Making a box with a design

WillAdams · February 18, 2024, 4:30pm

We start with a square which is the stock thickness:

We duplicate it, and move it into horizontal alignment with the original:

and then vertically align it with the front of the box which the second would be notched out of:

We then select the two squares and make as many duplicates as are needed to create 8 notches for the box bottom, and 7 notches for the box front using the Linear Array tool:

OK

Note that this makes one extra, which will be deleted:

We then select the squares:

and use the Scale tool:

to not preserve proportions and to set the width to the overall width of the box:

Done

which we then drag into alignment:

Repeat this for the other edges. Note that for the side it will be necessary to inset by the stock thickness, so duplicating this and dragging it into alignment will help in getting things lined up as desired:

OK

Again, there is one too many, so delete the extra:

We then measure to get the overall dimension for this:

and apply that using Scale:

Done

and drag it into alignment:

and replicate it as necessary:

arriving at:

which leaves one set of edges to do, which will require a bit of rotation and repositioning.

WillAdams · February 18, 2024, 5:21pm

and a further consideration:

The vital part I forgot was that, the etching would need to be reversed, as once it is assembled, the artwork would on the interior. If that makes sense? This will all be cut from clear polycarbonate.

So, no need to cut both sides.

Select the parts for the side:

and rotate 90 degrees:

Done

and drag into alignment:

For the sides we will want the front to have the full corner:

and the notch to be on the opposite side:

Select both:

and again use Linear Array to make as many notches (plus 1) as are needed:

Again, delete the unneeded one:

Select the squares:

and scale them to the vertical height needed:

Done

and drag into registration:

Select the elements for the side:

rotate and reposition:

and then duplicate the notches as needed:

For the unattached ones, it is simplest to copy-paste them in registration:

and then add the rectangle to the selection and Mirror Horizontally:

which can be repeated w/ a Mirror Vertical to fill in the top:

which give us all the geometry we need to define things, except…

WillAdams · February 18, 2024, 5:48pm

The problem is the geometry depicts what we want to remove, not what we want to keep.

Since Carbide Create doesn’t have a concept of a Composite Path with multiple pieces of geometry treated as a single element, it is much easier if one unions the design rather than attempts multiple subtractions.

There are a couple of ways to arrive at geometry which could be unioned — the easiest way is to just put everything on a separate layer and lock it:

and then draw in geometry which describes what one wants using the control key (command on a mac) to draw corner-to-corner:

Select All

and Boolean Union:

OK

Repeat this for the other parts:

It may help to increase a dimension so as to ensure overlap:

OK

Repeat for the last part:

and Boolean Union to arrive at:

Duplicate all the parts and drag them into position:

and if we were using a laser, we would be done with the joinery.

WillAdams · February 18, 2024, 6:23pm

If a toolpath was applied at this point we would get:

but the problem becomes clear when one zooms in:

Or, draws things up in profile:

The radius of the tool is half the thickness/width of the joinery — this is clearer if we model in 3D.

ThatPainterGuy · February 18, 2024, 6:40pm

Where there are “fillets” I’ll call it, in the inner joinery, would that not create an alignment issue?

WillAdams · February 18, 2024, 6:43pm

Yes, that’s what I’m working on a 3D model to show.

ThatPainterGuy · February 18, 2024, 6:48pm

Surely may not be the absolute best finish but, by adding a “hole” in each inner corner as a “relief pocket”, could potentially remedy this dilemma?

WillAdams · February 18, 2024, 6:58pm

Yes, doing a dogbone at each internal corner is one of the possible solutions.

WillAdams · February 18, 2024, 8:00pm

After a bit of programming we arrive at:

which shows how the parts would be cut, then we rotate one so as to make up the joint:

and adjust a few placement dimensions:

and get the intersection of the two parts:

As noted, adding dogbones is one way to address this.

ThatPainterGuy · February 18, 2024, 8:27pm

Are you able to demonstrate with the dogbones?

WillAdams · February 18, 2024, 8:36pm

If we hard-code adding dogbones:

Then we get:

But the appearance becomes:

which is kind of ghastly.

Since there aren’t too many, if one is patient and careful, a few quick passes w/ a file would work, or one could use a smaller tool, say a #282Z:

WillAdams · February 18, 2024, 8:46pm

Another option would be to use a suitable corner roundover tool:

it would still require a bit of filing, or machining a void.

WillAdams · February 18, 2024, 9:02pm

To add the dogbones, draw a circle which is endmill diameter plus 10%, so for a #282Z:

Use the Midpoint to drag it into alignment with a corner which you wish to modify thus:

duplicate it and align a few more copies:

Select the geometry in question and use Trim Vectors:

to remove what is not wanted:

until one arrives at:

OK

Then use Join Vectors to close things up:

and repeat that for all the other notches.

ThatPainterGuy · February 18, 2024, 9:24pm

#282Z, is available on the website?

WillAdams · February 18, 2024, 10:07pm

#282Z 2mm Single Flute ZrN - Carbide 3D

WillAdams · February 19, 2024, 1:13am

Eventually one arrives at:

The design can be shrunk down to fit:

but isn’t quite the right proportion, so will need to be adjusted.

For actually cutting the design, select all the geometry:

and offset to the outside:

Delete what one doesn’t want:

Then select everything and cut as a pocket:

Then select only the outlines:

and cut the outer profile:

(use an adhesive for workholding)

and you can use an MC Etcher or other suitable tool to engrave the design:

which should be mirrored:

and cut first.

WillAdams · February 20, 2024, 3:26pm

If the design is trimmed off to fit, but doesn’t quite work with the trimmed geometry:

It will be necessary to adjust things so that the design is properly nested.

This will be easiest if the box outline is hidden (easily done if on a layer)

Then it becomes easier to identify and adjust the elements which don’t quite work:

Go into Node Edit mode where necessary and cut open closed geometry which one needs to work with:

Select

and then delete the node

Done

Then draw in geometry to close things:

Then select and close:

using Join Vectors:

Repeat for all other elements which don’t work as expected for toolpaths.

WillAdams · February 20, 2024, 10:39pm

This also applies to open geometry:

Note that in some instances there is overlapping geometry:

which should be cleaned up:

Where there is open geometry which need to either be merged with, or separated from other geometry:

The most expedient thing to do is to separate it by offsetting to the outside the geometry it should be separated from:

Then using Trim Vectors:

to simplify down to just what is needed to close the region:

OK

Join Vectors

Deselect what one wishes to keep:

and delete to clean up:

Where there is geometry left over from a self intersection:

delete:

Apply the offset here as well:

Add the crossing geometry to the selection:

and use Trim Vectors to clean up:

Until one arrives at:

OK

Join Vectors to close:

Yes

Clean up by removing the surrounding box elements:

and delete

baricl · February 21, 2024, 12:18pm

Try this link. Takes all the work out of making a box.
Creates a dxf file that you can convert.

https://jeromeleary.com/laser/

system · March 22, 2024, 12:18pm

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