Kitchen Drawers with finger or box joints

[ShowMe (Alan Hedrick)]

My first question.is; Is it a good idea to use a CNC to cut drawers for a full kitchen build? if not - we can go about this with the other shop methods.

If a good idea - I need some assistance in how to setup and adapt multiple sizes for the project. Would be happy to purchase a ready to use file to do this with.

QU2 Any one interested in helping me out. I’m Coachable!! But I’m new to the CNC world and have not dedicated enough time to become good at the machine.

Will be using 1/2 inch plywood with one UV side. Would prefer the finger or box joints to be hidden when the boxes are joined together. Average size would be 4” H x 21” D c 20” W. And I’d hope to be able to adjust the layout myself for different sizing.

I do want to learn and hope this might be a good start.

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

I’ve done traditional box joints using a vertical fixture before:

5-row storage box for MtG

but doing things thus has some notable cons:

• minimum of three setups: 1 - cut to size and machine internal features, 2 - mount all 4 boards and cut two corners worth of joints, 3 - rotate all 4 boards and cut other two corners
• possibility of orienting boards wrong when cutting joints
• exposed grain makes getting the positioning/Z-axis zero setting critical
• width/depth limited by height of table which the machine is on

My recommendation would be for full-blind hidden box joints instead:

Bamboo Pencil Cup

which allows cutting the entirety of the design with a single setup — one negative is that it requires a small/narrow 90 degree V tool and a matching (or slightly smaller) square tool, and this further means that the time spent machining is increased by the use of the small tools.

Now that Node Editing will snap to Grid intersections, it should be possible to set up a such a design for a given set of dimensions, then change to a different dimension for depth and width (but not height) so long as things snap to the grid. Hang on for a walk-through of this…

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

First, set up the file so that one can easily work with all the parts:

Draw up an overhead view:

The plywood bottom will be in-between the two rectangles which represent the overall size and the interior:

For reference, we draw the tooling which will be used:

• small V (1/8" 90 degree V endmill)
• large V (1/2" 90 degree V endmill)
• small square (1/8" square tool)
• large square (1/4" square tool) — note that since the stock is so thin, it should be workable to eschew the larger square tool, trading removing less material for slower material removal rate

and the joint:

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

The joint at each corner will have two sides which meet each other:

One interior feature which will be needed are rabbets which will hold the drawer bottom:

(the rabbets will need to be punched out of the upper portion of the boards proper when setting up toolpaths)

We create layers for each combination of tool and cut depth:

and the matching geometry:

and make a matching toolpath:

Repeat this process for each other tool/depth.

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

One concern is that the large V tool:

cannot cut the entire depth in a single pass, so cutting to either side at a partial depth will be necessary.

Done

Duplicate, align, then select both, duplicate again and add the matching part outline to the selection:

and mirror horizontally:

hide the other layers, select all, group, duplicate

then align to the top of the stock:

Ok

Repeat for the sides:

then make a toolpath to match:

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

Lastly, with the large V tool, a pass at the radius depth will be necessary:

Duplicate this geometry in registration to the other corners…

and create a matching toolpath:

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

A slightly complex region which will need to be defined is the removal of material above the box joint “fingers” so that it will not be necessary to radius them, or to add dogbones which would remove material weakening the joint.

It will be necessary to punch the geometry for the rabbet out of this:

OK

Select the outline for the part:

and offset to the outside by endmill diameter plus 10%

Assigning a suitable toolpath to this:

and we can begin to see how the joinery will be implemented:

There will need to be a placeholder layer for duplicates of the offset geometry:

which should be duplicated, unioned, and the duplicate moved to the small square to radius depth layer:

which now previews as:

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

Lastly, it is necessary to draw the hidden box joints.

These will need to cut away material to either side of:

in such a way that the matching halves of the joint will fit together, but will not protrude beyond the extent of the effectively 45 degree angled cuts which make up the full blind miter.

This will probably be easier in metric:

and will of course, require a matching layer:

We draw in a rectangle showing the minimum extent of the joinery:

and to make visualization easier, start by drawing in the outline of the tool:

The toolpath will need to travel up, left, up right to the center, up, right, up, left to the center, and then repeat.

