Bookcase "bridge" design: Dado layout questions

[Greg Guarino]

This is a (very) preliminary design fro a "bridge" to join two bookcase uni ts I built. The bottom of this unit will be seen; the top and sides will no t. It would be approximately 48" x 23" x 12" deep.

The bottom drawing shows the face frame as it would be seen; the top drawin g is the plywood cabinet that would go behind it. I'm wondering if ...

1. The dado layout shown is sensible.
2. The dado layout shown will prove too complex for me to glue up properly in the allotted time.

Regarding (2.), I have made another diagram the shows the order I think I w ould need to glue up the pieces in:

First the 4 Red pieces Then the Orange piece Then the two Yellow pieces Then the two Green pieces Lastly, the Blue piece.

[aside: Did anyone else learn the resistor color code? And yes, I know I le ft out Black and Brown. And yes, I have heard all of the various off-color mnemonics for it. And no, I won't be reproducing them here] :)

Maybe the blue piece should go on earlier? I think maybe it should, but I'm too lazy to redo the screenshot. The clamping would be a little tricky too , especially with my modest inventory. Does anyone ever clamp a box like th is with it standing vertically? I'm guessing not; too easy to have it end u p twisted.

As always, advice would be appreciated.

[Leon]

Ok, here are the changes that I would make. Eliminate the bottom piece of plywood that goes all the way across. Going up to the three bottoms of each section, make that a single piece that goes all the way across to form the actual bottom and let it set in dados in the outer side panels like the top panel does. Basically make the top and bottom panel exactly the same and do not have the bottom panel on the very bottom. It will be much simpler to cut and dado if the top and bottom panels are identical.

Optional,

Additionally, I would cut dados and groves in the back of the face frame to accept all of the front edges of the plywood panels that it will be covering. And I always like to have a back face frame attached the same way too.

IMHO it is fine for the bottom to not appear all closed in.

If you go with my suggestion glue up would be a one step process for the entire carcass. It would be all dado joints so every thing would stay in place, starting with the center "H" section an finally adding the top, bottom, and sides.

Another hint, use Titebond II Extend glue for thus glue up. It gives you more working time and as always you should do a dry fit first.

I could provide a non scale drawing of how I actually do these type cabinets if you would like.

[SonomaProducts.com]

I am not sure why you have the two pieces so close along the bottom. I do see a small problem with dados in perfect alignment on both sides of the same piece at the center. I guess 1/4" dados in 3/4" ply is OK but seems would be good to avoid if possible.

I would assemble red. Then lay blue on table and assemble red into blue. Then roll over so it is on table as if looking down as pictures are drawn, then assemble and clamp the rest.

[Greg Guarino]

The other bookshelves sit on a set of cubbyhole units, and have 1x3 maple as the bottom of the face frame. I intend to carry this same "design" over for the "bridge", but the bottom of the bridge will be above eye height and will thus be seen. So the bottom piece of ply is to make the bottom of the unit flush with the face frame. The pieces above that will hold books and bric-a-brac flush with the top of the face frame 1x3.

Leon has suggested that this is not necessary, that the face frame can hang down below the actual bottom shelf. So far I don't think I like the (imagined) look of that. But at this point I may redesign the whole thing a few times before I build it anyway.

That's one benefit of having no spare time; you get to devote a lot of thinking to the project before there's an opportunity to build it. :)

[SonomaProducts.com]

So the bottom piece of ply is to

OK, knowing this then I would delete the second horizontal piece from your dado'd internal structure design. Then after you have that built and the FF applied you can just drop in some additional pieces, sort of like an adjus table shelves, in the space where that second piece would have been. Either put little legs on these pieces to hold them at the right height or lay in some spacers underneath.

[Leon]

Now if you would learn to use Sketchup you would not have to imagine how anything would look. You could see exactly, at any angle, how it would look.

[Greg Guarino]

With my (so far) simple designs, I think my ability to visualize is pretty decent. Having said that, I have done some Sketchup drawings of various things, and this design would be within my Sketchup skills. But after having built the main bookcases in the same style, I felt that 2D CAD would be more straightforward for sussing out the dadoes.

