Nest boundary in VCarve that accounts for hold downs

Hello all,
I wonder if anyone knows how to do this: Using VCarve, I would like to nest many parts on a sheet that has hold down screws inside the nest boundary. I put a picture below to show what I mean. The three circles in the middle are hold downs. I’d like to nest parts and not have to manually move parts around after nesting to avoid the hold downs. As far as I’m aware, I can only use one closed vector loop as a nest boundary. The only way I know would be to add a thin peninsula from one edge that wraps around the hold downs. This works but then it prevents parts from being nested across the this peninsula - That makes for a way less efficient nesting outcome. It would be so much better if you could use multiple vectors to define “no go” zones inside the boundary. Has anyone found a way to accomplish this?

I think you peninsula idea is going to be the best you’ll get out of VCarve. You could make the peninsula almost zero width, but I think you’d have some trouble teasing VCarve into getting it to pack parts around each side well.

It looks like you have all of the same part that you’re trying to nest?

While nesting is super cool (and handy if you need it) a lot of times I’ve found that just doing a grid array of parts can be just as efficient and yield better results.

You might be able to make two vertical rows of your parts and intertwine each row a bit, and then copy that row across the sheet. You could then just manually remove the parts that land on a screw. I suspect you might get greater yield that way than with a tight nest.

Another option is to use something like Deepnest:

Thanks for the insight Eric. I suspected as much. It’s too bad Vectric doesn’t provide the functionality. That part is actually just one of several parts of an assembly. I typically nest whole assemblies of parts. My little company makes dollhouses primarily. You can check it out at I’m designing little furniture right now. That’s one part of a dining room chair in the picture. Its actually makeup parts - I
screwed them up the first time around :stuck_out_tongue: Part of the reason they didn’t work is because the material has minor warp in it. It’s the nature of shop-made hardwood sheets. It makes for wildly inaccurate pocket depths when making parts that small/thin. That’s why I need the hold downs. I zero off the bed and try and hope that most of the material is on it or close enough.

I just noticed your suggestion to try deepnest> Will do! Thanks!

Let me know how that goes. Deep nest is pretty powerful, you do lose your layer info getting vectors in and out though.

Nesting is a hard problem to solve. Not only because it’s math problem but there is a lot of personal preference involved too

Maybe someone has already said this but when I use screws on a sheet sized project with lots of parts I draw my screw locations on the cad file. Then I run a separate file for those and just mark them about .125" deep. Nest then add them after.

Hi Erik, My process is similar. In the image below is the template I have and use as the starting point for making all toolpaths. Each one of those circles corresponds to a hole in the bed that has a threaded insert embedded. The bread and butter work I do is on 5x5 sheets of baltic birch. For the 5x10 bed, I use a nest boundary that divides the work space into two 5x5 sheets so the nest does not result in parts that cross over the sheets (the nest boundary isn’t shown here). After I nest, depending on how flat the sheets are I just pick holes that are in safe places and machine them out, then screw in a 1/4-20 furniture screw. So Vcarve and my machine always know where I can throw in a hold down. with big parts on big sheets there always ends up being a number of hold down inserts that fall between the parts of the nest. It works great and is worth it once you’ve put in all of those inserts!

But that process is less effective if you are nesting a sheet of very small parts with very little space between. What I’m doing now for that circumstance is nesting first, then moving the parts around manually to make room for hold downs where needed. I would love it if I could just include some hold down holes in the nest boundary though…

Most of you guys make me feel like a CNC savage! I just use sheet rock screws into the spool board. Could you not create sheets on Vcarve that would leave you rows where you want them? Again I’m sure this has already been thought of but just in case.

No no… wood screws in the spoil board are an old standard for me! And a number 1 go to in a pinch. The only reason I put that much effort in to have the inserts is that when I do production runs, it’s 44 to 88 sheets, all of which need to be held down around the edges at least, if not also in places in around the middle. That many wood screws makes for a very early death for the spoil board - not to mention, I think it can affect the surfacing. But in my view, you do have to have a good reason to not just use screws. If it works for you then go with it - It’s not savage or wrong in any way.