Design. Click. Build.

Proportions for Drawers--an Addendum

Thu, 30 Oct 2008 02:07:28 GMT

As requested, here's a bit of detail regarding the drawer heights from my previous blog entry.

After laying out the drawers using the Hambridge progression I ended up with a difficult set of dimensions to work with.

When I got finished, the overall height of the layout measured 43 31/64" high. The case in the dresser to the left is drawn as 44" high. The first step to getting reasonable drawer fronts is to scale the layout vertically. With the top of the layout aligned with the top of the case, I selected the entire layout followed by the Scale tool. Then I pulled the center bottom handle down to align the bottom of the case. Once you start moving the Scale handle, you can move the cursor over to the corresponding edge and click to set the Scale distance.

After scaling, the drawer spaces from top to bottom were 6 31/64", 7 11/64", 8 9/64", 9 41/64" and 12 37/64". I'd prefer to make the drawer fronts to more easily cut dimensions. I decided I would go to the nearest 16th of an inch. I started at the top and move the horizontal lines down to until I ended up with the following dimensions: 6 1/2, 7 3/16, 8 1/8, 9 5/8, 12 9/16.

As I mentioned in the previous post, I chose the reveal dimension and used Offset on each of the rectangles with that dimension. I chose 1/2" for this example.

This results in a 1" space between each drawer front so we need to modify that. I selected all bottom edges that needed to be moved and moved them down 1/4". Then I repeated that for the top drawer edges except I moved them up. I also split the top drawer in two.

The unneeded lines were then deleted.

And the layout copied to the front of the case. As before, Push/Pull was used to add a little thickness to the drawer fronts. I decided to add a bevel on the drawer fronts so I used Offset on each of the drawer fronts. I used a dimension of 3/4" for these. Then I selected the faces and while Holding Alt, used the Move tool to move the selected faces out 1/2". Alt invokes Auto-Fold which automatically adds the bevel and the lines at the corners. That's a very quick way to create a raised panel.

I think the result is pleasing and it it actually quite fast to do.

Dave

Proportions for Drawers--One Method

Sun, 26 Oct 2008 23:28:10 GMT

I was talking with a friend about methods for working out the sizes of drawers for a dresser. We talked about simple arithmetic and geometric progressions, the Golden Rectangle and Fibonacci's series. He mentioned one I'd not heard of by the name of the Hambridge Progression. This is a very simple way to create a pleasing layout for drawer heights. It's also easy to apply it in SketchUp

Here's a basic dresser design. It's sort of a massing study to get the exterior shape.

For illustration purposes I'm working out the drawer proportions next to the model. I just set out a few guidelines for this. I started with a square which has sides equal to the width of the case. Its top edge is aligned with the bottom of the case.

Then, with the Line tool, I drew a diagonal line on the square. I selected the diagonal and then got the Rotate tool. I hit Ctrl to invoke the copy command and rotated the copy up to vertical.

With the Line tool I drew a horizontal ine from the top of the rotated copy of the diagonal. One more line, drawn down the right edge, completed the recatangle for the first drawer.

I drew another diagonal from the same lower left corner this time to the new top right corner. That line was Copy/Rotated to vertical and then lines were drawn to complete the rectangle for the next drawer.

This was repeated until I go to the top of the case. Well, near the top. Then I adjusted the position of the top edge of these "drawer fronts" up to align with the top of the case and used Push/Pull to adjust the bottom of the case.

I used Offset to create the reveal around the drawer fronts. I used 1/2" for the reveal and then moved the horizontal lines to create a 1/2" space between drawers as well.

After moving the drawer layout onto the case, I divided the top drawer in two. Then I used Push/Pull, Offset and Move to add a bit of simple detail around the edges of the drawer fronts.

This is a very quick model and its long way from construction drawings but it certainly gets the idea of the design across. I think the drawer layout is nice in this tall case and hopefully it will get the approval of the client.

This method could be used for laying out dovetails. You could make a basic template, save it as a component and bring that into future models. A quick rescaling using the Tape Measure tool would size if for the project. You could pick out just the number of drawers you want for the project. You don't have to use all five.

Of course similar templates could also be made using other progression methods. Perhaps they'd be filed in a drawer spacing folder or something for ready access.

Dave

A Curved Rail

Sun, 05 Oct 2008 01:16:46 GMT

Recently I was asked about how to draw a curved handrail for a staircase. The staircase made a 90° sweeping turn about midway up the run. The fellow who asked me about this had tried to use Follow Me but the result wasn't what he wanted. The rail profile rotated about 45° between the start and end up the sweep. To draw the rail correctly we'll need a different approach. This method could be applied to a curved rail on a chair back and other sorts of bent pieces that aren't circular in section.

