I have built them out of pvc, they work pretty good but do not hold much corn---maybe 20 lbs. I have also built them out of a 55 gallon drum which not only hold alot more corn (about 500 lbs.) they last forever I have one that has been in use since 1996 with very little maintenence. I think I may have a rough sketch somewhere if your interested, I'll see if I can scan it in.