As I mentioned perviously, I use a Ridgid Oscillating Edge Belt/Spindle Sander with a belt on to accomplish this. One challenge with this is that It's really difficult for me to set the table on the Ridgid to the exact angle I need (102.9°). If you look at the locking knob for the table, you can see why this is challenging: with one hand I'm holding the bevel gauge against the table and the sanding belt, with my other hand I'm fine tuning the angle of the table and trying to hold it steady, and with my third hand I'm trying to turn the knob to lock in the angle!
I tried this so many times, but could never get the angle exactly right. So I decided I needed to finally create a jig for making the fine adjustments to the table angle of this tool, something I had been thinking about on and off over the years. I also decided I'd try to make it out of only scrap wood as well as bits and pieces of hardware I had lying around in my shop. (I'm one of those people who, when I need to buy a bolt for some project, buys a few and tosses the extras in an odds 'n ends drawer or box. My shop has a lot of these drawers and boxes.)
I ended up making a mechanism that has rails that slide up and down in channels, uses table leg adjusters to set the height, and transmits the setting to the table via a homemade double hinge. Now, I'll be the first to admit that the whole thing is a bit crude—my friend Thomas, who is capable of making very precise parts and can even create working scale models of train engines, would probably make me do it over about a dozen times before calling it good enough—but hey, it works!
Here's a closer view of the double hinge.
Here's a view of the sliding rail and also the table leg adjuster. I came across these adjusters years ago and thought they might come in useful someday, so I ordered a few and tossed them in my jig parts box. The knurled knobs are quite heavy, spin up and down the bolt easily, and lock into place fairly effortlessly. I've never come across them again since then, so I'm glad I ordered a few when I did.
Here's the best part of the story. As I was gluing up the pieces of this jig, I kept changing the height of the table leg adjusters to make things line up better for whatever piece I was working on. When I had everything finished, I got out my bevel gauge set to 102.9° and lo and behold! the last random length I had spun in for the table leg adjusters turned out to be exactly what I needed. How crazy is that?!
Animation of double hinge in action