This weeks assignment to make a joint with the big CNC proved to be a very challenging task. Getting the tolerances right mathematically stumped me a bit and it was hard to conceptualize what was going to happen in a 2D model in Vectorworks. You’d think a simple looking joint like a half lap would be easy to figure out — it wasn’t! I decided upon a half lap joint in order to make a short corner bookshelf. Once I got home though, I realized that the 90 degree angle I had planned to put the furniture was anything but 90 degrees. Now I think I’ll make a short TV stand instead for the midterm.
In Vectorworks I ran into a lot of problems figuring out where I needed to add tolerance and how to go about adding it without ending up with a solid filled shape.
Unfortunately the first attempt to mill didn’t work out because of a common problem placing the X axis all the way forward on the Y axis when zeroing out. The next day the I was able to start milling!
Mastercam was a bit of a nightmare this time around. It wouldn’t let me mill completely around the left square so I had to invididually set each side of the square which is why I think I ended up with a nasty looking edge on one of them. Also the mill didn’t cut all the way through my material even though I set the breakthrough to 0.05 and I rounded up my material thickness. I may chalk that up to the spoil board being pretty wobbly and the position of the wood on the machine was further back to avoid any X axis problems again.
After having completed my weird looking probably not a real sturdy joint skill exercise I’m a little freaked out about using joints for the midterm. I’ll definitely need some help figuring out how to do the math associated with tolerances and jointery in general.