Ol’ Musky Boi

Stock KSP currently gives us 3 ways of generating power (not including engines), fuel cells, solar panels, and RTGs. For most spacecraft this works fine, but If I'm trying to build large ion powered interplanetary ships or surface bases on Eeloo I really want something with a bit more oomph, and something to justify these giant radiator panels... Something along the lines of NASA's Kilopower reactor that is very expensive and produces large amounts of heat and power would be great. It could either consume ore or some sort of new resource like "Krakenite" that would have to be shipped to surface bases. I know that this sort of functionality is available with mods, but having them in stock would be nice. Just an idea, let me know what you think.

I'd love some slightly bigger monoprop engines, 1.25m and 1.875m would be good, that way we can have more accurate space shuttle OMS and won't have to lug around those massive LfOx tanks or clip together loads of smaller engines.

So last weekend I finished assembling Mr Whippy using the parts that I machined on the school lathe (that made the whole process a whole lot easier) - and I then attempted a test fire. I encountered a couple of problems, the first being that my assembly wasn't airtight around the pin valve (which you can see in this album), so leaked when I attempted to pierce the cartridge. Given that all of the gas escaped out of the front end of the rocket I narrowed down the leak to where the pin broke the seal, and I've attributed this failure to an incorrect o-ring size (I didn't have one that fitted snugly around the pin, so I used one that was much too large and didn't plug up the cartridge after piercing properly). The second problem was that my ignition system failed to melt the burst disc. I tried to use a firework sparkler that I slid through the nozzle and rested against the disc in the hopes that it would be hot enough to melt it, and this was supported by some testing I did outside of the rocket. However this didn't end up working, and I think this is because the contact time between the disc and the flames is so low and the exit diameter so small that no meaningful amount of heat can be transferred to the plastic. I will try to remedy this by widening the exit hole and possibly using some kind of pyrotechnic grain or slug in place of the sparkler, I was thinking nitrocellulose "flash paper" rolled up into a tube or some sort of gunpowder pellet, any other ideas there would be great. Failures are good for improvement, so I'm not discouraged by this and still hope to get something working by Christmas, but only time will tell ¯\_(ツ)_/¯

Hello all! Construction of my first prototype hybrid (named Mr. Whippy, because the N2O cartridges are used to make whipped cream) has begun! I had a friend come over today and give me a hand, and in about an hour and a half of work this is what we got done: https://imgur.com/a/MQGTK7R Unfortunately due to a lack of tools the parts ended up being quite crude and wonky, and they took forever to cut with a rusty hacksaw. We will see if we can get permission to use the school lathe to make production easier. Casting the wax was a little tricky, because paraffin shrinks as it cools. So we had to top it up several times to get a complete cylinder (we then twisted a drill bit into it to make a hole, but that ended up being quite wonky). Next time I'll probably put a rod or something in the actual mould so we can get it more consistent, and we might try more sophisticated grain shapes. (note: the nozzle dimensions changed since last time because I found a few errors in my calculations, the throat diameter is now 3mm and the exhaust diameter is 8.2mm based on 25 bar and 2000K chamber conditions - chamber temp was calculated with help from the book "Ignition!" and chamber pressure is just the half the pressure of the N2O cartridge). So some progress has been made, we hope to get a motor test fired before Christmas, winter isn't particularly harsh in the UK so that shouldn't be a problem.

That's nuts! I was almost certain it was modded! How long did that take you to make? With all that attention to detail and only 1FPS it must've taken an eternity!

The second variant will make a great cockpit/turret for WWII bomber replicas, I'm loving these new texture revamps!

Ok, this is nuts. I'm going to have a go at making one of these crazy things.

I'm using a straight approximation with an ~15° exit angle, it'll make manufacturing the nozzle easier. Thanks! I'm not the first to think of it, there are commercially available hybrid motors that also use N2O cartridges, like this. I took a few cues from their design, like the burst disc ignition system, but I'm using a fuel that'll be easier to cast into different grain types, and it doesn't look like they had a deleval nozzle on theirs either.

