Macro Needed To Calculate Averages Referencing Time Clock?

Attached is a copy of my spreadsheet. I have been thinking about how to create a macro to calculate the average amount of material used per hour but I don't know where to begin! Each sheet(besides the summary sheet) contains a report that records when every time a piece of material was used. I would like a macro to sum up the total used by each hour on each sheet and place it in the summary sheet in the cell it belongs to to come up with the average of pieces used for each hour. Can anyone help this lost soul?