Steve il certainly get a photo when I’m in my shop, but to be honest it’s built to Jerry Bennett’s original design! Except that I did not include the runner adjusting screw, and have never found the need! My sled is 19mm mdf! The runner is oak and the two fences are now also mdf. When I first built it at least 2 years ago, maybe more, it was accurate and I did several segmented builds at 24 segs and one ring at 48 segments all without problem. On a few recent builds at only 12 segments, I found I was having to true the half rings to get a good join. Not good!
Something had to be done and that is when I found that the front fence had a very slight bend in it about 3/4 of the way along. Just enough to compromise the angles. Clearly the ash fences were not as stable as I had expected. Mdf fences have solved are performing well, and I guess il just have to replace them if and when they wear. I don’t know how familiar you are with the concept of a two fence or ‘Wedgie Sled’ . Using a Wedgie Sled, one side of the segment is cut on one fence, and the other side on the second one. There is no “flipping” of the stock. Pretty much the only important setup is the angle between the two fences and it is this that dictates the the angle cut on the segments. The other important build consideration is that the front and back edge of each fence but be both straight and parallel so that the outer edges of the fence mirror the inner edges. This is where my ash fences went wrong. The inner edge of the front fence was bent ever so slightly therefore not flat, and this meant that the draughters square or Wedgie in my case did not accurately set the angle between the 2 fences. This the inaccuracies. I hope that makes sense. It’s more complicated to say than it actually is. If you google Jerry Bennet or Wedgie Sled you will find loads of videos on YouTube that will show the Sled and set up technique. I use mine on an Axminster TS 250, well set up and with a 60 tooth crosscut blade and get clean cut accurate and repeatable results that I do not need to sand other than remove fuzzies. Hope I’m not teaching my grandmother to suck eggs so to speak.
