Tech Article ...by Dom Mauro
Learn how to properly balance your boat (Center of Gravity)...
These pictures show how the CG of every boat is a little different. The 3 Blast Cats below all have the same motor, same hardware and 2 have the same Aluminum Tuned Pipes and one has a Metal Tuned Pipe. All 3 Boats have the CG within 1/8" of each other. The pipe is placed in the same spot on the 2 end boats and they are all sitting in the same place on the Work Bench. The Blue Boat is the only one that has an extra layer of cloth, wish my purple one did.
Find your CG the Proper Way and balance the Hull itself. Forget about the Spark Plug to transom measurement.
Mark out and mount your Hardware to the transom, using a Sharp Pencil works best. Take your time using a Square, a good straight edge and measure twice and drill once. Once all your hardware is mounted place “everything” into the Hull temporarily. This includes an empty Gas Tank, Engine and Mounts, Tuned Pipe and Mount, Radio Box and Mounts, Servos, Battery, Drive Cable and anything else your will have your boat rigged with when its completed. You may have to tape some of the items in place into the Hull to hold them until you mount them permanently. Place a Magic Marker mark at your desired CG on the Keel and place a Brass Tube or Wood Dowel under your boat at your mark. Balance the Hull and all its components on its Keel on the tube by moving the motor and other internal components at your mark until the Hull will teeter totter or balance on your Brass Tube at your mark. The higher the powered motor the higher (more forward) your CG (Center of Gravity) should be set. Once the Hull is balanced mark the location of all the items and start building and mount them permanently. 30-32% balance point of the total length of the hull itself is a good number depending on how powerful your engine is.
Thanks and Good Luck!