We start with the actual path of the rail. This consists of a couple of straight lines and a curve. While we'll need that path later, we won't use it for Follow Me. Instead we'll make a projection of it onto a horizontal plane. This can be done manually by placing vertical guidelines at the ends and at all of the vertices in the curve. Then lines can be drawn through each of the intersections of the guidelines with the plane. I used a plugin called Projection Tools to speed that up. The projection of the actual run of the rail becomes the path for Follow Me. After projecting the lines onto the face, I made the original lines a component.

The rail profile is placed over one end of the path. I put it at the height of the end point of the lower long line segment where it intersects with the curve.

Next, select the projected lines as the path for Follow Me.

Get the Follow Me tool and click on the rail profile.

Now we have a curved rail but it doesn't quite fit but we'll take care of it shortly.

After the Follow Me operation, the bottom of the rail is a single face. We'll need to break it up before we can move on so we'll orbit down low and, with the line tool, we'll connect the vertices of the inside and outside curves. These lines will end up completing faces inside the extrusion. We'll need to get rid of those later to make a smooth rail but for now we don't need to do anything with them. The next part needs to be done with Hidden Geometry visible so go to View>Hidden.

Next we'll select the end face of the rail with a double click of the Select tool. We'll get the Move tool and, while holding Alt (Option on Mac) we'll grab the end face at the bottom corner and move it straight down to the end of the original path line. Alt invokes Autofiold and allow us to move the geometry as we need to do.

Next we drag a left to right selection box around the rest of the rail to select it but not the part we've just moved. The trick here is that we'll select all of the horizontal part of the rail except the lines between the sloped part and the next face. Then we'll use Alt+Move tool to move the selected geometry up. We'll grab the selected geometry at the corner that corresponds with the next vertex in the path. We'll move that corner to the vertex and the rest of the geometry will come along for the ride.

We'll continue on with progressively smaller selection boxes and Alt+Move until the entire curved part of the rail as been fitted to the curved path.

The last step of getting the rail to fit to the sloped path will be just like the first. We'll select the upper end face with a double click and then Move that face up to the path.

Now it is time to get rid of those faces inside. If we don't do that, there will be a facetted appearance on the outside and we'll have some faces we don't need contributing to excess file size. I deleted the end face temporarily to show the first of the faces we need to delete. You can do that and then zoom into the rail to get at those faces or you can just zoom in through the side of the rail.

Finally we'll smooth the edges on the bottom of the rail and the rail is drawn.

I hope you can think of some applications in your drawing for this sort of technique. At the very least, perhaps it'll help you see that sometimes you need to combine various techniques to get to the end. It's a lot like working in wood, huh?

Dave

Another Use For Layers and Scenes

Sat, 27 Sep 2008 16:49:28 GMT

Recently I've been working on a very complex SketchUp model. One of the illustrations I needed to make involves indicating the location of a couple of lasers. Here's how I did it.

I drew lines to represent the laser beams in place in the model. These were made into a component and the component was moved to its own layer I called 'Laser'. The rest of the model was moved to another layer I called 'Router'. There was nothing left on the default Layer 0. Then I made two different scenes. One of the scenes had the Laser layer turned on but the Router layer turned off. The other was just the opposite. I modified the line style in the Laser layer so that Jitter was applied to the lines and I changed the color to red. When making the scene showing the laser lines, I made sure to choose the option for creating a new scene. It's important to make sure the camera isn't moved between scenes.

Next I exported the two scenes as JPGs. I got the following images.

Then, using Paint.NET, a free image editor, I combined the two images to create the following:

Click here to see a larger version of the final image.

This same method could be used to create an x-ray image of a part of a piece of furniture. For example you might want to show the inisde of a cabinet through the doors. You could make one scene with the doors not visible and a second with the doors displayed in X-ray mode and the cabinet not shown. Or perhaps you'd use this to make it easier to see how parts come together with joinery. It's very easy and quick to do and it can add an extra dimension to your presentation images.

You can get Paint.NET here.

Dave

Quantum materiae materietur marmota monax si marmota monax materiam possit materiari?

From 2D CAD to 3D SketchUp

Sat, 13 Sep 2008 19:05:40 GMT

Recently I had an e-mail from a reader asking me to show how I would make a 3D SketchUp drawing from a 2D CAD file he sent me. There are probably several ways to do this but here I'll show one way. Our reader wanted to end up with a model he could show to a client as well as something from which he could create shop drawings and perhaps a cutlist.

So to start. import the CAD file into SketchUp. In the import window, set the file type to ACAD and click on Options and set the units that were used when the CAD file was drawn. If you aren't sure as to what units were used, leave the setting and go ahead with the import. Then use the Tape Measure tool measure a know dimension to see if it is correct. If it isn't right, just type the new dimension and hit Enter. Click on the affirmative answer in the resulting message box and the drawing will be rescaled.

The imported geometry imports laying on the ground plane. Since this is a door that is supposed to be installed in a vertical position I'll rotate this to the vertical position. The reason for doing this now is that I'll make components of the parts of this door and I want the component axes aligned correctly. By rotating it now, I don't have to think about the axis alignment at all later.

