Here are the changes for Wright Stuff in 2001-2002
Division B: No changes.
Division C: Minimum model weight of 8 grams instead of 10 grams.

THAT IS IT!!!

Now the question you are asking is, how do I get to 8 grams this year?

Well the answer is quite simple, and not difficult to do. It will require a little more time and patience on your part, but the results are going to be well worth it. This page will cover the changes needed to get down to 8 grams. A brand new CD is not required because the techniques you learn on the CD are valid for really any type of rubber powered model. Only a few thing need to be changed to get you down to 8 grams, so here we go:

If you built the model per the instructions on this CD, and you used the proper weight wood and dimensions called out on the plan, your model should weigh in at 10 grams (or within 0.5 grams of that). If you take the red plastic prop assembly off of the model you will see that it weighs about 4 grams.  You can use the prop scraping method  described on this CD to get the weight of the red prop down to about 2.5 grams. If you used a large prop and cut it down to 20cm, you can still scrape it down to the 2.5 gram range and make it work. Any lighter than that and you are asking for trouble, since the prop will start to get too thin and flimsy and may not function properly. So by scraping the prop, you can shave off about 1.5 grams of weight right away.

You can also replace the .025" music wire on the landing gear with .020" music wire, this will reduce the weight of the wire by about 0.2 grams. Bringing your total weight reduction down to 1.5 + 0.2 = 1.7 grams. So your 10 grams model is now down to 8.3 grams with not much effort. This is about as far as you can go without having to build a new airplane.

Building a new airplane:
In an event that has a minimum weight, I always try to build the model underweight a little, and use clay to ballast the model up to weight. This has several advantages. First of all you can use the clay to fine tune the balance point of your model if needed.  Also as your model gets damaged from flying, the weight of glue from repairs starts to add up. So if the repairs get heavy, you can remove some of the ballast. I would try to shoot for 7.5 grams then add clay as needed to bring your model up to weight.

If you are building a new model, I would suggest using the reduced wood densities as called out in the chart below, along with the thinner wing spar and wing rib sizes as shown below. Remember, if you make your spars only 3/32" high you will need to make your ribs 3/32" high as well.  Using the reduced wood size and density table will easily take between 0.7 to 1.5 grams of weight off your model.

 Division C modifications to get down to 8 grams:

Description	Wood Size (inches)	Density (lbs per cubic ft)	Wood Grain
wing spars	1/16 x 3/32	6 to 7	A or B
stab spars and fin	1/16 x 1/16	4 to 6	A or B
wing and stab ribs	1/32 or 1/16 sheet	4 to 6	A or B
wing posts	1/8 x 1/8	10 to 12	Any
body	3/16 x 3/8	5 to 6	C
tail boom	1/8x3/8 tapered to 1/8x1/4	4 to 6	C

Covering Material:
You will be able to build your Division C model down to 8 grams using standard Esaki tissue as described on the CD. However, you may wish to experiment with lighter coverings. Gampi tissue is about 75% the weight of Esaki tissue. On a model like this, the tissue covering weighs about 1.2 grams, if you cover with Gampi, the tissue will weigh about 0.9 grams, a 0.3 gram weight savings. If you were to cover the model with condenser paper,  then the covering would weigh only about 0.4 grams, or a 0.8 gram weight savings. So if you are having trouble getting the models down to weight, you can try a lighter covering. The lighter covering does cost more. A sheet of Esaki is about $1 per sheet, Gampi and condenser paper are about $5 per sheet. Treat the Gampi and condenser paper just as you would the Esaki tissue. Theses papers need to be preshrunk and ironed as described in the covering section.

Final Notes:
You may find that if you apply all the weight reduction techniques outlined above, (lighter wood, scraped prop, and condenser covering) the completed model may weight in at 6 to 6.5 grams. At this point you should congratulate yourself on your fine building technique! You may also want to consider using heavier wood at this point! If you carry more than 1 gram of ballast, then you can easily turn part of that 1 gram into wood structure. A half gram of wood is a lot, and it can result in a much stiffer and stronger model, and still leave you with 0.50 grams of ballast to play around with. Once you become proficient at building light, you will realize that 8 grams is actually quite heavy and easily attainable.

Another topic I wish to brush on is prop repitching. There are really two schools of thought on prop pitching. Some think a higher pitch prop turning slower is better, and other think a low pitch faster turning prop is better. I can say both techniques work equally well. Those flying high pitch props tend to have shorter thicker loops of rubber say 15" of .093" with less turns. Those flying low pitch have long thin loops, say 18" of .075" with lots of turns. Is one better than the other? Not really. It is a matter of what you are comfortable with and what your model likes. Some people have been having much better success with long thin loops of rubber, others have just the opposite. Experiment with your model and see. The only thing in this event that really matters is the flight time, it does not matter by what method you did it. A 3 minute flight is a 3 minute flight, no matter if it was a high pitch prop or a low pitch prop.

The final topic I want to cover is rubber motors. All rubber bands are not created equal! Some rubber strip you buy may work better than others. It is dependent on many factors which are beyond our control. You may hear modelers discussing a 'batch' of rubber, like 'May 99' or 'October 97'. This refers to the date the rubber was shipped, and is typically found on the box of rubber when you buy it. Most modelers buy their rubber from FAI Model Supply and the rubber is marked with a date so you know what batch it is. Like wines and beer, there are good batches and not so good batches. So a model which may be flying poorly may be suffering from bad rubber syndrome! If you bought your rubber at a hobby shop, most likely is is not the best grade available. If you want good rubber, I would suggest going right to the main supplier, FAI Model Supply.

Also I want to encourage people to wind a few motors until they break. Many people believe the motor can not take any more turns, when in reality it can take quite a few more turns. I suggest you wind up at least two or three motors a few times, then try to see how many turns you can put in until it breaks. You may be pleasantly surprised! Also try to slow down when you get close to the maximum turns, winding too fast near maximum turns can cause premature breakage. In fact, many people stop winding near maximum turns for a few seconds to allow the rubber to rest, then slowly add a few more turns. You will find out that a few minutes of winding practice will help to give you a feel for how the rubber behaves as well as give you an accurate idea of maximum turns potential.

-Don Slusarczyk

A Design Modification:
For you experimenting types here is a design change you may wish to try.
1) Lengthen the tailboom by 1" (9" long instead of 8")
2) Make the stab chord 4" wide instead of the 2 5/8" called out on the plan.
3) Balance the model at the trailing edge of the wing (very important!), not in front of it as shown on the plan.

The larger tail and the further aft balance point may give you those extra few seconds you need to win!