Bill Sellers
05-30-2002, 09:52 PM
I have developed a simple Excel spreadsheet which can be handy for determining where to place all your boat components for analyzing where the center of gravity will be when it is built. This has some advantages for those of us who are analytical by nature and want to minimize the experimentation needed to trim the boat. This is a modification of a program that I used to help balance my model planes.
Of course the best way to know where your center of gravity is located is to measure it. This is easy with a plane because the CG is always on the wing and there are commercial devices that will help you to measure it. I haven't yet tried to actually measure the CG of my boat yet, but I have use the program to confirm that the CG is at the recommended location.
The spreadsheet has three tabs - Model 1, Model 2, and New model. Model 1 is my Miss T-Plus. I followed the directions of the instructions for component placement and it seemed to run well as advertised. I then measured the placement of the componets relative to the transom and the resulting calculation confirmed that I was close. Model 2 is my Oboy Oberto which I have just purchased the bare hull and the Dave Frank plans from RCMB. By using the location of the CG from the plans, I can determine the placement of all my components ahead of time. Then actual in-water running will fine tune the trim.
The New Model tab is blank and ready for anybody to fill in actual weights and location. In fact the other two tabs can be written over for re-use. They were just there for demonstration.
Having said of the above, I now find that I can't attach files with xls extension. ARGHHH!!! Maybe the friendly moderator can give me some help here, please.
Bill
Of course the best way to know where your center of gravity is located is to measure it. This is easy with a plane because the CG is always on the wing and there are commercial devices that will help you to measure it. I haven't yet tried to actually measure the CG of my boat yet, but I have use the program to confirm that the CG is at the recommended location.
The spreadsheet has three tabs - Model 1, Model 2, and New model. Model 1 is my Miss T-Plus. I followed the directions of the instructions for component placement and it seemed to run well as advertised. I then measured the placement of the componets relative to the transom and the resulting calculation confirmed that I was close. Model 2 is my Oboy Oberto which I have just purchased the bare hull and the Dave Frank plans from RCMB. By using the location of the CG from the plans, I can determine the placement of all my components ahead of time. Then actual in-water running will fine tune the trim.
The New Model tab is blank and ready for anybody to fill in actual weights and location. In fact the other two tabs can be written over for re-use. They were just there for demonstration.
Having said of the above, I now find that I can't attach files with xls extension. ARGHHH!!! Maybe the friendly moderator can give me some help here, please.
Bill