FF Indoor
John Kagan [[email protected]]
The Art of Winding
WINDING RUBBER "motors" is another one of the Indoor FF art forms. Peak performance is heavily dependent on winding the most energy into a motor, but go too far, and snap! You have two smaller, useless bits.
After breaking a motor, it is common to hear the oh-so-helpful advice: "back off one" — a sarcastic suggestion to unwind to the point just before it broke. Getting the maximum amount of energy into, and then back out of, a motor is a tricky feat, but there are tips that can actually help before it's too late.
Use rubber lube. Lubricating the motor before winding prevents chafing that will cause it to break prematurely, and it lets more energy in and back out.
Rubber lube has traditionally involved special concoctions and guarded secrets. In times past, the preferred formula involved a base of glycerin and green soap. For many who grew up with it, that distinctive scent means "model airplanes" as nothing else does. It is still a decent choice, and it has the advantage that it can be washed off the motor if required.
These days, though, most people use some form of silicone emulsion/solution. It lasts a long time on the motor, doesn't weigh much, and is extremely slick. It is so slippery that care must be taken to find a knot that won't come undone. Some knots that work with glycerin and green soap will untie themselves before your eyes when silicone lube is used.
Silicone is available in many products, from hair spray to vinyl conditioner. My top-secret lube involves pouring Armor All (original formula) in a shallow pan and leaving it for several days until the liquid changes from milky white to a viscous clear. Put it in a dropper bottle and go fly.
Another surefire tip is to stretch the motor as you wind. It helps the knots stack evenly and allows more turns to be packed in.
How far to stretch and how fast to come in is a matter of opinion. For volatile rubber batches (such as 7/97), it helps to use a moderate stretch and come in well before the motor gets tight. This reduces the chance of overtaxing the motor and starting any notches that might cause it to break in flight. Then bring it up to peak torque once you've reached the desired final length.
For sturdier batches, I get better times when I keep the motor taut. It is easiest to watch the motor rather than the torque meter during most of the wind. Start coming in when the knots stack up, which happens at intervals. If done right, you end up with a rubber motor that has a neat row of knots and minimal "grapevining" (scraggly little sections sticking out on the sides).
The speed of the wind is also a matter of opinion. Indoor legend Jim Richmond takes forever, using roughly a 10:1 ratio winder. I vary but often find that winding more quickly gives me a better feel.
Either way, you want to go slower near the end. The beginning is less sensitive, but packing in the last few turns can be delicate. Slowing down lets the torque even out across the motor and may even dissipate built-up heat.
You can actually watch the torque drop as you let it sit after the first few times you bring it to peak torque. Repeat until the torque stays at the peak.
This brings us to using a torque meter, which is not much more than a wire, an indicator needle, and a dial face. You can build one fairly easily by referring to the article on the Indoor Model Specialties Web site (see the source list for the address) or buying a kit for not too much loot from Peck-Polymers. (Contact information is in the source list.)
A torque meter will help you approach a motor’s maximum energy storage without going over. Test a piece of similar-size rubber to failure, and you will have an upper limit. Just remember that a motor’s maximum torque will go down as it stretches and gets thinner after successive uses.
A torque meter will also give you a good way to back off turns to avoid outflying a given site with fixed-pitch classes. For maximum-duration flights, wind to max torque and then back off the peak portion of the torque curve. Backing down to a given torque, rather than just removing a certain number of winds, is an accurate way to hit your height target.
Finally, use O-rings. The ones we use are cut from hard plastic such as high-pressure tubing, nylon pushrods, or even plastic ice cream push-up sticks.
The rings are threaded onto the motor before tying and allow a fully wound motor to be transferred to the model without losing turns. It also keeps tight, slippery motors from zipping between your fingers and thrashing your model. (Guess how I know.)
If any of these tips are new to you, try ’em the next time you fly and see if they don’t help improve your times!
What is Hand-Launched Stick (HLS)?
Quite a few (relatively) HLS models have made appearances at contests across the country in the past decade. Steve Brown started the resurgence by breaking the coveted one-hour mark with one of these models in 1996, flying a world-record time of 60:01.
Max Zaluska recently made an HLS for the Lakehurst, New Jersey, venue, prompting Tom Iacobellis to bring his 15-year-old model out of storage. Jim Richmond built a new, lighter version to replace the one he left on the Akron, Ohio, blimp-hangar catwalk.
