? ? ? >> Each time the engine moves forward >> so does the distance of your new "arm" for calculating the new >> moments (weight on the three scales).
>Sure, it's a sum of moments either way. But why would you want to change not only the changed weights, but every other distance in the spreadsheet (or worse, your W&B sheet)? Now THAT's some bothersome math, adding whatever your new arm is to all those moment arms, rather than just the moment arm of the engine alone. That sounds like an increased opportunity for error, at least it would be for me. I know Larry knows this...just pointing it out... >Mark Langford >ML at N56ML.com >http://www.n56ml.com ----------------- As Mark correctly pointed out previous, Spinners come and go. In the last 1100+ hours, I've been through at least 5 spinners. Very few of them end up being exactly the same length, so you really have to consider the tip of the spinner to be a movable point, or a point that may not be there the next time you need to measure. The datum needs to be a reference point that will never move. Leading edge of the wing; bottom of the firewall; or as was pointed out previously; to keep the math easier by staying with all positive numbers, use an imaginary point with a fixed distance offset from a fixed point, like 5' in front of the bottom of the firewall. After all, you will likely be doing a new W&B periodically, so make it as easy for yourself as possible. During the build process, you tend to think in terms of getting the plane finished and it will always be the same once it's flying. I don't know about others, but over the last 20 years, I have made many, many modifications, additions, and deletions to my KR. Each of those modifications requires either a new W&B, or a modification to the existing W&B. In either case, you have to start out with a measurement from the datum in order to either update your W&B, or make a new one. I'll be doing a new W&B on my KR again tomorrow after changing out the engine accessories for newer light weight accessories. -Jeff Scott Los Alamos, NM
