Making a box with a design

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

as requested on support…

Given a decorative file:

with the dimensions:

and wanting a box of the dimensions:

Height: 179.14mm x 188.14mm(ends/sides)
Width: 188.14mm x 368.14mm(top & bottom)
Length: 368.14mm x 179.14mm(front & back)

cut from a piece of stock:

Stock size is 47.8 x 23.8 x .25 inches

this would need to be set up as a two-sided job — so as to keep things simpler, we will use Center Left for the origin and arrange things so that top/bottom of the file will map to front/back of the stock:

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

To visualize this in 3D, we resort to:

https://www.blockscad3d.com/editor/#

which seems a reasonable proportion and to match:

which is the goal.

We will work out two different sorts of joinery — the relieved finger joints shown above and full-blind box joints.

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

First, we draw rectangles for each part:

(they may need to be rotated later)

and we arrange and duplicate to arrive at:

When the design is scaled to match we find it has the wrong proportions:

(which will be addressed later)

To make things a bit more manageable, we will divide and conquer and focus on the joinery for the present:

First consideration is the parts need to be separated enough to get an endmill in-between them (unless using a V endmill for the joinery — see below).

Since the stock thickness is only 0.25 inches (6.35mm) we have a bit of flexibility here — a #102 should be a workable size, so we will put 3.5mm in-between each part (that being a rounding up of the 3.175mm diameter plus 10%):

until we arrive at:

(the clever way to do this would be to set the grid size to match the dimension which we wish to move, or 10 times that amound and use the arrow nudges to shift things, holding down shift to move 1/10th the grid distance)

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

Next, each edge has to be notched for the box joints — note that this has to take into account the physical structure of the box and how the stock thickness interacts with the size of the joint projections.

to create the joints, I’ve divided the length by 15, width by 7 and height by 5.

Looking at the image, the front has full-length divisions.

In theory, one could create a rectangle the size of the long dimension, divide it by 15, then use the Linear Array tool to replicate it as needed, but in practice, rounding issues keep things from lining up.

A further consideration is that there are various online or other utilities for making such boxes such as:

MakerCase - Easy Laser Cut Case Design

and that this has been discussed before:

Radiused Box joints

We’ll try something a bit different here.

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

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 (William Adams (Carbide 3D))]

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 (William Adams (Carbide 3D))]

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 (William Adams (Carbide 3D))]

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 (Jesse McMahon)]

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

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

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

[ThatPainterGuy (Jesse McMahon)]

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 (William Adams (Carbide 3D))]

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

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

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 (Jesse McMahon)]

Are you able to demonstrate with the dogbones?

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

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 (William Adams (Carbide 3D))]

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

Using unsupported tooling in Carbide Create: Roundover / Cove / Radius bits

These are usually used in routers for decorative effects in wood: https://www.whitesiderouterbits.com/products/1570 but they are potentially useful for joinery: They are also useful for rounding off parts to allow rotary motion as for a hinged lid. Unfortunately, Carbide Create does not support this endmill geometry — but using the new support for previewing a V endmill when used in a No Offset Contour toolpath, it should be possible to preview them w/ confidence by stacking a series o…

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

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

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

OK

Then use Join Vectors to close things up:

and repeat that for all the other notches.

[ThatPainterGuy (Jesse McMahon)]

#282Z, is available on the website?

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

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

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

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.