This is how I build an ultralight powered parachute airframe
First I bought a powered parachutes and took lessons and learned to fly then I became an instructor and flew and/or owned most of the major models.
Then the FAA tightened up the regulations and changed the rules for aircraft that weighed over 254 lbs. So I decided to try to build my machine to be light enough to fly in the ultralight classification. This would avoid the license, inspections and other regulations.
Building anything is easy when you have the tools and material. The really difficult part is the design and planning. We all know that most major industries spend billions on research and development. I had to innovate so I built over a dozen airframes out of wire to a scale where one inch would equal 1 foot on the final design.
Here are a few of those scale models that were still in one piece
Even after building several scale models I built a full model out of cheap pvc pipe. Even though it was difficult to bend the pvc it gave me a "real size" model so I could see how the pilot would sit, enter and exit. And I could get a better idea of the shape and general "look."
At some point I eventually had to select the material. I wanted to be totally sure that the material would be strong enough so I did a stress test where I suspended 2 feet and hooked it in the middle and added weight till it failed. It took about 900 lbs to bend and it still didn't snap.
I purchased the material but in 20 ft links I had to innovate and find a way to haul it to the shop. I tied under my pickup at the front.
Then I removed the spare tire and used the cable that pulls it up to lift the material at the rear. NOTE... do NOT pull it tight against the rear axel. The rear axel will move up and down on the springs when you drive. LEAVE SPACE!
Here is a look at the basic raw material. The 4 pieces on the side are cheap rails for chain link fence I picked up at Lowes for about $7 each. They were used for making test bends without risking mistakes with the expensive stuff.
I weighed the raw material to see if I could build the frame and keep it under 100 lbs. Note: If you can't keep the basic frame under 100 lbs (and have it strong and safe) your finished frame be WAY overweight when you add tires, axels, steering - foot and ground, seat, etc. The Rotax 503 with muffler and engine mounts will weigh 100 lbs. You have 55 lbs for all the necessities including chute, risers, fuel tank. It's a challenge to make the weight - and have a safe strong machine.
I took my material to a company that had the equipment to professionally roll the prop guard and the frontal protection bars (and other pieces.) They are supposed to be professional but it looks like one of the workers has rolled his own although he hasn't light up and inhaled... yet.
More rolling... note.. if you want someone who can do it right... look for a shop that is so junky and cluttered you can't walk around. These guys roll about 80% of the steel that is used in Mobile Alabama... and a LOT of ships are built in the area that used rolled still for internal support.
I assembled the basic frame in my barn and strapped the joints together so I could do some testing/verification before final assembly.
Not only did I verify the balance of the chute attachment points but I used a 120 lb anvil to check the ground balance between the pilot and engine. If the rear wheels are too far forward the front of the machine would "pull a wheely" when the pilot gets out.
Time to load it up and take it to the shop where there are thousands of dollars worth of real tools for coping, welding, bending, grinding, drilling and fabricating all the parts needed to get off the ground.
I used sleeves and welded after using eye bolts internally to pull the joints together
Mount engine and chute
Just enjoy flying
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