RE: Mission Impossible? Putting a pattern plane on a diet?
That's one heck of a man cave Tim [8D]
As Chris mentioned I had to shave some weight from his plane before the nats as well. It was the first full tilt 2 meter wood plane that his dad had ever painted and rigged, and he did a fantastic job. However without the experience, it left them a bit heavy. I went through and examined the plane and found that the only place I could remove more than an ouce was by changing the battery pack, and we needed 7-8 to be comfortable.
If you want to save weight on a large 2 meter plane, Bryan Hebert put it best a long time ago...get used to thinking in grams. because 28 grams make an ounce, and you have to take 4 here, 8 there, etc.
Example: Servo screws. they are tiny, how much could they weigh? Individually, not much. But how many of them are on a plane? 20? more? If you go to s maller size screw you may ony save 1 gram per screw, but multiplied by 24 or so, that's almost an ounce right there. Rudder cable rigging....linkages....control horns...trim every screw, downsize every nut. Every last one. get rid of those steel axles and wheel collars, that alone is 1.5 ounces heavier than central's aluminum jobs.
Look closely at everything. Could it be lighter? Usually yes. Not by much....so you have to get aggressive. the best way to accomplish this is when you originally build the plane, approach it like you know it's going to be 15 lbs and you're taking care of it up front. if you approach the entire plane this way, it's much more likely to be under the limit to begin with.
When it comes to balance, follow these simple rules:
1. remove weight
2. move weight
3. try #1 again
4. try #2 again
5. make certain #1 or #2 are out of the question
6. add weight
And when all else fails, especially if you're tail heavy, make a lighter rudder or set of stabs.
The scale is your pal...make friends with it early. it's your personal double naught spy, complete with iron hat. It will tell you everything you need to know, every step of the way. The biggest mistake is never using it until after you're ready to fly. by then it's too late.
Tim your header tank trick reminds me of something Nascar would do LOL but hey, I'm guilty of that one too. It's legal!
have fun...
-Mike