Larry's geared turbofan jet engine.

The free turbine turns 60K RPM. The planetary gears reduce it to 14K RPM.

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Geared-fan technology is being further developed and refined by major manufactures like Pratt & Whitney - I even got an email from a member of the team who said my page here is hanging on the wall in the lab and everyone gets a kick out of it.

Where am I going to find a 14 (or 15 or 16) inch diameter fan that can turn 14,000 RPM? Where? Ha! Here's one on eBay! Oh no! Someone made a wall clock out of it! Argh! Rats --- I would have bought it anyway EXCEPT the thing was bid up to over $250.00!!! What do you bet the parts came as a result of a $601 Million contract GE won with the USAF to upgrade 1,202 GE J85 (developed 40 years ago) turbojet engines in the T-38 Talon supersonic jet trainers. with a new improved spooled compressor rotor and stator? Who gets the old parts? I want some! --- then I'm sure most people would rather see the parts made into stupid clocks instead of going to people like me! GE said (in a TV ad) they wish they could have helped Orvil & Wilbur, ha, they won't even talk to me let alone sell me they surplus parts - at any price! What's that about? I would like 300 pounds of static thrust but would settle for 200. Hey, anything to sound cool. My turbine engine is producting only about 50-60 HP, I think, even though the tag says 86HP! I'm getting 300 pounds of thrust now with a 68" 3 bladed prop, and now 310 pounds with a new 72" 3 blade prop (IVO 372), nice! But I'd rather have 500 pounds so I could go 100% vertical. There are new engines being developed for new little business jets that have fans just like what I need. Like the Eclipse 500 that will cost only $1,000,000.00. It has two little fanjet engines. The fan is just the right size - about 14 inch diameter. I've figured out that NO ONE is going to help me. I will have to do it myself. I'd have paid way more than $250 for the fan if it wasn't demilled and if it had a hub instead of a clock. My 20-to-1 gear box outputs 3,000 rpm but all I have to do is remove one gear and it will do 14,000 rpm. This is my spare engine. I assembled it from boxes of parts and flew it a few times before changing over to the professionally assembled (and wired) one on the plane now. We tore this one down to check the bearings - and all looks well. I'm modifying it a lot to reduce weight and simplify the fuel and throttle system. I'm thinking a 14 inch is a good diameter because turning at 14,000 rpm it will have a tip velocity of about 1,000 fps which is about supersonic. The number 7 seems to like me. I get 7 miles to the gallon of Jet-A, and I burn 7 gallons per hour. So a radius of 7 inches seems to be just dandy to me. I read somewhere that having a stator would be good. I found a couple on eBay for $15 each. They are 15 inches across -- just right. The fan will need lots of blades, maybe 100 or more?: These blades are 0.9 inches wide and 2.7 inches long. They have a nice twist and weigh 0.05 pounds each. I found the formula for centripetal force on the internet: Fc = (mass * velocity **2) / radius. So if I did my arithmatic right, the blades will "weigh" about 50,000 times as much? These cost me $1.00 each on eBay. I think I have about 120 or more, I hope enough. I don't know what the blades are from. Here's one with some numbers on it. It would be very cool to find a hub that holds these. I found this hub here on eBay for $20 It's the right diameter but the wrong slots. AND it's what they call "de-Milled" or something like that. They actually destroy it by cutting it so no one can use it for it's intended purpose. (thanks a lot guys!) So once again I have to make it myself - reinventing wheels is not helping. A blade weighs 1/20th of a pound standing still. But when it's being pulled around in a 7 inch radius circle at 600 miles per hour, it will pull away from the center with a centripetal force 50,000 times more, which is 2,500 pounds per blade! So I need to make a machine that will pull that much so I can test the hub I make and the materials I use. In this photo is a 1 inch thick chunk of 6061 aluminum which I drilled some holes the blade fits into. Next I need to see if it will hold. Here is the engine I've been flying as a turbo-PROP. I placed the large round part on there to get an idea of what it may look like with a fan. It will be a pusher turbofan. And I'll probably need a "duct" for the fan. On the left is the oil tank and oil cooler ($22 in the auto parts store, new!) It starts easy, runs real smooth, and sounds totally awesome.     One last photo of the engine on the plane. On the right you can see a bit of the empenague. (sp?) oops thanks Josh, it's empennage. It's French for "like tail feathers on an arrow". I notice that Williams International has designed an engine with a 14 inch FAN for the new Eclipse 500 business jet but lost the deal to Pratt & Whitney's larger engine. They were very nice to me and said they will continue to develope the FJ22 engine technology, however they cannot help me because of "litigation issues related to experimental aircraft" and other things. GE blew me off with a form letter to all the masses "who come seeking funds, technical advice and materials to aid in their personal inventions." and went on to tell me that my GE shares would go down in value if they "were to acquiesce, " by helping me! Hmmm, they spent how much money running TV ads saying how they wish they could have helped out the Wright Brothers, ha! I think I'll sell my shares in GE. They don't realize that I would be helping them way more than they would be helping me. Ask anyone who helps others. The helper/teacher often learns far more than the student, helpee. Too bad. GE stock is $31. Screw GE! I'm selling all my shares tomorrow (1-5-2004) and will buy BA (Boeing) at $42. Boeing it a real aircraft company - and they bought my old employeer McDonnell Douglas. I wonder if they would sell me some of the scrap they toss in the dumpster? What about Williams International? Or Pratt & Whitey? NOTICE: (update 11/2006 - 2 years later) GE stock is up from $31 to $35, but the Boeing I bought at $42 is now $86 !!!MORE THAN DOUBLE!!!!!!!! --- take a lesson! I interacted with them and figured out with just one email that GE sucks! (I should dig it out and publish it here, like anyone at GE would care, ha,) It was also easy to see that BA is cool. Investing is simple! I was thinking for awhile that if I knew someone in high places (you know, like maybe a congressman or the director of the PTO) that they could help me with the political problems with all this, but alas, NO, didn't happen! ---- everyone says they would have liked to help Orville and Wilbur but at the time - no one did, and it seems that after 100 years nothing has changed. 6-Jan-04: My trip to pick up turbine engine part with Jack Rogan - can't be worse than BarneyCam, can it? IPO: Sunday, 4-January-2004 My home page. See my other crazy projects. About 2000 page views from Jan04 to Jan05, wow, not much considering all of Pfranc.com has over 2600 visitors and over 7500 page views PER DAY! Oh maybe I forgot to add a link? In addition to everyone mentioned above, I want to thank: my girlfriend for putting up with me, google for information, eBay for parts, ----, -----, ----, and many others who have actually helped.

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