Pulsejet Powered Paper Cardstock Airplane Project
 

Just finished hooking the fuel lines up. Major project I've been working on. thought some here might like to see it.

Mike

RC or CL?

Looks like pushrods from servos connected to elevons on each wing.
This thing will be a handful as pulse-jets are unthrottleable.
I have flown some incredibly 'squirrely' R/C aircraft when I was basically the 'test pilot' for my R/C club, and this is NOT one I would like to be at the sticks for.

Nice build, cool idea, I guess that little engine must be pretty lite. Look forward to some flight videos.

WEAR HEARING PROTECTION (shooters' 'earmuffs' or ear plugs)! I echo GH's observation that your model will be a handful to fly. Flying wings fly very fast, and the lack of throttling capability will make flying it very exciting. Also:

In the late 1980s, I wrote to the AMA (Academy of Model Aeronautics) regarding scale data sources (or plans that could be adapted) for a R/C scale Horten Ho 229 (later Gotha Go 229) jet flying wing project, which would have used two Dyna-Jet pulsejet engines. I received a letter from the AMA that begged me to *not* use pulsejets, suggesting ducted fans instead (today, of course, real model turbojet engines are available). In addition:

Besides the obvious risk of fire in the event of a crash (since model pulsejets glow red-hot and use gasoline for fuel), the AMA feared that the ear-shattering noise would make the flying site's owner--and the neighbors, if any--disinclined to allow any other model airplane flying at the site. (C/L [Control Line] pulsejet model planes -are- flown at AMA-sanctioned events, but special arrangements are made to mitigate the noise and the fire risk. The AMA isn't against pulsejet models, but they *do* encourage flyers of such models to do so in the safest, least bothersome ways. They suggest that C/L is the safest type of control to use.) Now:

This does *not* mean that safe, docile R/C pulsejet models don't exist, but those that have been flown had/have higher wing loadings and have proportions more like those of fast, aerobatic full-size sailplanes (like the Schweizer 1-26). A model flying wing with proportions like those of the Horten Ho I or Ho III sailplanes would be equivalent.

Like.

Agree about the "hand full" to fly. Using a fuel tank that is three times smaller than what is recommended. Will do some engine run tests on varying amounts of fuel, to time fuel burn, before the first flight.

The thrust is greater than the model weighs, filling the fuel tank to 100% will be 2-ounces more than the thrust available.

In a big way I'm hoping the advertised thrust is exaggerated!

Plan is to get it to altitude, should almost be able to vertical, fuel exhausts and then glide back.

Level flight is going to be an issue. I've seen how fast pulsejets fly! Plenty of youtube videos from across the sea.

At first was going to use a catapult to launch, because it is so light, designing a drop away "cart" to actually takeoff (very similar to the ME163).

Did some weight testing during construction. 15lb weights with structure supported at the wing tips, then used 30lbs to test the center section buy moving the wingtip supports closer to the center frame. No issues, except for a couple of trailing edge ribs popping loose from the trailing edge. Now that the wings are covered that won't happen.

Used fiberglass layup to make the spars. Metal heat shield to protect the paper. That will be part of the ground testing, to verify it works.

Bought some stuff called "No Burn". Supposed to protect wood and paper products from catching on fire. Sprayed it on a test piece to see if the ink would run and paper warp, worked great. In a few minutes taking it out side and hittin it with a propane torch to see how fast it burns!

If everything goes right, should have test results by tomorrow on engine burn times and fuel consumption.

Mike

Having an R/C model powered by a Pulse-jet that has a more than 1:1 thrust to weight ratio is no-joke INSANE. I have several R/C planes that have better than 1:1 thrust/weight, but they ALL have throttles.
Not to be a wet-blanket, but I GOTTA say this is an accident waiting to happen. Have a good "Fire Crew"
I think you are underestimating what a "Hand-ful" this thing will be to 'fly'.
Have someone video the first flight. It WILL be spectacular, but not in a good way.

I agree. But I think a flight profile like that of the Me 163 Komet rocket interceptor (which was like that of an X-1, X-2, or X-15 air-launched altitude run, but done from ground level) could be flown safely, *if* the model has sufficient stability margin. In fact, not long after Chuck Yeager's October 14, 1947 supersonic flight, the X-1 was once flown from a *ground* takeoff in such an Me 163-type "zoom" flight profile (with Yeager again at the controls) to above 40,000 feet, in order to establish an FAI official supersonic flight, because their rules didn't recognize air-launches. But flying such a model in horizontal flight and conducting maneuvers and high-speed passes under pulsejet thrust? I wouldn't want to be very close...

A model this crazy might be easier to fly if flown with one of the so-called FPV (first person/cockpit view) video systems than traditional R/C.
Might be worth investigating before "going for broke" first flight.
I think it would be too hard to keep up with flying standard-style R/C.

The main danger with this project is not if, but WHEN it impacts the ground unintentionally, it IS going to start a fire.