I have been trying to make G-code that will allow me to cut out a part in thin wood but leave a couple of hold tabs that would stop the part from popping loose when the outside cut is completed. I tried drawing the part in AutoCAD and making a couple of short segments on another layer that would be set to cut only part way through the material. Ideally for efficiency the cutter would perform the full depth cut, get to my tab and lift to just "engrave" and then lower without performing a lot of rapids. I believe that LCAM treats the tab cuts as another layer (which they are) so the are all cut as such.
Is it possible to cut a 1/16th " slot with a 1/16th" cutter using offsets in LazyCAM pro or does this send it into a "tizzy"? Can I engrave part numbers on my parts as well.
So far I have had a problem with Layers in that when I generate the offsets, inside and out and then delete the original layers, all Z's go to zero for rapids and cuts.
Can anyone offer a suggestion.
cheers
Jim

Hi, Jim

Using LC3.00.2 hear, Two chaines two different Tabs set.

Do your tool & off-setting and deleting first, Then set set your Z-levels on remaining layers.

Post your dxf will look at it, REPLY, Additional Options.

Hope this Helps, Chip

Thankyou Chip.
I worked through LazyCAM 3.00.2 again and found that if I worked onscreen using the zoom box I could select each item individually and work with the offsets. If I tried to use the full chain, i.e. inside/outside a lot of the small slots didn't work and sometimes the big items didn't either. I was able to make a clean job of it and used the send to all layers function for setting up the tool and rapid heights etc.
That was before creating the tabs.
The tabs as such are drawn as part of the item but with one small segment on a different layer. In the dxf file, the layer is called "engrave" as I would like to cut just .02" depth out of the .0625 material.  Creating these tabs on a different layer technically opens the polylines. I found that everything worked better if all of the parts where closed polylines. Is that valid thinking?  I will be using a 1/32" end mill.
Thanks again
Jim

Helmet fire time...
I just found the tabs button shown in your image. Does this mean that I don't have to create them in the dxf file?  Also I noticed that your file includes spline test, does this mean that the forbidden spline can be used too?
40 watts and getting brighter...

Hi, Jim

Yes, You should be able to do the Tab-ing, I think you have broken line segments in some of your cut-outs, I'll take a look.

As far as the splines hears the dxf for above pic, In my cad there short line segments, I think.

Thanks, Chip

Chip
I opened the dxf you posted and it shows up as a polyline which makes sense as you said it was made of short sections.  I have found that there are indeed a number of the objects that have broken lines particularly because I use the mirror function alot when designing parts.
Regarding the tabs, when the tab dialogue box says width and thickness, is the thickness how much the Z will lift or the depth of Z from the surface of the work which should be zero. In other words assuming work surface is zero, is the tab thickness to be -0.02 or .04 assuming the work is .06 thick? 
Also, how do you get that Isometric view in the LazyCAM window that shows the depths?
Thankyou for your time and effort Chip, this is really interesting.
cheers
Jim

Hi, Jim

Tab's Set the layer cut depth first, Then bottom cut line, Tab and set Tab Thickness & number of Tab's.

Use center mouse button, Press in screen and Move.

Thanks, Chip

Chip
Thanks for your very helpful and fast responses. I still have a lot to learn but you have really opened some doors.
cheers

Fan-tab-ulous
OK next brain teaser -  a few things
1.  Why do the tab heights disappear when I re-open the same Lazy Cam project
2. Why do the tabs always default to .25,.125 and 0  I am using mostly .05 thickness
3. Why are the settings of the current tabs on a chain, not shown when I select that chain again.
4. I did an oops on the last chain of a dozen or so and it dumped all of the tabs back to 0

It's a great feature but I am wondering if I am missing something. With the complex number of parts I am doing on one session, it is a lot of work to go back and re-do every item.
Thanks
Jim

Hi, Jim

Can you say "Bata Version", Don't now, I'd say do all your Tab's last.

You can save a finished LCAM file with File, Save As lcam, Dont now whether it will save Tab's though.

Brian's tied up now with some Mach3 issues, As soon as there done he's going to work on LCam some more.

Hope this Helps, Chip