Don Slusarczyk put an HLS together for the US Indoor Championships a few years ago. My mentor, Jim Grant, had one that he flew to a record in the 1960s. I even hacked one together from old F1D parts.
Those who have seen these immense models in the air usually stare in awe, but those who haven’t may wonder what they are, exactly. Start by envisioning a Limited Pennyplane or Science Olympiad model; it’s small, sturdy, reliable, and easy to trim out and fly. Then go as far as possible to the other end of the spectrum.
HLSs are what you fly when you think you have this whole Indoor FF thing figured out. They’ll make you humble again.
With practically no rules restricting size and weight, HLS models are complicated, huge, and fragile. Wingspans typically exceeding 40 inches and weights barely surpassing those of a 22-inch F1D make them ornery beasts. Every name I listed pairs with a mental picture of his holding a collapsed model—and suppressing a wounded, but not broken, expression.
Constructing one of these aircraft is only a fraction of the battle. You still need to figure out a way to get it to the flying site. It certainly won’t fit on any airline, so plan on driving—if you have a vehicle big enough to hold the giant box, that is.
Then you have to fly the model enough to get it trimmed out. Ground handling can be problematic, with wings that barely hold up to flight loads. Steering at altitude carries the risk of folding it up, too. And forget about a hang-up. Any stall or dive invariably ends with a twist, a snap, and a collapse into a ball.
And once you have everything perfectly dialed in, you still need to wait for the right conditions—a delay that can extend into years. HLS models are a whole lot more sensitive than smaller models. Tiny drift for a 15-minute flight becomes a huge amount when you approach 60. But, as in any Indoor FF class, the challenge makes success that much more satisfying.
Only two people have flown more than one hour, and I’m proud to have joined Steve Brown with a national-record flight of 60:41, set at Lakehurst in 2001. Tom Iacobellis has since bettered that with 60:47, and Jim Richmond has several flights over 60 minutes as well.
FF Indoor
John Kagan
Ron Williams Book: Great news!
Ron Williams' Building and Flying Indoor Model Airplanes is back in print. Gone are the days of searching tag sales or libraries, or shelling out hundreds of dollars on eBay for a dog-eared copy. Now you can get your very own new edition.
He chose to keep the original 200 drawings, 60 photos, and 272 pages of text intact, even though the details of the various competition classes have changed slightly since the book was first published. The specifics are slightly dated, but the information and enthusiasm contained within are still pure gold.
Ron chronicles his journey from the beginner classes to the expert-level F1Ds. You'll learn everything you need to know to fly these delicate and enthralling models. He points out that there are many ways to deal with the various challenges, and he presents just one approach—but it's good and complete.
Best of all, this isn't a dry dissertation of technology. The book is infused with the spirit and passion of someone who clearly loves Indoor FF models.
Long regarded as the bible of Indoor FF, this book has lured many (me included) into a lifelong affair. If you enjoy model aviation of any kind—and Indoor models especially—you owe it to yourself to experience this work.
You might also consider using it to expose your kids, friends, or parents to this fantastic hobby. Find out more by visiting Ron's Web site. (You can find the address in the source list.)
Local Scene:
Don Ogren sent in the following report about the goings-on in Spring Hill, Florida.
"Even in Florida we can find fun indoors during the cooler months (Note that I didn't say winter). So here in Spring Hill, FL we have been able to obtain permission to fly once a month at the Lodge or the Performing Arts Center (PAC) at our senior community of 'Timber Pines.' Some of our group has been flying the small helicopters and mini-RCs, the RC Cessna's and Decathlons from ParkZone, and some are having fun with rubber power.
"The first picture is of our modelers, and the second one shows my indoor fleet comprised of No-Cal Goon, Smoothie, J-3 Cub, and a rubber band launched glider. Our ceilings are about 25-feet high, so we have a nice opportunity to get some good flight times.
"We haven't had any competition events so far—just getting together to fly. Most of us are RC modelers under normal circumstances. My J-3 had a midair with a helicopter last month; so needless to say, we have found a new shredder device."
Till next time. MA
Sources:
Indoor Model Specialties (508) 358-4013 www.indoorspecialties.com
Peck-Polymers (720) 833-9300 www.peck-polymers.com/store
Building and Flying Indoor Model Airplanes by Ron Williams www.indoormodelairplanes.com
Transcribed from original scans by AI. Minor OCR errors may remain.
