Trouble with scheduling

[Spritz1]

Hi i am trying to set up an accurate schedule for a project to get a projected finish date with the following information. I am using Excel 2003 with XP

Say 3 guys that work a 7-5 day (10 hours) are working on something that should take them a combined 43.7 hours leaving them with 13.7 hours to complete the following day. If they start on May 6^th they should finish the work on the 7^th at roughly 11:30 (13.7/3). They then have to do the same work on something else and need to start that after they finish the first one at around 11:30. That leaves them with 5 ½ hours each (16.5) to work on the next machine that requires 43.7 hours to complete. The following day (8^th) they will work on the same machine that required 27.2 more hours to complete. Once complete they will have a remaining 2.8 hours to start the next one and so on. The 3 guys will continue do to this on all of the machines until they are all done. I am trying to put together a schedule that is accurate enough to spit out a solid projected finish date based on the hours it takes to complete each task within a time from of 7:00am – 5:00 pm