I tried to mod. mine to turn it into a 3-wheel machine with a small wheel unit
but my design was complicated by the fact that the lower beam is not milled through on the inside channel, so the overall length of the machine is not adjustable to any useful degree. My idea would have worked with some tweaking but is a PITA to switch over and was not worth the effort.
I have considered getting the small wheel attatchment for mine, but the idea of grinding on the tension/tracking wheel just dosen't seem right to me for some reason. After giving it a lot of thought I ordered one of the EERF kits (have a few spare motors languishing, might as well put one to work) and am going to have a machine that is mainly dedicated to small radius grinding. I wish the EERF was availible when I bought my Coote, it basically gives you a KMG style machine with a Coote price tag, although it takes more work to put together.