I built this grinder 4 years ago. I was my first ever DIY electric tool. Design is very simply, some parts should be made from thicker steel. Overall I bulit it with only 200PLN - 60USD in my pocket, including old CCCP made motor and some belts.
With this grinder I made all money to develop my workshop to current shape.
Machine can work with 50x2000[mm] and 50x2500[mm] belts.
There are also two videos on youtube about this grinder:
Those wheels from wood and PVC pipe works great, but they will never be as good as "real" contact wheels.
Plans for this grinder (metric) :