Bob If you are concerned about it, then I would place jack stands at all 3 places where the gear would be, or close to it, and then get a preliminary weight and balance, measured from the firewall. I encourage use of the firewall because it is in my opnion the most accurate place on the plane to take measurements from. Both Dan and I have stock KR2's and use the firewall as the datum. Dan and I talked at length one evening and went over all the points of CG and W&B and are completely in agreement. The only differences between our two planes will be actual construction distances in the end. We still both use the same are of CG forward and aft for the operating envelope.
It is my understanding, chime in Mark L. if I am wrong, that the AS504X wing planform uses the same CG enevlope, just a larger spar in some cases. So if you track how your CG is moving around as you build (obviously at the boat stage all in the rear ) you can insert an estimated weight of the engine, and station or location, and see where your CG lands, and make adjustments. At your stage it is better because you can eliminate, or mount differently something, instead of having to add weight later. By recovering the firewall to reinforce it, I also moved my engine forward 5/8" of an inch. Not a bunch, but every little bit will help with stability. It will be much easier to make adjustments with a more forward CG than aft. You can always us some are up front as a baggage locker and load it to help with final CG when flying two... (RV8's do this all the time. ask Dana Overall) Colin Rainey brokerpilot9...@earthlink.net
