For design purposes where I often draw components and then remove them, I usually take the easy route and draw things as overlays rather than as a real part. But at some point you have to actually build something and that takes some type of joinery. I’m still an amateur, but I’m slowly learning. Doing the joinery in sketchup helps me see how things could fit together. So here is an example of how I do it (which I’m certain is not the easiest way).
When I start thinking about joinery, I start by thinking about the materials I’m going to use. For this design, I originally considered using plywood for the sides and back. In this case, the joinery for the sides would be easier as I could simply extend the plywood panel to the sides by ½” on either side and then move on to drawing the dados on the legs.
But since I want to use hardwood panels on the sides, then I need some more complex joinery and having a solid top and bottom rail is the first place to start. So the first thing I’ll do is move the original side panel out of the way. Note I’m not simply going to delete it as I’ll use it later as the base object for the two solid wood panels.
Once I’ve got the panel out of the way, I’ll start by making the top rail the full thickness of the stock I’ll use. I plan to use ¾” stock, so I’ll edit the top rail and pull the back until the whole thing is ¾” thick.
The next step is to go ahead and add guide lines to both sides defining the tenon position, in this case I chose a ¾ tall tenon offset from the front of the rail by ¼”. This will also define the bottom of the dado for the panels to sit in.
At this point, you have to make some decisions on how you want to build the part. In my case, I want the cloud lift visible on the outside of the piece, but I don’t want it visible from the inside as I think it will be distracting and the curves will stand out compared to more rectangular look of the inside between the shelves, legs, etc. So I know I want the cloud lift on the front, a squared off interior look and a dado for the panels and the panel center divider. This gives me some initial guidance on what I want to do.
I could have drawn the piece starting with small pieces and building the piece up from smaller sub-pieces until it looked like I wanted. But this is not what you do in reality, you normally start with a big piece and work by removing material, so when I do these modifications to the part, I’m going to always be thinking about how I would execute the removal on the saw. If I can’t think of a way to make the cut, then I’ve probably done something bad with the drawing.
So at this point, from an actual build perspective, I’m starting with the part at full thickness and the cloud lift on it. In reality, I’ll actually start with a square piece of stock and cut all the tenons, dados, etc first, then finish by pattern routing the cloud lift in order to maintain stability on the piece while doing the shaping.
So back to Sketchup. I want to confine the cloud lift to the front of the rail. On the back of the side rail, draw a line from one guide line to the other even with the tenon bottom guide lines. Then push that new face forward to be even with the guide line on the front of the tenon.
Now I want to define the back of the dado for the panel to sit in, so I draw a line on the bottom I just exposed from tenon corner to tenon corner. Then I pull that new rectangle down ¼” to form the back of the dado.
Next step is to define the tenon shape on both sides and pull them out to the desired tenon depth (I’m using ½”).
So at this point, I’ve got a top rail with tenons for attachment to the legs and a shallow dado. The dado provides a place to hold the hardwood side panels and a small tenon at the top of the center panel divider.
From a machining view point, I can now think about exactly how I would make this part. Starting from the ¾” stock cut to length and width, I’d start with the dado and then move to the tenons. The next step would be to pattern route the cloud lift and then make a pass to square off the back of the rail dado, removing the loud lift.
This is the basics of adding the joinery, from here it’s just the same basic process for each piece.
Continuing on, I also modified the center divider to hold the side panels. And here is the finished side assembled and then as an exploded view.
One of the other things I like about Sketchup is the 3D warehouse. There are a lot or user submitted models and you can find just about anything you need in terms of hardware. In my case, I drew in the aprons to mount the table top to, but I wanted table top fasteners. A simple search through the 3d Warehouse online produces the fasteners you see in my model.
So now we have all the joinery done and I’ve added a small beading detail to the ship lapped back panels. The look is slightly different inside the case, but overall I think everything looks good.
-- No honey, that's not new, I've had that forever......