The most important part of any model build is making sure the CG balance point is correct. With a giant plane like the Top Flite Corsair, you need to take your time, or better yet, get the help of a friend to move the plane around.
Start with the plane in the maintenance cradle upside down. Notice that I added 25 inch long dowels as spreaders to position the balancer upright properly. I use the Great Planes C.G. Machine, for all my balancing. Right now, the gear are extended. For a proper balance position you need to retract the aft folding gear.
Now with the gear retracted, set the balancer for 5 3/4 inch back from the leading edge. Gently lift the plane from the cradle and position the balancer as shown.
Be sure to install the propeller you’ll be flying with and keep the fuel tank empty. For balancing, I use what ever is handy in the shop and place on top if the engine head until it brings the plane to level.
When the plane is level, the tail will lift out of the cradle. You have to set the plane so the fin/rudder hang over the edge of the workbench.
I use a digital postal scale to weigh the stuff I put on top of the engine to balance the plane.
Running some old Scuba weights though the bandsaw, produces some great ballast weights.
Simply weigh the lead until you get the same reading. I also drilled holes in the weight to fine tune the weight.
Make a mounting plate from some plywood, bolts, washers and blind nuts. I use Goop from the hardware store to glue the weights to the plywood plate and then add the bolts to make sure the weights stay put. Don’t rely on the adhesive alone.
Here the plate has been glued (with more Goop) to the engine standoffs and some cable ties have been added for more security. Shop Note: Make sure to provide some clearance so you can adjust the engine’s high- and low-end needle valves. My setup covered over the needles so I drilled a hole though one of the holes in the lead strips.
Now that the ballast weight has been installed, now is a good time to test run your engine! Let the Goop dry for a couple of hours before running the engine. After you set the needle valves and check the fuel flow, the airplane is ready for the cowl to be reinstalled. Then charge up your batteries and head to the flying field!
That’s it for our Exclusive Top Flite Giant Scale F4U Corsair ARF Build-along. Watch for the complete review and test flight report in the November 2012 issue of MAN…
If you want to add some detailing and weathering to your new giant scale Corsair, here’s how I did it, quick and easy: http://www.modelairplanenews.com/blog/2012/07/25/detailing-the-top-flite-giant-scale-f4u-corsair-arf/