Drawing in some squares/rectangles to define the extents of the motion will assist in drawing this out:

d

Done

Join Vectors

Yes

duplicate

Mirror Horizontal

and drag into registration with the original:

Clean up by deleting the reference geometry:

The two parts may now be selected:

and duplicated as many times as is necessary using Linear Array:

Ok

It will be necessary to delete one:

so that there is an even number of recesses on one side and an odd number on the other. Select them all:

and group

and then vertically align with the part:

Ok

Create a toolpath:

and then join the vectors into a single polyline:

and store the original on a reference layer, then duplicate the appropriate side at each end of each part.

Appropriate versions for each edge are easily made using Node Editing:

d

v

which previews as:

leaving only the matter of cutting the parts free at top/bottom or left/right.

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

Switch back to Imperial, and delete the unioned outline of the parts which makes the current toolpath preview possible:

It should then work to rearrange and rotate things so as to cut parts out:

Note that the geometry must not be grouped in such a way as to combine elements from different layers.

the parts arrange reasonably efficiently on a 2’ x 4’ sheet:

and the final toolpath which is wanted is a series which cuts the top/bottom of each part:

This geometry may be easily duplicated and aligned when this layer is active:

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

The bottom should probably be cut out with a larger tool, so as to save time, so:

Apply

Lastly, the toolpaths will need to be arranged and ordered adjust for optimal material removal — in particular, the small V to full depth toolpath should be cut last and may have its Start Depth set to the bottom of the joinery depth toolpath.

To adjust the draw dimensions, it is a simple matter of aligning a set of nodes on the grid:

Then selecting everything:

Going into Node Edit mode:

Select all the nodes at one end:

and then zooming in and shifting by multiples of grid units:

Attached as v8 files.

drawer_box_template_v8.c2d (276 KB)
drawer_box_template_NESTED_v8.c2d (320 KB)

Please test carefully and adjust toolpaths as necessary for fit.

[rogerwiegand]

For drawer joints in good quality plywood you can cut lock rabbet joints on the table saw or router table in a tiny fraction of the time. They are very strong, especially if you glue in plywood bottoms in the drawers. The lock miter joint is similar, but fussier to set up and make if you don’t want to see the joint at the ends

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

End grain is like a person’s belly button — you know everyone has one, but it’s only for certain special people that one wants to see it.

[cnackers (Chris Nackers)]

If you use Vetric Vcarve there are multiple drawer plugins that’ll calculate everything out for you and do a modified dovetail (since you are cutting from the side instead on vertical). You just punch in your drawer dimensions and it’ll spit out all the files and tool paths. There are cabinet ones as well, lots of support for this type of thing.

Just as an alternative. You can obviously do it with CC as pointed out above but if you want to just make it simple there are options out there.

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

I’ve been working on automating this sort of thing:

We’ll have to see what happens in the future.

[cnackers (Chris Nackers)]

Nice!!! You guys should add it

[Ed.E (Ed)]

There you have it @WillAdams, two votes “yes”…

[Emmess (Matthias Solga)]

Check out easel cabinet designer from Inventables, they say can work with Shapeoko:

[rogerwiegand]

I don’t know about belly buttons, but I’m pretty addicted to drawer joints that look like this with end grain in full glory.

That was the first drawer I ever made in my youth, many decades ago. No power tools or computers involved (yes, they HAD been invented!). I still like it.

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

That is a good example of a special occasion when seeing endgrain is wanted.

Not quite as visible, but I handcut the dovetails for this Ascham:

Archery Case (Ascham) --- interior

[allanschwartz (Allan M Schwartz)]

I did all of my garage drawers (and even the cabinet) cut on the CNC.
An example is here:
Easel - DeWalt cabinet drawers 16.25 x 20.75 x 4.25
wherein, i outfitted each DeWalt planer stand with four drawers. If this were my kitchen, I would do the same, but cut it out of real Birch Veneer (instead of Home Depot Sande Ply).
Using Easel, it takes only about 10 minutes to do the design, and about 30-45 minutes per drawer to carve. I was unable to do this using Carbide Create, without external tools.