dhc6twinotter Posted October 15, 2011 Posted October 15, 2011 Hey all, So, this is just a small project I've had built for a while, and I thought I would post up some pictures. This is a 16 cylinder radial engine with variable pitch propeller. The crank is built using the standard half offset crank pieces that is common on all Technic engines. Each piston is connected to a standard Technic connecting rod. Opposing connecting rods are linked by a thin 1x7 liftarm. There are a total of 8 thin liftarms, with 4 per row of cylinders. The liftarms kinda flop around, but it works very well with no binding. I ran the whole setup during the entire BrickCon event, and everything worked flawlessly (although the motor started to whine at the end). The variable pitch mechanism is built without the use of a swash plate. Everything is done through gearing. The propeller hub is built like a shaft within a shaft. The outer shaft spins the prop assembly, and the inner shaft changes the blade pitch. Under normal conditions, both shafts are driven by the motor and spin at the same speed. However, when the hand crank on the side is turned, the speed of the inner shaft changes and the result is a change in blade pitch. The differential is the key to the whole system and allows the speed of the inner shaft to vary. I'm pretty happy with how it turned out. The only problem I have is the number of cylinders. To my knowledge, there was never a 16 cylinder radial engine built. Because of the spark plug firing order, most, if not all, radial engines were built with an odd number of cylinders per row. Radial engines were built with 3, 5, 7, or 9 cylinders per row. Two row engines, like mine, would have been 6, 14, or 18 cylinders. Then there are the engines that have more than 2 rows, like the Wasp Major with 4, or the giant Russian Zvezda radials with 6 or more rows. I think that covers most radial engines, but I'm sure there are exceptions as well as more obscure engines out there. Anyways, I just thought I'd show a little project I've been working on. I hope to build a plane to go with the engine some time. Sorry about the dark pictures. It was overcast the day I took them. Thanks for looking! Quote
DLuders Posted October 15, 2011 Posted October 15, 2011 (edited) I was fortunate to see this wonderful engine at Seattle's Brickcon 2011 convention two weeks ago. It's big -- 35 studs long X 35 studs wide! If this is ever put into a GIANT Lego Technic aircraft, it will be even more awesome! :thumbup: There was a CAR which had a 16-cylinder radial engine -- a 1935 Monaco Trossi: Edited October 15, 2011 by DLuders Quote
dhc6twinotter Posted October 15, 2011 Author Posted October 15, 2011 Thanks! That's interesting. I didn't know there were any real 16 cylinder radial engines around. But I guess that one makes sense since it is a 2 stroke engine instead of the more typical 4 stroke. I figured there was some obscure engine I was leaving out in my description. I actually haven't measured the size of this moc. The 35x35 dimensions I gave at BrickCon were just a guess for the sake of table space, and includes the width of the prop. It should be very close though. I'd like to put this engine in a Grumman Avenger, but I'd like to see if I can figure out how to make a more realistic 14 cylinder version. That might be more difficult than it's worth, and I may just stick with this design. Thanks! Quote
apemax Posted October 15, 2011 Posted October 15, 2011 What a brilliant radial engine. I would love to see the this beast in a aeroplane. Well done. :) Quote
Corweena Posted October 16, 2011 Posted October 16, 2011 wow! from an aviation enthusiast and aerospace engineering student, this is amazing! Quote
Zerobricks Posted October 16, 2011 Posted October 16, 2011 Love the variable pitch propeller, its really awesome! And the 16 cylinder engine configuration? Just massive! Quote
dhc6twinotter Posted October 16, 2011 Author Posted October 16, 2011 Thanks! I do plan on putting this in an airplane, but that will be a while from now. I have a few other mocs I'd like to build before I build a plane. We'll see though...I might change my mind. Love the variable pitch propeller, its really awesome! And the 16 cylinder engine configuration? Just massive! Thanks! It's not as big as your X24. I'll try to get a video up later today. My computer took a dump, so I'll have to see if I can borrow a different computer again. Quote
dhc6twinotter Posted October 16, 2011 Author Posted October 16, 2011 (edited) I just finished up a simple video: Edited October 16, 2011 by dhc6twinotter Quote
Burf2000 Posted October 17, 2011 Posted October 17, 2011 I have always fancied building one of them, did it take long? Very fine example I must say. Someone did a pneumatic one that was rather interesting Quote
timslegos Posted October 18, 2011 Posted October 18, 2011 Wow fantastic MOC!! Its amazing that you fit all of that and made it work! Nice video to. tim Quote
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