Rag-a-muffin

An Airplane Anyone Can Afford

by

Roger Mann (EAA 352591) EAA Experimenter December 1995

Webster’s Dictionary defines a “ragamuffin” as a scruffy child. In my mind this doesn’t mean that the child is unhealthy or handicapped but only that the child has smudges on his or her face and isn’t wearing the best clothes that money can buy. Keep this definition in mind while I describe my Rag-A-Muffn…

My Rag-a-Muffin happens to be an ultralight aircraft. I call it this because it doesn’t wear the best paint. It wears latex house paint And, it doesn’t have what is considered to be the best powerplant – a Rotax 503. Instead, it uses the readily available and mass produced Kawasaki~ ~ engine. The complete and total cost to get Rag-a-muffin flying was $1,644.99. Yes, that is in 1995 dollars. Serving as an EAA Technical Counselor, I’ve been around homebuilders long elnough to know what their most important questions will be. First, how dependable and affordable is the engine? Second, how strong is the design? Third, is the coverng system safe and how long will it last?

I will cover these questions in the following text which will describe how the Rag-a-muffin evolved while mostly covering the costs involved. A “how to build article” would be another story on its own.

I have been marketing plans to home-builders now for a few years. During this time my main business was in legal ultra-light replicas of famous homebuilts such as the Air Camper, Pitts, Heath Parasol and Church Midwing. These aircraft, being replicas, sometimes caused problems in construction. For instance, the Air Camper has a rounded fuselage bottom which makes the landing gear more difficult to attach. The Heath replica has a landing gear braced with wire which necessitates adjusting after several landings. Now replicas are great and nostalgic and I wouldn’t give up any one of mine, but many builders are not concerned with replicating and would rather build for ease of construction. Along with that, the next concern I have observed is cost and availability to purchase building materials locally. This allows builders to pay for their project slowly and saves money on ship ping charges. All that I can say here is? read the remainder of this article, which will describe how my Rag-a-Muffin was paid for down to the last nut and bolt.

My first expenditure was $425.00. I visited a flightpark 60 miles away from my home which has many Phantom ultra-lights. Because of the Phantom’s aerobatic capability, many Phantom drivers remove their Kawasaki engine packages which were supplied by their manufacturer and replace them with engines with gearboxes. The reason is the belts would sometimes slip going through a loop. That certainly won’t be a problem for this design. I have owned eight Kawasaki engine packages and have only had a belt slip once before take off. Tightening remedied the problem. Also, I now have 400-plus hours behind Kawasaki engines.

I have purchased these engines for as low as $150 and as high as $750. I purchased the engine first because I knew this would be the biggest outlay of cash. My total for this engine was $430, including $5 for gas for the trip. What I received was a Kawasaki 440A 35 hp belt reduction and propeller along with all of the required parts, includin~ carburetor, muffler and fuel pump. The best supplier I know of for these engine is J-Bird in Kewaskum, Wisconsin (414/626-2611).

I generally have very few instruments cluttering my panel. I consider the minimum to be tachometer, EGT and wind gauge. The tachometer will make certain that there’s enough power to take off of my 400-foot grass field, and the exhaust gas temperature is used to tune the carburetor to prevent the engine from overheating. The wind gauge helps me stay above the stall speed of 26 mph. I ordered the tachometer and EGT which totaled $99, including shipping and handling. I built my own airspeed indicator and slip indicator from articles which I have seen in several magazines. I built these from leftover scraps of aluminum, tubing ball bearings and piano wire, so there was no cost and will not be counted in my total If I had to purchase materials, my guess would be approximately $15. To complete the powerplant package, I added a throttle lever, cable, gas tank and fuel line. For the throttle I used one a friend had given me. To build a similar one would cost about $5.00. To purchase one would cost $35. The gas tank, fuel line and bicycle cable was purchased at a local hardware store and totaled $1 1.43.

To get started on the airframe requires wood. I visited Carter Lumber Comp. which is just an ordinary house builders supply store. I purposefully went somewhere that I hadn’t shopped at previously. I asked to see their molding grade or clear Northern White Pine or Spruce. I was shown wood standing vertically in two bays. One contained I X 2’s, while the other contained 1 x 4’s in 8 to 16 foot lengths. Since these are actually only 3/4 inch thick I knew that only a table saw would be required to cut the 3/4 x 3/4 longerons and spar caps. I explained my intentions to build a flying machine and asked if I could take the time to inspect the wood, with the promise that I would leave everything as I found it. A go-ahead was given as long as I agreed to bring them a picture for their bulletin board. I spent the next hour and 45 minutes going through both bays inspecting the wood according to an article by the late Noel Becar that appeared in the March 1995 issue of EXPERIMENTER.

I came away with 16 boards at least 12-feet long at a cost of $1.10 and $1.70 per foot. The wood had a few random knots and was the clearest and tightest grain of the bunch. Total cost was $282.24. This is enough for the complete project.

Next on the list is plywood. A complete plywood list is one sheet of 1 /4’s; 7 sheets of 1/8 and 1/6’s. All is Finland or Baltic birch. Sheet size is 2-1/2 feet x 5 feet This can be shipped by UPS and weighed 68 pounds. This saves any trucking charge. Cost was $225.00 plus shipping which totaled $235.50. You can purchase this from your favorite supplier. Plywood suppliers are listed in the Yellow Pages under specialty woods.