There are several ways to get the rotation to occur on the red axis. I just orbited to a low vantage point and made sure I got a red protractor which I placed on the origin for the center of rotation. By the way, Ctrl+A selected all of the geometry.

After rotating the door it is evident that there are no faces. This is normal for CAD imports into SketchUp. We could just trace a few edges to heal the faces but I like to use a plugin called MakeFaces which makes very quick work of it.

Once in awhile a face or two will be reversed these can be corrected. Even after running the plugin, there are three missing faces in the upper part of the door. Zooming in very close reveals that the missing faces are due to some missing line segments. I've circled the gaps in the next image.

The gaps are quickly filled in with the line tool. When the gaps are closed the faces will be created.

After the faces are all generated, I copy them one at a time and use Push/Pull to add thickness. I make one part of the door at a time being sure to make that a component before moving on to the next. For components that have counterparts such as the stiles, I copy the first instance and them Flip it or mirror it. By copying the faces and building the 3D version of the door away from the original CAD import, I avoid the possibility of missing edge segments. This also allows me to use points on the original as references for the Move tool. For example, after making the first upper divider component, I copied it, flipped the copy and then moved it into place by referenceing a corner on the second divider in the original.

I worked on the parts by thickness. This allows me to use Push/Pull's double click option to speed up the development of the components.

After completing all of the door components the original import is deleted. Then it is time to start on the joinery. I copied the three horizontal frame members first. They'll get tenons and grooves first. Rather than moving the components away from the rest of the door for editing, I just copy the components and edit those. The originals, since they are related to the copies get edited too. Of course if you make groups rather than components of these parts, this process doesn't work.

When editing these components, I copied edge lines to delineate the grooves and tenons. Then Push/Pull made quick work of those details.

The next image shows the first haunched tenon on the top rail. I turned on the X-ray face style so you can see that the tenon has been added to the original top rail as well.

To cut the groove in the cloud lift edge of the center and lower rails, I selected the bottom edge and then used Follow Me on the profile below the tenon.

In the case of the cloud lift detail the Follow Me operation results in a few unwanted faces and edges. After selecting all of the rail geometry, run Intersect>With Selected and then delete the unwanted stuff.

Here are the completed tenons. The copies of the rail components are no longer needed so they can be deleted.

Next, I cut the grooves in the stiles. This was a simple matter of tracing the haunch on the tenon at the top edge and then Push/Pull down the length of the door.

To cut the mortises I just orbit around so that the camera is inisde the rail. Then I draw some lines to trace out the teon where it passes through the bottom of the groove. Push/Pull then pushes away the waste. This method of working takes a little practice and a sharp eye to pick out what you're looking for since your frame of reference is somewhat unusual. I find it faster than laying out guidelines or measuring for the locations of the mortises. Working in the X-ray face style helps.

In the next image I have dragged a copy of the stile out to show the first mortise has been cut.

Grooves and tenons are drawn in the vertical divider pieces and then the rails are edited in the same way as the stiles were to add the mortises.

Then the panels are enlarged to fill the grooves. On the straight sides, Push/Pull handles that task but the edges with the cloud lift details requires a different approach. FOr those, I drag a left to right selection box around the edge and use Move to move that edge the required distance.

As before, I copy the panel components out to work on them and then delete the copies.

The next image shows a section cut view of the completed door. All of the pieces have their joinery cut and all of the pieces are the right size.

The next step is to add some wood grain material to the components. The material I chose for this door comes in aligned horizontally so I started with the horizontal elements in the model. It's important to open the components for editing before adding the material. If you don't do this, you cannot modify the material for alignment. When opening the component to apply the materials, I triple click on the component so that all of the faces are selected. Then I get the material and apply it. Of course all related components get the material at the same time.

The material alignment is initially incorrect on the stiles.

So to fix that, select a single face in the component, Right click and choose Texture>Position. If you don't see the Texture option in the context menu, your material isn't applied to the face but rather it is applied to the Component.

Right click again and choose Rotate>90°

Then triple click on the component to select all of the faces. Get the eyedropper from the Materials browser and sample the face you just edited. Then click with the paint bucket on the component to copy the alignment to the other faces.

Then open each of the remaining components with a triple click, sample the material from the stile and apply it. Make the entire door into a component and save it for futre use.

Add some hardware if you wish and the door is ready for presentation. You could put the component in context if that's appropriate.

Since we made each part of the door as a separate component, creating an exploded view* is straightforward. We only need to move the components away from each other. Dimensions can be added as needed and a cutlist can be created. With the door drawn this way it would be rather simple to edit if a different size is required or other changes are needed.

(Click on this image for a larger version.)

*For new users of SketchUp, be aware that the Explode command in the Context (right click) does not create exploded views. The Explode command disolves the component or group "wrapper" of the component(s) or group(s) on which it is used. Caution should be excercised when using this function.

Dave