Maybe there's an easier way I haven't discovered yet, but the 3D nature of Sketchup forces it to "guess" which plane I want to move a component in, and it guesses wrong all too often.

Just last night I was trying to do a sketch of a simple open shelf with wooden (kind-of trapezoidal) uprights at each end. I drew one end piece, with the dado that would accept the shelf. Then I copied it, scaled it to "-1" to make a mirror image piece (there's probably a more sensible way) and attempted to fit the piece onto the other end of the shelf. That must have required four or five rotations of view, zooms and aborted attempts before I could get the component in the vicinity of the right location. Sketchup seems to take a perverse pleasure in moving the piece further and further from where I want it to go.

When 2D will do, I tend to use it.

[SonomaProducts.com]

Moving in 3D on a 2D screen has always been a difficult thing to emulate in any 3D CAD system (Ia m in the business and I know).

For Sketchup, I have found that to move you have to pick an exact point on the object you want to move and move it to another exact point on another o bject. You do this by picking on a corner and then again a corner. After yo u move it you can do a controlled rotation or two and maybe a slide move al ong an edge, etc. Trying to move freehand in 3D space is just too arbitrary on any system.

We are actually right now doing some study for using a paint brush type too l, like in photoshop where the cursor is a circle of a given size. We are s caling the size of the circle in realtime if are able to track the 3D objec t you are painting and add distance perspective. Difficult but pretty cool and necessary for the operation we are trying to support.

[Greg Guarino]

in any 3D CAD system (Ia m in the business and I know).

n the > object you want to move and move it to another exact point on anoth er object. > You do this by picking on a corner and then again a corner.

Sure, and that's exactly what I do. In this case I chose one of the inner c orners of the dado and the point at the mating edge of the shelf. And that works perfectly when the mating parts are already pretty close together. Th e program "gets" what I'm trying to do without much rigamarole.

But when I have to move a piece, say, to the other end of a 5' shelf, the p roblems start. There are only two dimensions on the screen, but the object can move left and right, up and down and fore and aft. All too frequently, I want it to move right, and it moves aft instead, to pick an arbitrary exa mple. So I reposition the "view" and try again. I frequently need to do thi s several times, hoping to get the part a little closer to where it's suppo sed to go with each step.

[Dan Coby]

You can specify the direction of a movement in different ways.

1) You can use the arrow keys. The right arrow key will lock the movement onto the red axis, The left arrow key will lock the movement onto the green axis. The up or down arrow keys will lock the movement onto the blue axis.

2) If you get a movement started in the direction that you want, you can hold down the shift key. This will lock the movement direction to be along the current path.

3) If you hover the cursor over an edge until you get the 'on edge' message then you can then 'lock' the movement direction to be along that edge by using the shift key. This also works for faces.

'Locking' a movement direction can be really useful when the amount of the movement needs to be specified by a surface or point which is not along the desired movement path.

Besides locking a movement direction, you can also place guide points or guide lines for your destination. You can also use the 'Measurement' window to specify the amount of movement.

The are probably other ways to specify a movement.

Dan

PS. Many of the different 'locking' or 'inference' rules also work for other actions like drawing or rotation.

[Leon]

It sounds like you are describing a situation that happens when trying to remain in a 2D view when working with a 3D program. Naturally the object may move along three different axis. When moving anything in a 3D program, especially Sketchup, you need to be viewing in 3D. Learn the program! You will be glad that you did.

The 2D view is for "viewing" and or adding dimensions or remarks. You do not want to be drawing or modifying in 2D.

Draw in 3D and then you can revert the view back to 2D if you wish. Once you learn how to draw properly in Sketchup it really really is a simple program to use.

[Leon]

AND as a follow up to what I just mentioned, always immediately make each piece of your project into a component before attaching/moving it next too another piece of the project. If you don't, both objects basically become the same object and that opens a whole new can of worms.

[Greg Guarino]

I was not even aware that there was a 2D view; I mean that the screen itself, and for that matter the movement of the mouse on my desk, only have two dimensions. If I move the mouse to the right, Sketchup "guesses" which axis I want to move the part in, and frequently guesses wrong. Likewise I have many times drawn a line that seems to be in the proper orientation only to find that it is somewhere else entirely when I rotate the view. It's like being in one of those "false perspective" rooms.

