Gargamel

It can get blisteringly hot. I know of of podcaster for a well known woodworking podcast who was using cheap styrofoam cups to mix stuff in. He mixed up some epoxy and used what he needed, and let the rest harden up in the cup, as you do for extra you have no use for. The heat from the reaction actually melted the cup and caught it on fire. Granted, there may have been some other chemical reactions occurring, but I know first hand that epoxy gets very hot when setting up. I've done large pours of epoxy for Hulls on RC racing boats, and those suckers stay hot for a couple days (the 6-7 pounds of lead shot in them tends to hold in the heat too). It shouldn't get hot enough to deform PLA/ABS, so using a 3d printed mold should be ok. Using plastic as a positive to create a lost wax mold would work, but I have two main issue with it. If you have any larger sections in the design that taper down on both ends, getting wax mold out of the plastic one will be an issue. And for similar reasons, it will be very hard to verify that the ID's of the final product are to spec. There's a bunch of tricks you can try, check the interwebs for a variety of them.

My main issue with using wax for an epoxy mold is that epoxy is exothermic. I don't know what tolerances you are building this engine too, but epoxy under normal conditions, will usually heat up enough to melt or at least deform wax. And this will happen while the epoxy is still fluid enough to be affected by the wax deforming. A lost wax casting is usually a good method for casting, but if you have very tight tolerances, you might want to triple check the product before firing it up.

One of the coolest aspects I've seen in the forums is watching the younglings grow up. I'm old, middle aged, cranky, and pretty set in my ways. But it's really cool when I can see a new player, mid teens or so, discover the game. And then over time, we get to see the maturity come along just by reading the inane posts we all write. Not only do things like grammar and syntax improve, but the way they have learned to look at problems differently, quite often a skill taught by playing this game. Then seeing some of them fall in love with aerospace so much, they are attempting to make a career of it. And even if they don't, the passion for science and engineering this game invokes in people is a wonderful change to see happen.

Alternate Idea. Use the 3d printed part to act as mold for the epoxy. I'm not familiar with that particular epoxy, but a lot of them can be thinned with Denatured Alcohol to make them more viscous (less viscous? Runnier). Print a 'negative' mold of the engine you want, pour in the epoxy, add steel wire as mini re-bar if needed. Then you can burn out the plastic, or use a water soluble filament and just dissolve the mold. This will give you the material you need, in the exact shape you want. I doubt you can make a breakable mold while keeping the ID's as you want, so burnable/dissolvable may be your best route. This will give the exact wall thicknesses and shape you desire at each location. Still uses 3d printing and your epoxy. Since the plastic was just a form for the epoxy anyways, this will save you mass and size, and extend your run time.

You do understand how most 3d printers work right? They heat plastic filament till it almost starts to melt. Often just slightly hotter than boiling point, sometimes more. Pulse jets build up a LOT of heat. You're going to need some pretty serious insulation material to keep the plastic from melting. And then there's getting the material inside. I don't know if your going for a straight or U shaped pulse jet, but either way, it's going to be pretty difficult get a perfectly even coating of whatever this material is, inside a pre-printed tube. Especially if it's curved. Your best bet is to just get a Steel or Ti pipe. A thick wall Aluminum pipe would probably work well too, as long as you kept the duty cycles low. Unless you're going with a sintered metal printer, there are some thing's that 3-d printer excel at, making combustion chambers is not one of them. I have my own printer and use it all the time, and this is not a project I would be using it for. I'm a machinist, woodworker, welder, and maker in general. So I have a lot of tools on my skill set I can tap for a project like this. So my point of view might be slightly different than yours. But with that in mind, what's your budget for this project?

That's what google pulls up for me too.... I just had to laugh at that...

Or at least a SPH pic with some details. -Bienvenue. Commencez par poster votre fichier de métier afin que les gens puissent examiner le métier spécifique. -Ou au moins une photo SPH avec quelques détails. Now I'm really curious about that translation.....

