Nesting & Creating Cutting Tabs

Hello, I’m new here - I’ve recently ordered the Maslow CNC and will be building it in the coming weeks.

I’ve been doing a review of the toolchains that will be used, and have been thinking about how to try and optimise my use of 8x4 as I have very limited space to store sheets etc.

The nesting approach looks interesting, and in particular services like mynesting.com look affordable and much cheaper than the overall cost of buying / transporting / storing extra plywood.

I understand how the nesting works, but I’m confused about when the cutting tabs are added. Clearly this can only happen after the nesting optimisation, but which software step adds the cutout tabs. Is it the nesting software, or ground control or an additional intermediate step that I’ve missed?

Thanks,

Tom.

what software are you using? any “how-to” question will be specific to that
software.

David Lang

DeepNest might be an option for nesting software. It’s free and opensource and seems to work reasonably well. It’s also available for Windows, Mac and Linux. https://deepnest.io/

Vance

1 Like

Hi David / Vance,

I think I’ve answered my own question in terms of the process, with a bit of support from the MyNesting sales rep.

  • I’m using F360 to design plywood boxes.
  • I can use a free nesting script to lay all the pieces out flat, and then create a dxf.
  • I can then import that dxf into the MyNesting service (or deepnest.io), which will export a optimised arrangement also in dxf format.
  • I then have to re-import that optimised dxf into F360 again, extrude, and run the CAM processor adding the cutting tabs in the process.

When I get to it, I’d like to give both the Deepnest and MyNesting a go, side by side. I’ll report the results back here, as the MyNesting credits are about $7 per problem - so affordable, and could easily pay for the material cost saved (at least in the UK).

Thanks,

Tom.

2 Likes

well nesting typically doesn’t work that great for duplicate parts on a maslow because when you change the orientation of the part, the parts might not be exactly the same dimensions, especially if the parts are cut towards the bottom corner or top of the sheet. so if you need to have identical parts best to just use the middle 4x4 area and have duplicate parts same orientation

this video shows issues https://www.youtube.com/watch?v=fgeDcIxvd_E

1 Like

Thank you for this - very useful additional perspective. It seems that if it’s possible, one should cut the 4x8 into 4x4 and build a skirt either side, depending on how large the items to be cut out are.

Interesting perspective on the nesting - that actually it’s not a good idea due to the difference in tolerances in the X / Y plane.

unfortunantly the errors are not as simple as X being different from Y, the
errors on the maslow are curves, cutting top center, center, and bottom center
will produce subtly different shapes with the same g-code, even with the same
orientation.

somewhere in GC there is a simulator that will let you create error and show you
the difference between ideal and what the maslow will actually cut (for several
different types of errors)

it’s good to play around with that and see the types of errors that can happen
and how they can interact with each other.

standard calibration only considers a few possible error sources, holey
calibration considers a few more. optical calibration corrects for anything, but
is limited by how accurate a calibration source you can get/create.

David Lang

1 Like

the vast majority of projects posted can fit on a 4x4 sheet anyways. Raising the top bar to 30" above work area will reduce top center errors.making top bar 12’ long will help reduce bottom corner issues. any little bit will help if you do not have the headroom.

Ok guys, thank you for this. Seems the holey calibration is still in beta, and I’ve not yet built the initial unit yet.

The recommendation for raising the top bar height is an interesting one - I’ll have to see if I have the headroom in the Garage… I’m not sure if I do, but I’ll check. Presumably one could also raise it by 20" and that would be better than standard, but not as good as 20"?

Thanks,

Tom.

1 Like

play around with the settings on the spreadsheet at

higher corner tension is better, lower top center tension is better.

David Lang

For me, F360 does the tab creation during the tool-path development.

There’s a F360 tutorial out there that goes through each step of the tool-path/g-code development.
As for nesting your parts most efficiently, “nester” is a pretty good add-in/plug-in for F360 that takes your parts and lays them flat on the work surface to be cut. Then you can slide/rotate/adjust each part to tightly nest them (by eye) until your hear’s content.

km