Partners In Torah

Parshas Hashavua נצבים     The last Mitzvah of the 613 Mitzvos is in this week's Parsha. "Every male has a חיוב to write & own a ספר תורה." It is very common for צדקה organizations to write a ספר תורה and sell  the letters enabling all who participate in buying the letters to become partners in the ספר תורה. R Akiva Eiger (Y.D. 270) quotes the Toras Chaim who writes, not to donate your ספר תורה to a ציבור if it's the only one you own. The Toras Chaim assumes for sure that a partner in a ספר תורה is not יוצא the Mitzvah otherwise why shouldn't he donate it to the ציבור which he is also part of and still considered owning part of the ספר תורה. The פרדס דוד originally held like the Toras Chaim that partners are not  יוצא the Mitzvah. He, later on, changed his mind and held the מנהג העולם of partnering in a ספר תורה is correct and all are יוצא מצות כתיבת ספר תורה.