I'm thinking from a historic point of view, they only ever carried one flag I believe. Now the mechanism to do exactly what you want is sorta already in the KIS mod, I don't know if there is a flag object available, but if I were to do this, I would want to physically move all 9 or so flags to the kerbal, and then have it take from that inventory. But I can imagine a lot of good uses for this, like setting up race courses around the KSC.

This is what I do, but make sure they aren't centered on the COM. I had an early prototype that was very very stable, but sideways. Make sure the trailing shield is farther from the COM than the leading one.

Ehhhhh.... I dunno.... Sorta strikes me as unrealistic... but we are talking about a game about little green men, so.... I think this would be completely acceptable as a mod, but probably not a stock feature.

I wonder if somewhere along the line, an engineer with a touch of nostalgia, made this a joke. I think I would would double check the processor I was buying if it was labelled 8086. EDIT: Hmm interesting. I was kinda right: https://en.wikipedia.org/wiki/Intel_8086

Even better.

I dunno, don't use them, I can deal with the pinwheel of near death, as I use stock chutes and atmo. I think there a few mods, in addition to what LGG mentioned.

We just recently had an in depth thread about bullroarers.

Wait.... how do you zoom?? How are you even playing the game without a mousewheel??? The VAB/SPH would be a huge pain, almost unplayable.

LESs are designed to be Zero/Zero systems. They are designed for the wort case scenario, which is sitting on the pad. Any other scenario becomes "It's not optimal, but it works" with the design. At some early point in a launch, the LES becomes less effective than an upper stage engine firing off, or even an ATO, at which point the LES is jettisoned. LES are not designed to be adjustable. There are mods out there that have tweaked the LES to be less pinwheely, though. All manned vessels have some version of a LES in my game. I do use a random failure mod though, so that is why. Some of my 40 man space buses do require some tricky designs to get a usable LSS though. The stock one doesn't even budge a 40 ton capsule.

On the flip side, the V-1's pulse jet engine was so loud, it could be heard coming from 10 miles away. It was only when it reached it's target did early models cut the engine (unintentionally) after starting their dive. The sudden silence indicated a buzz bomb was about to explode.

I know they have used props for timers, and that was the only thing I could think of. The detonator answer is the correct one, I could only remember the timer one.

That's a pretty difficult picture to diagnose, given the angle. A better one would be from the SPH, a side view with the COM and COL icons lit up. But basically, you should put your rear landing gear a bit behind the COM, so it acts like a fulcrum when you pull back to take off. But you have played with that some already. My only real suggestion would be to remove one of the tanks some of the materials bays and reduce the overall weight of the plane. Other's should have better ones. Or if you do require that much range and if you need the chutes to land , add some more chutes.

While it's really no skin off my back, I don't think they should at all. I guess it's one of the cool things in the game, that you have to get a kerbal close enough to it to read it. Check your persistence file, you should be able to find it and edit it there. Make a backup first.

Along with @p1t1o's answer, some bombs would have a little propeller on the nose. This would spin in the airflow, driving a clock mechanism, since it was delivered from a known altitude, the time to the ground was also known, and it could be set to detonate some altitude above the ground. That may have also been a source of the noise.

I've been playing for 5 years and I still have that question. Thanks for that link.

Which is really unsuitable for a ship of this design. Yes, you can use it, it will work, but it won't last that long. I'm a woodworker, not a wooden ship builder (I do build CF and plastic hulled boats though), so there may be processes that make pine usable, but there are many other hard woods available (pine is a soft wood) that are far more suitable for ship building. But they cost more, and will drive up the price.

I think if you answer no to this, then that logic might be able to extend to the Lunar Module Pilots of the Apollo missions. Harrison "Jack" Schmidt of Apollo 17, was a geologist by trade, not a pilot. And since I would have to vehemently disagree with that logic then, I would say, Yes, mission specialists are astronauts.