rustnrot
08-20-2012, 10:10 AM
I thought I would post this since I have found very little info on how to cut an angle on the edge of a piece on the Shopbot. Many times it is dismissed with "easier to cut an angled edge on a table saw". A friend of mine wanted a hood for his kitchen remodel. Daunted by estimates having it made out of metal we decided to give it a go using 3/4" thick plywood. Plywood may not be the greatest choice over a stove so dismissing that, let's look at the details of building it.
I have also used this method for building folded horn type speaker enclosures with all the weird angles.
First I did a 3D model in Sketchup, pic attached (sorry but I had to make this .png file real small to upload).
After that, each piece of the model was laid flat in Sketchup for dxf export to PartWorks, machined side up. I show only half pieces since I actually worked with half a model in Sketchup and mirrored it in PartWorks.
Once in PartWorks, time to use the sketchup generated vectors to toolpath. The top edge was shown as a line, and the profile was generally, but not always, parallel to the top edge. The top edge was used to begin the red colored perpendicular "cut on vectors", the bottom edge was used to end them. One of the edges changed angle during the length. Try to do that on your table saw!
The FLUTING command was used to start the red vectors at the material top and then end at the material bottom (be sure and get the direction correct). I spaced these "flutes" .1 inch apart which gave a slight scalloped edge that filled easily with glue. The size of the 1/4" end mill I used is shown as a black circle and of course you had to be careful to offset these flutes by .125 inches from the top edge and end .125 inches away from the bottom edge to allow for the bit diameter.
The time it took to toolpath was measured in hours but compared to 3D work it was "easy motions".
Since I verified the fitup (with no gaps) in Sketchup, it all fit together perfectly using glue and a few brads.
I have also used this method for building folded horn type speaker enclosures with all the weird angles.
First I did a 3D model in Sketchup, pic attached (sorry but I had to make this .png file real small to upload).
After that, each piece of the model was laid flat in Sketchup for dxf export to PartWorks, machined side up. I show only half pieces since I actually worked with half a model in Sketchup and mirrored it in PartWorks.
Once in PartWorks, time to use the sketchup generated vectors to toolpath. The top edge was shown as a line, and the profile was generally, but not always, parallel to the top edge. The top edge was used to begin the red colored perpendicular "cut on vectors", the bottom edge was used to end them. One of the edges changed angle during the length. Try to do that on your table saw!
The FLUTING command was used to start the red vectors at the material top and then end at the material bottom (be sure and get the direction correct). I spaced these "flutes" .1 inch apart which gave a slight scalloped edge that filled easily with glue. The size of the 1/4" end mill I used is shown as a black circle and of course you had to be careful to offset these flutes by .125 inches from the top edge and end .125 inches away from the bottom edge to allow for the bit diameter.
The time it took to toolpath was measured in hours but compared to 3D work it was "easy motions".
Since I verified the fitup (with no gaps) in Sketchup, it all fit together perfectly using glue and a few brads.