Flip machining methods

[Jmcwoodworking (Joe Carroll)]

I’m having issues with flipping my project to carve the other side. I’m trying to follow @WillAdams advice from an earlier post:

“There are multiple ways to do this — my preference is to design the project w/ Center Left origin w/ top/bottom at the top/bottom half of the stock, then do the top half first using the origin as lower left, then do a flip rotating the bottom left corner to become the top left corner and using top-left as the origin."

@WillAdams when you say “do the top half first using the origin as lower left” Do you set x,y to lower left then carve? Once you flip stock do you then set x,y to top left before carving second side?

Apologies for beating the proverbial dead horse.

Thanks.

[WillAdams (William Adams (Carbide 3D))]

Yes, one uses opposite top (far)/bottom (near) corners as viewed from above so that the same corner is registered from for both cuts.

I’m pretty sure this technique is shown in the videos for using the Nomad flip jig (which is where I learned it).

[Jmcwoodworking (Joe Carroll)]

Thanks will check that out. What does using center left do while designing if you’re going to reset x,y anyway?

[WillAdams (William Adams (Carbide 3D))]

It affords the option of two different sets of models/toolpaths, one for each side.

[Jmcwoodworking (Joe Carroll)]

That’s what I thought. I tried setting center left and then set x,y to front left before carving in CM. When CM started it started cutting as if the center of the carve should be on the same horizontal plane as the front left starting point. What am I missing?

[WillAdams (William Adams (Carbide 3D))]

You need to have two separate versions of the design.

Let us imagine needing to make a design which has a rounded bottom and an angled top which is a bit less than 5" wide and 1" deep/tall:

The bottom design will be set up in the lower half:

Apply

Show 3D:

Next, we model the top:

Apply

Show 3D:

Then we set up two Toolpath Groups:

and rename as appropriate:

and create a second:

renaming as appropriate:

Duplicating the toolpaths:

Using the second geometry:

Then cut one or the other with the appropriate zero relative to the stock.

[Jmcwoodworking (Joe Carroll)]

Thank you Will this makes perfect sense now. I see the advantage of this approach.