D.S.
I have children at my preschool who are beginning to write their name (not perfectly) and others who are just beginning. Do not worry, he will get it with another year of practicing. I also have a kindergarten class. By kindergarten they know how to write their letters, names etc, (but trust me it is not perfect) some letters are backwards etc. By first grade better penmanship is expected. No worries. Something you can do to help is to write his name in dotted lines and have him trace the dots. This is what we do. Any worksheets with dotted lines to follow help develop writing skills. Also, lacing toys, sorting toys help develop fine motor skills and will also help writing, and can be more fun for them then sitting doing dittos. I wouldn't worry.