Some of our customers have had problems to get the EXTRA 330L balance easily with the lighter engines. We have flown 3 different prototypes with out any CG Problems, but some production models may have differences due to variances in balsa densities. We are not 100% sure as to why yet.

We have come up with some solutions that we feel are the easiest and most practical.

1. The 5 inch CG is quite conservative. In practicality, you will be moving aft. We have customers flying, finding out they are removing a lot of nose weight.
   
   
2. The 2 servos in the tail, did not pose a CG problem in any of the 3 prototypes. The fact is, that the two servo system as shown in the booklet, weighs a total 5.7 ounces. With a ratio of 4.5 to 1, saving 5.7 ounces in the tail is the same as adding 25.6 ounces in nose! I found that by changing to PULL-PULL on elevator saves over 2 ounces overall and the servo runs faster. The also moves almost all of the 5.7 ounce of mass to very close to the CG. Should be more than enough to get your plane in to CG limits.
   
   
3. If you choose to do this change, just provide us with proof of purchase and we will provide most of the hardware needed. Cable, links, extra Sullivan horns and a short instruction sheet.
   
   
4. We have put on the photos on our web site to help show you these ideas.

Click any photo to enlarge.
Step 1	Step 2	Step 3
Step 4	Step 5	Step 6
Step 7	Step 8	Step 9
Step 10	Step 11	Step 12

In closing, we first found out about this issue last Thursday and have been highly focused in trying to help you the best way we can. I think you will agree, the EXTRA 330L is probably the finest ARF available. We want to make to make sure you have as much fun flying it as we have … at least!

Fly safely and have fun,

Dave Patrick