I am trying to teach myself wheel building and I was practicing on an old wheel I have. I took the wheel apart and put it back together but the spokes were too long, I tried again following the directions on Sheldon brown carefully but the spokes are still too long. The front wheel of the bike is a 36 spoke 3 cross wheel. The rear wheel is 36 spokes and I think it is 3 cross but I may be wrong. When I tried to lace it 4 cross the spokes were much too short. Any ideas?

the wheel is a weinmann 519 36 hole 26in, the bike is a 1999 specialized hard rock FS