Just this morning, as per a suggestion here, I tried the arrow keys to restrict the movement to a certain axis. That seems to work. I'm going to try that when drawing (some) lines too to see if it helps.

I should say that I've been blundering my way through learning the program. I hate that the "Help" I found consists mostly of videos; it's simply too consuming of time I don't have to watch through a video (or several) to find the one tidbit I'm looking for at the moment.

Yup. That much I knew. It can be a pain to select all of the entities that make up a component when those entities are surrounded by other components. That's another operation that usually finds me swiveling the drawing in all directions to find just the right angle of attack. Perhaps there's a trick for that as well?

[Leon]

If you are only see 2 dimensions, height and width, you are in 2D viewing mode.

If the drawings of the "bridge" were done in Sketchup you were in 2D view. If you only see one side at a time and everything appears square on the screen you are viewing in 2D

If you go to the the menu bar and select View, Tool Bars, and add the Views tool bar you will get a tool bat that looks like simple icons that look a house. The first 3D icon of th house will put you in 3D mode all of the rest will put you in a 2D viewing mode. those show the top, and sides views.

When you are viewing in 3D moving along the correct axis is pretty simple.

FWIW if you type "O" for orbit you can click your mouse and you instantly move and view in 3D mode.

Likewise I have many times drawn a line that seems to be in the

That is because when you draw in 2D mode it is hard to determine if you are actually in front of or behind the object you are trying to add too or move to. 3D lets you see what is actually going on. Additionally when have drawn to or moved to a specific point, like the middle or end of a line you will get a small snap to object indicating where the modification is going to end up. When in 2D mode you may be 40 feet away and not realize it even though you think you are on top of the object.

The arrow keys help if you are in the correct location to begin with but if your 2D drawing is not on the same 3D plane they act like you are describing.

I can assure the video's are well worth the time spent. Pay attention to all of it as it sounds like you are really doing quite a few thing wrong. FWIW I had the same problems.

It could be your mouse that makes this a chore. I use a Logitech thumb marble track ball, I can orbit all over the place in a drawing, zoom in, pan, etc with out moving my hand. All done with clicks, and rotating the ball with my thumb.

And remember selection entities can be done by dragging a selection box around them. Click and drag from top left and drag to bottom right and every thing in the box is selected. Click bottom right and drag to top left and only those entities that are totally contained in the box are selected. That last selection method helps to not select a component that you may be adding another part too that is not yet a component. Still if you select too much you can always press the "Shift" key and click on the item you want unselected.

[Leon]

and another thing!!!!! LOL For drawing in 3D you are aware to use the push/pull command, right. It is the absolute best and fastest way to make a 2D object into a 3D object. In fact it tales longer to draw one side of a cube or box than it does to add the other 5 sides, unless you use the rectangle tool to make the first side.

[Greg Guarino]

I can assure you that I have never used Sketchup in 2D mode, unless one can rotate the object in any direction and see it from any point of view and still somehow be in 2D mode.

The drawing of the bridge was done with a 2D CAD program.

It hardly seems so, in my experience. If I'm looking at a side of the object straight on, then it tends to stick to L/R and Up/Down, but even a relatively small angle opens up a can of worms. The arrow keys look to be a very helpful tip.

That's what I do. But it's most convenient to draw objects using previously drawn objects as reference points. When there get to be a bunch of them in close proximity, it can be a drag to select only what you want.

Click and drag from top left and drag to bottom right and

[Greg Guarino]

I gave the arrow keys a quick try this morning. That looks like a very valuable tip. Thanks.

[Dan Coby]

I would also like to strongly suggest that you take Leon's advice and spend some time with the video tutorials. Trying to learn Sketchup by trial and error can be extremely frustrating. I gave up on the program after my first efforts without watching the tutorials. I had the same sort of problems that you have been describing. Much later I made a second attempt at learning the program. Things became much clearer after watching the tutorials and then doing some playing around. As Leon said, the time spent watching the tutorials will be well spent.

Dan