Every knife I have made was done on a modified $100 WEN 4x36 grinder using belts made for wood. It is not nearly as nice or easy as using the right tools for the job, but my point is that pretty much anything will "work" if you care to put in some extra effort and concentration.
I bolted on a mild steel platen to raise the belt off of the flat surface of the sander, and cut plunges. The WEN sander comes with a small aluminum rest which was okay at best, but later I threw together a work rest from some metal plate and square tube stock and a few bolts.
Not to sound like an old "walked uphill both ways in the snow" kind of guy, but if it's all you have access to, then you can find ways of making it work.