A complete bill of materials is now available which simplifies purchasing metal and hardware and helps consolidate shipping charges. Since I did not have this at the beginning of the project I spent slightly more on four shipments, but all metal and hardware can be purchase from two companies – Alexander Aeroplane and TEAM Inc. The U-channel required to make the brackets and flight control hinges are purchased from TEAM. The remaining materials includes 6061 strut tubes, axles, cabanes, cable, thimbles, nicropresses, 4130 strap, nuts and bolts, pulleys, glue, etc., and all can be purchased from Alexander Aeroplane. Total cost of metal and hardware plus shipping was $305.92.

By the way, all brackets and fittings are a cut, drill and fit operation. If you can operate a hack saw and a hand drill, you can build all metals items required to complete the aircraft. There is no welding at all unless you need to mount your muffler in a different way than it was originally installed. I had to have the exhaust manifold reversed, which cost me $10 at a local muffler shop.

Seat belts were purchased at the local auto salvage. I got a set out of a new pickup with only 8500 miles on it for $15. On the way home I visited the local county airport to see if anybody had changed tires recently, and they had. I obtained a pair of 6 x 6 McGreagors just for the asking because they were only going to use them to put at the tiedowns in the grass in order to keep lawn mowers from running over the ropes. The tires were worn beyond limits for certified aircraft, but had no cuts. Thcey arc 6ply tires and ultralights normally use 2ply so there was enough tread to last a lifetime on an ultralight. I ordered a set of rims and tubes from Northern (I-800-533-5545) and had them delivered for $54.47.

To finish up the landing gear I needed a tailwheel. A stop by Grainger (1-800-225-5994) discovered the same identical castor as supplied by Loehle Aviation for use on their P-51 and Sport Parasol. The part number is 4×951, cost $14.39.

If vou have been keeping close track, you know that all that is left to be purchase are the finishing supplies. Another order was put in to Fisher Flying nProducts for 35 yards of fabric and cement, which was shipped for $139.50. There’s been lots of debates about the best way to finish an aircraft. Most people will use what they are comfortable with. Fisher uses black latex as a base, then covers it with automobile paint. My process is to fill the fabric with the color I’m using as my finish coat. During a stop at Sherman Williams and I purchased one gallon of Eaglet Beige, one quart of Flowtrol conditioner, one pint of red acrylic enamel, one gallon of spar varnish, three brushes and acetone. Total cost was $58.67.

To protect the fabric from ultraviolet damage, I purchased a large bottle of “Son of a Gun” – you know, the same stuff you use to protect your classic car’s dash. Cost was $8.87. I have used this system with great results on nine ultra-lights and recommend it for low cost and saving weight. As a side note, this system generally only adds 8 to 12 Ibs. for the entire system. The finish isn’t show quality, but it wasn’t meant to be; remember, it’s a ragamuffin.

The only other cost other builders will incur in this project is the $70.00 (now only $54.00) for the plans which I now make available.

As far as strength is concerned, the Rag-a-muffin uses the tried and true Pratt truss and plywood gusset method of construction with absolutely nothing out of the ordinary. Any veteran home-builder can look at the plans and recognize that the basic structure goes way back. Model builders will also feel very comfortable because the building method is best described as a large scale model.

What is out of the ordinary is the fact that this aircraft cal1 be built day in and day out for as less than $2000 complete and ready to fly. I can foresee people customizing their ‘Muffins and driving the investment way up. Others will build one quickly just to have something to fly while they are building their dream machine. With such a low investment for a completed flying machine, it would be very hard to lose money, and most people should even be paid back for their time involved in building.

Throughout my involvement with ul-tralight aviation I have met people just like me who have to save for weeks just to purchase a set of plans. I believe, like many others do, that if aviation is going to survive, it must be accessible to everyone. I believe the Rag-a-muffin or Ragwing Para-sol (for lack of a better name) are a step in the right direction. I know they will not suit everyone because some people just don’t like parasols, but, hey, give me time, I’m working on that problem, too.

For more information, detailed plans on the aircraft, covering system or engines, Please feel free to contact me at:

RagWing Aero
1705 Trail Rd.
Belton, SC 29627
Phone/Fax (864) 338-6092
E-mail RagWingMan@aol.com
Note: address updated
Please call anytime. The design has been flown for over 100 trouble-free hours, with four diffrent engines tested, including a 1/2 VW. A video is also available ($15) showing the plane being weighed and flown off my 400-foot grass strip.

Cost Breakdown
Engine, reduction and
propeller (used)…………… 430.00
Engine Instuments (new)……… 99.00
Gas tank, fuel line and
throttle cable …………….. 11.43
Northern White Pine ……….. 282.24
Aircraft Plywood ………….. 235.50
All metal and hardware ………305.92
Muffler welding ……………. 10.00
Seat belts ………………… 15.00
Rims and inner tubes ……….. 54.47
Tailwheel castor …………… 14.39
Fabric and cement …………. 139.50
Paint and Supplies …………. 58.67
Fabric Protection …………… 8.87
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Total cost 1664.99