I designed this little tea table (like a coffee table, but smaller). I got the top glued up and then realized I really didn’t know how to repeatably drill the compound angle holes for the legs.
I know this isn’t the standard finished product that most people post, but I wanted to share how some creative thinking and a fantastic CNC machine helped me make a drill guide fixture that would have otherwise been extremely tricky.
I definitely could have but I was using a 1-3/8" forstner bit for the hole since that is what I have (and designed the legs around) and it was simplest to just use that bit and not worry about the sizes matching up if I used the CNC
I’ll do my best to describe it using just words, but I can maybe make a video tomorrow if it is still confusing.
I modeled my tabletop on the cardinal XY plane, extruded into Z. I wanted the legs to splay in both directions but not equally. So I created a set of stacked offset planes (ie plane 1 is offset from the cardinal XY plane and plane 2 is offset from plane 1). I parameterized the two angles and played with them until the legs looked visually correct.
Just for discussion’s sake (and because I don’t recall exactly what those angles were) we’ll say they were -15° W and 5° P*.
So now I have an auxillary plane 2 that is canted in W and P relative to the XY plane. So I sketch and extrude a cube of the appropriate size which is bisected by my new plane 2. Using the slice command in Fusion360 I can turn one body into two using plane 2 as the slicing tool. Delete the unneeded top half and I have the solid body I need to take into CAM!
*The three cardinal axes are X, Y, and Z. Rotations about those axes are W, P, and R respectively.
I think I understand but don’t use Fusion360 and don’t think Maker can do that sort of thing. I think a video would be of interest to many and appreciated. I love using my machine to make router templates and such so this peaked my interest. What bit did you use to cut such a nice flat compound angle?
thanks again
I’ll try and do a quick screen record with some basic audio dubbing tomorrow.
I used a 1/4" flat end mill with roughly 80% step over and then hit it with an 80 grit pass on my random orbital. It was a bit scalloped before the sanding, but not much at all.
Very nice - I’ve tilted my drill press table for one dimension, and used an angle top for the 2nd dimension, but getting everything correct and repeatable was always a challenge. I like using the 1F to do the hard work, and keeping the drill press nice and square!
