectangle. (I AM able to select it and it previews exactly the same as the other pockets.) But it says "Invalid Contours". 

What am I not getting?



Screen Shot 2020-07-02 at 8.51.15 PM.pngScreen Shot 2020-07-02 at 8.50.48 PM.png

[seth.madore]

The Slot tool is and has always been a "hit-or-miss" proposition, compounded even further by using Splines. If you can sketch the centerline of the splined feature, you will have great success with the Trace command instead.

[GregHeumann]

I tried a simple sketch w/ trace.- I can't get the machine to cut below the line I drew. The height settings don't include "bottom." Do I need to Project that line below the surface of a body or is there another way?

[seth.madore]

Axial Offset in the Passes tab

[GregHeumann · Accepted solution]

Thank you! I missed that one. It even traces the spline I drew at the initiation of this post. Now I have to learn how to create a new one that simply traces the centerline - I'm guessing I can do that by breaking this complete closed shape into the inner or outer and then offsetting it - but I'll figure that out - this specific design isn't that important to me, more about the learning. 

Screen Shot 2020-07-08 at 7.40.57 AM.png

[seth.madore]

You can also use Trace with a "Sideways Compensation" of Left or Right, depending on cut direction:

2020-07-08_10h53_52.png

 

[GregHeumann]

If it only had "inside" or "outside" that could help. But no worries - I've learned a lot, still learning plenty, books on order, etc. I actually cut metal for the 1st time yesterday with GCODE I didn't write myself. Simple part but major step for me. I know there are many ways to skin this cat. My goal related to this exercise is to be able to design more creative microphone grills for customers, including letters. (I've been using MACH3's text wizard for that - modifying letters that need "bridges" to keep centers from falling out manually.) But Mach3's tool path line doesn't help much with visualization of the actual result. (I cut through with a 1/8" end mill and don't expect that to change.)

Thanks again for all the help. I'm an old fart. I don't learn as fast as I used to!

[seth.madore]

Glad to help, and it's great to see customers make progress in their diving into this new world of CAD/CAM 🙂