HOW TO mill a sloped pocket of arbitrary shape in CamBam

Finally! After two days of fidding and failing over a hundred tries, multiple exchanges with David, Bob, and some others, and a great deal of frustration, I figured out how to do sloping-bottom pockets bounded by an arbitrary shape, instead of just rectangular slopes. It requires both features in CamBam, and a little 'wet-ware' (human intervention).

The method uses the Curved Surfaces Generator, choosing the Flat Surface option.

The C.S.G. plugin uses a polyline corresponding to the SIDE of the slope (not one end or the other) to describe a sloped rectangle. It can only generate a slope from Z=0 down to a desired depth along the polyline chosen as the starting element. (I consider that a deficiency I'll fix, if given the chance.)

Choose a polyline length, and a 'width' setting sufficient to cover your entire bounding shape. Set your depth. In my case, I wished to go from Z=-0.5 to Z=-1.5, so I had to ask for a depth of -1.0. It will generate a sloped rectangle with engraving lines to cut that rectangle. If you choose 'generate MOp', it will also create an engrave MOp with all those lines described in the correct order - with NO optimization and zero depth-of-cut - to properly engrave the rectangular pocket with a sloped bottom.

But that doesn't solve the bounding issue. Next you have to do a few simple 'wet-ware' manipulations. The bounding shape must be a closed polyline.

Wet-ware:
First, move the entire body of engraving lines down to the desired starting depth. Numerical Move will do that. For my example, I had to move the array down in Z -0.5".

Wet-ware:
Next, check the position of the rectangular array with respect to the alignment with the edges (extremas) of your bounding shape. The edges of the array change depending upon the type of cutter chosen in the plugin. If your polyline describing the slope is the correct length, and the width is 'enough', then it will generate the correct pattern for any given tool profile selected in the C.S.G. menu. You really shouldn't have to do this step, but you know you will do it! If you don't like it, you can move it. It turned out OK for me.

Wet-ware:
Next, select the entire body of engraving lines, and select 'Edit/Trim'. Hit Enter to use your engraving lines as the object to be trimmed, and select your bounding shape as the 'trimming object', then Enter. Then select to 'discard (O)utside the bounding object', and Enter again. It'll take a while on a deep pocket. Fortunately, the 'trim' feature doesn't require actual intersections (contact at XYZ) of a line and the bounding shape. It only relies upon crossing the same XY coordinates to determine where to cut the line segments. Again, it'll take a while on a deep, fine-resolution pocket.

When it's done, you will have a NEW set of engraving lines - still in proper depth and sequenced milling order - that will mill a sloped pocket within your bounding shape.

Final Wet-ware:
Select your Engraving MOp for the original rectangular slope, and completly delete all the primitive IDs in the list (triple-click in the list and press Delete). It will then give you the option to select IDs. Select your entire body of trimmed lines, and hit enter. Those IDs will replace the originals in the MOp. If you have a VERY long list of them, the primitive IDs will NOT show up in the MOp (bug), but they'll still be there. Again, this step may take a while to execute.

You now have a MOp that will generate a pocket of arbitrary XY shape with a sloping bottom.

Final advice on generating g-code: CB ran out of memory trying to generate the g-code for two such fine-resolution pockets on my computer. I killed every application that was running except CamBam, and ran it again. It got through the process. It just needed that extra 4.5Gb of memory the other apps were using.

Lloyd

You are way over complicating it. Did you watch my video. All you need is a sloped surface in the right place larger than your pocket and a closed polyline for your boundary. Then standard 3D operations will do all the rest of the work.

I thought I saw everything you posted. I'll go back and look.

Bob, I submitted a reply to your post in the other thread. I simply cannot duplicate the surface or the milling operations you did in CB 1.0. I need the settings/numbers you used.

I used a rectangular polyline as the basis for extrusion, but I get what appears to be a 'solid', even when I don't select 'extrude solid'.

Perhaps a .cb file with a text explaination of the individual values you used for each operation would help me get there.

I think you have my email address.

Lloyd

Bob, I finally figured out how to make your example work. There was zero, nada, nothing visible in the video that showed how it was done, and the narrative didn't really describe what any of the primitives needed to be.

You must extrude a straight-line segment (polyline), not the shape defining the rectangular area you wish the slope to cover. Once you have that single surface defined, it's pretty easy to align, tilt, and otherwise adjust it to fit the application.

Thanks. That machines a lot faster than engraving scan-lines.

Lloyd

If I could, I'd edit that first post, but that's not possible. So all I can say is that it's one way that works. Bob's method is faster.
Lloyd

David (or anyone else), do you have a copy of the .dll for the Curved Surfaces Generator for CB 1.0? I looked, and can't find the one I thought I had. I had to use 0.98 to do the work I did earlier.

Also -- I've never used the Wayback Machine before. I can see a lot of references to CamBam pages there. How do I view old captured pages? Online searches didn't help.

Lloyd

Here's a link to it, https://www.atelier-des-fougeres.fr/...d_surface.html

Thank you. I snagged it there. I'll install it later tonight.

Lloyd

Quote:

---

Originally Posted by Lloydsp2

Thank you. I snagged it there. I'll install it later tonight.

Lloyd

---

There is a pinned post at the top here with links to the plug-in pages.

Quote:

---

Originally Posted by Lloydsp2

If I could, I'd edit that first post, but that's not possible. So all I can say is that it's one way that works. Bob's method is faster.
Lloyd

---

Due to spammers posting innocuous posts, then going back and inserting spam links, the 'edit window' time is restricted to 60 minutes. Unfortunate that spammers have forced this, but its the only way to get the spam down to a manageable level.

However, I can edit your post to make it read as you wish. Send me a PM with the 'complete' new content you want to see, along with a link to the thread it should go in, and I will replace the existing content.

Thank you. I had abandoned that thought, so let me get it collected again, and I'll PM you the result. I don't wish to misguide people having the same 'adventure' I did.
L

I'm noting here that I edited post #1 to reflect Lloydsp2's revised content.

Thank you!
L