2017-10-28_01-40-17 by jon newsom, on Flickr
2017-10-28_01-39-36 by jon newsom, on Flickr
2017-10-28_01-38-19 by jon newsom, on Flickr
That looks like it might be a problem...Snake Man wrote:I always wondered how they expected the pilot to be able to bail out of that thing without being turned in to hamburger !!
normandy wrote:"There was no reaction torque to cause a counter rotation of the fuselage, since the rotor blades were driven at their tips by the ramjets. Fuel was carried in the fuselage tanks, and was piped through the center support ring and along the rotors to the jets." From Wikipedia.
I think you got something there Axis.
The spinning contraption is still connected to the fuselage in some way. It would have to be assembled around some kind of shaft in the fuselage. "Every action has a reaction". And how do you get fuel to the moving engines out on the tips unless the fuel tanks spun with them? The fuel lines have to go wherever the engines go and have to eventually attach to fuel tanks. The fuel tanks and fuel lines had to be in the center of the spinning contraption or in the blades themselves and the tanks and lines would have to be able to move with the blades at that high speed spin. Same with any oil or hydraulics. Even then, wouldn't the the extreme G Forces make it difficult to control pumping of fluids? How would you have any lines run for gauges for the engines, temperature, etc. ? Those big blades and the engines would be a huge drag factor to forward motion too. I can't even imagine the stress those heavy engines on the tips would be. Had they solved any of this or was this all just fantasy? This is what happens when you hang around pilots and mechanics. 
I am no expert but from what I have read about the mechanical soundness it seems to be a workable design. Very smooth like a rotary engine of Mazda. The main thing I think that would have been a problem is if one of the Jets started to produce more or less thrust it would become unbalanced. There are control surfaces in the back, four of them that could be used to control trajectory but I have no idea how well any of it would actually work. The so-called green stuff is the Hydro span it hasn't been molded yet I'll do it after the lippisch is done. Also I believe there were fuel lines in the wings but were fed using a pressurized gasket system. It may have had some of the same issues that are rotary engine has with gaskets having to be replaced if warm-up times are not provided and any little gasket problem could cause a catastrophic failure. If nothing less it's fun to look at and I think of it as sort of like concept art, a lot of the 1946 luftwaffe stuff is pretty far out.Axis Nightmare wrote:I don't see anything to counter the incredible torque there would have been. It looks like a Chinese fireworks spinning whirley gig. You'd need counter rotating devices at best. Wouldn't it be like a helicopter with no tail rotor? What am I missing here?
Thanks!!pvanroy wrote:Actually, no torque is transferred to the fuselage: the rotor is being driven by the ramjets at the tip, and not from an engine mounted in the fuselage; hence, the whole setup just rotates around the fuselage, without transferring any torque.
This is actually one of the reasons why tip jets have been used in many experimental helicopter designs: this setup requires no tail rotor, as there is no torque to counteract. Several experimental helicopters have been flown successfully using tip jets, e.g. the Doblhoff WNF 342, Fairey Rotodyne and Jet Gyrodyne, to name just a few. Rotors powered by ramjets at the tips were tested in the Mil V-7, Hiller YH-32 and NHI H-3; the XH-26 even used pulsejets mounted at the rotor tips. So, technically, this is perfectly feasible, and it is possible to get fuel to the engines at the tips.
The Triebflügel design had reached a fairly advanced stage at the end of the war, with wind tunnel models being tested in the LFA wind tunnel in Brunswick at speeds up to 0.9 M. The main issue with this machine would have been transitioning from vertical to horizontal flight and back, and landing: these problems are common to any coleopter design (just look at the difficulties encountered by the Convair XFY-1, Lockheed XFV-1 and SNECMA Coléoptère); however, especially landing would have been particularly hair-raising in the Triebflügel, given that the rotating wings would have largely blocked the pilot's already limited view of the ground... Escape in emergency situations wouldn't have been as problematic as it may seem, considering that the craft would likely have been equipped with an ejector seat.
You corrected my assumptions on torque. This is the kind of expertise I was hoping to hear. Feasible yet not practical? Technology can overcome a lot but it would have had to be very complex. Look how long the Osprey was in development. Without a tilt feature and computer stabilization, the landing would have been a huge challenge not to mention what you pointed out as landing backwards and nearly blind. Would certainly have been a formidable and frightening weapon to contend with. Great Stuff!Jnewboy wrote:The mazda engine reference is just an anology, no fuel lines, internal fuel tanks are just on the inside of the wing in the fuselage and are turning with the wings. Here is some diagrams and a website with a lot of technical stuff on how to do it. Focke-Wulf designs were very advanced and a lot of thought actually went into this thing.
http://test.fiddlersgreen.net/models/ai ... lugel.html
Yes! It's a very long and brutal process financially and time-wise. But it does produce an amazing result once you work out all the quirks. The big problem now I face is that the interest in 1/18 scale is so low that I figure I will be footing the majority of the cost of producing most of the airplanes I would want. The sales will help some but it is hundreds and hundreds and hundreds over month after month after month of hydro span and a lot of silicon which is not cheap. Right now as I speak I'm getting ready to auction off a custom I made and just to be able to afford the resin and the silicone to finish the lippisch orders.normandy wrote:"The so-called green stuff is the Hydro span it hasn't been molded yet"
Ah, ok Hydro span to the scale desired, then a mold made of that and then a 1:18 piece...got it.
Very cool concept.
