I bought a used G1140 sander.. I want to add this type of pattern sander to it. I also like the BJansen version. Tenbrook Have you changed anything in this design or did you "get it right" the first time?? I have been using a Robosander with a tungsten carbide sanding sleeve for the last 3 or 4 years, which has worked well but the belt sander will be a lot faster.