Counterbores and dados at angles

[Ken Stevens]

I thought I would see if anyone here has a good description of how to draw within Sketchup, counterbores and dados which are non-perpendicular to the surface of the board (solid) in which they are to be cut.

I am a low-level intermediate SU user (can do a lot of the basics plus models with perpendicular surfaces) using the free version 6 of SU and am having fits trying 1) to put a series of counterbored holes along the edge of board (obviously in from the edge), the centerlines of which are tilted 8 degrees off vertical; and 2) pushing a simple dado along a surface with the sides of the dado being 8 degrees off of vertical.

Advice I received, and which I have tried with mixed results, is to draw a circle off of the surface to be "drilled", tilt the circle 8 degrees, push it into the board (very hard to specify an exact depth), then intersect with the model (I assume the board), and delete unwanted edges.

Well, trying this is nightmare! Positioning the circle so it touches the surface of the solid is tricky. Pushing it in so the resulting counterbore meets a dimension specification seems impossible. Then deleting lines without deleting part of the counterbore or a surface of the solid is also difficult.

Trying the tilted dado is almost as bad, but I succeeded, although properly positioning the tilted rectangle before pushing it was time consuming.

Long story short: anyone know a "easier" way to create counterbores with the centerline off of vertical?

Thanks for any suggestions,
Ken

[John Schreiber]

Ken,

I'm not sure I could visualize what you were talking about so my suggestions may be off base. Check the picture and SketchUp file below to see if I'm heading in the right direction.

8degrees.jpg 8 degrees2.jpg

8 degrees.skp

If that model relates to what you were trying to do, here's how I made them.

I first modeled the the board which would be dadoed and counterbored. Next I separately modeled an object the size of the dado, then rotated it by 8°. I then moved the object so the board and the dado shape were in the same space, made sure both were highlighted, intersected them, and removed the waste.

To make it so the two objects are in just the right place, use guide lines. First on the board, create an intersection of guide lines which will be the destination which you want to move the dado to. Then on the object which you will be moving, draw one or more lines on that, so you have something to grab it by. You can then select the object by the intersecting lines, and move it precisely to the intersecting guide lines on the board.

The counterbore might work the same way, except that you might want to make a disk, rotate it 8°, add some cross lines to it so you can grab it by its exact center, mark the board with the destination spot, move then tilted disk to the destination, then push/pull it to the length you need.

If I'm understanding the problem correctly and the text above doesn't clarify it for you (it looks clear as mud to me after I wrote it), let me know and I can draw it up as a tutorial in SU.

[John Schreiber]

And welcome to Sawmill Creek!

[Ken Stevens]

John: I am embarrassed as I did not look back here for a reply (the email subscription thingy does not work for me). I have been hanging out in the general area and just forgot to come back here and look.

I figured out how to make a dado at an angle, using first a solid "bar" the dimensions of the dado; then rotating it the required amount, then moving it into the board and then intersecting with model and deleting unneeded lines. Same approach with angled counterbore (simply a plug intersecting with the main board).

I wish this forum software had a mechanism to easily show you replies to your own messages; if you make a number (I am asking lots of questions), it gets tedious to look back in multiple forums or areas. Anyway, probably my newness.

Thanks for the help.
Ken