If you have a 50' tree, you can't expect to cut it at 10' and have it survive or look anything like it's suppose to. Some shrubs that grow out of control could be pruned excessively, but if I want a 50ft maple to be 10 ft because it's filling up my gutters, that's not an option. Cut the whole tree down and replant something that won't get very tall. I have a feeling you'll be quite disappointed if you try something else.