Correct me if I'm wrong, but whilst that would increase flow speed (according to Bernoulli's equation) doesn't that actually decrease mass flow rate? It seems a little counterintuitive that a smaller cooling volume should correspond to a higher rate of cooling. It's been a while, but I (think) I've finished the design equations for my hybrid motor. I would post my math here but I did it all on paper and it looks a mess , so I'll just give you the numbers I got. Specific impulse: 111s Total impulse: 9.625 N/s Thrust: 19.25 N Area at throat: 3.17mm^2 Area at exhaust: 9.47mm^2 These calculations were based on the assumption that: Chamber pressure: (20 bar - perhaps a little conservative) Combustion temperature: 1750K Burn time: 0.5 seconds (this allowed me to calculate mass flow rate, as I already knew the mass of my propellants) Here's the general design that I'll be following. The problem with using nitrous cartridges as an oxidiser is that the container must be physically pierced to allow the gas to escape. The system I came up with here uses a wing bolt which, when tightened, forces the cartridge into a sharp and airtight pin valve, but the gas is still prevented from escaping by a small plastic disc. Then, when it is time to light the motor, an electronic match can be used to melt the plastic burst disc in the injector, releasing the nitrous and igniting the engine in the process. I hope to begin building a prototype soonish, but I have my final exams coming up so I'm not sure how much time I will have for this project.

Good to see progress! I haven't been following this thread for very long, what is the purpose of the cooling rods? Is it to keep the cooling jacket centred?

Cool! Valved or valveless?

Nice work as always . I don't think regenerative cooling should be necessary unless you're planning on actually flying this engine, I'd stick with water cooling for the time being. On the subject of fuel flow - perhaps increasing the flow rate might solve some of the problems you've been having with combustion instability? It looks as if the pressure in the chamber is higher than the pressure of the fuel coming in, which prevents the fuel from flowing in at a constant rate, resulting in the inconsistent burn. Or at least, that's what it looks like to an un-qualified rocket enthusiast like me, I could be wrong. You're also right that a lot of the design calculations in the book aren't directly applicable to a hybrid engine, but I've found that this book makes quite a good additional reference, and covers a lot more areas than the former. As for my hybrid rocket, I've decided on a slightly different approach using these small canisters containing nitrous oxide (both a good oxidiser and a monopropellant) that are usually used to make whipped cream. This isn't a unique approach, and a quick google revealed that this has been successfully tried before by many in the model rocket community. I'm currently ordering parts to begin the design process, I will update when I've progressed further. (As an interesting side note, it is actually illegal to build solid rocket motors of any size here in the UK, so if I want to see something fly then hybrids are basically the only option. )

Wow, there's some really cool stuff going on in this thread! I'm impressed I've been thinking about building a paraffin / oxygen fuelled hybrid rocket engine for a while now, ever since I picked up a copy of "how to design build and test small liquid-fuel rocket engines". Paraffin wax and gaseous oxygen are very easy to obtain and safe to work with, so it seemed like they would make the best propellants. I'll need to do some experiments to measure things like combustion temperature etc before I can begin the design process though. Hopefully I'll get round to it at some point.

Thanks for the answers everyone! I've been looking around and I've decided that I'm probably going to go with a Thrustmaster T.16000M FFCS Hotas, I've seen a lot of good stuff about it online. It's about £110 for both the joystick and the throttle control, fairly decent for what you get. Looking forward to playing KSP with these

Yeah I didn't really expect too, but you never know these days wether or not someone will find your choice of OS offensive. People take it way too personally. Nice! I'll check it out.

Been thinking about getting a joystick for a while, mostly for KSP but probably for some other flight games as well. What do you guys use? And do you have any good recommendations? I'm probably willing to spend up to £200, and I play on a Mac (please don't crucify me). P.S: I've never owned a joystick before so it's all new to me.

I built one of these For a tip-jet monocopter, she's VERY maneuverable and pretty speedy to boot. Landing can be a little tricky, but possible and relatively easy once you figure it out. I've had great fun flying around the KSC with this. Here's the craft file: https://steamcommunity.com/sharedfiles/filedetails/?id=1506090709

Thanks! I really enjoy the challenge of building these sorts of contraptions in stock KSP. It's really incredible what you can do with the stock game, most other games don't have that kind of flexibility. I'm not quite happy with them yet so I haven't posted a craft file. I'm still experimenting with new ideas, but I hope to release the final products soon-ish.

Here's my latest experiment, an electric micro-copter with a juno for added speed. The bearing is incredibly smooth (I was inspired by this creation on KerbalX https://kerbalx.com/quitessa/Ultrasmooth-Microbearing) and doesn't have any stability issues, at low speeds manoeuvring is quick and responsive; with decent piloting skills you could probably get it to do precision landings on the VAB. When using the juno in horizontal flight you can get up to about 40m/s before losing control (dual rotors would probably fix this ). The whole craft weighs a little over two tonnes, but most of the weight comes from purely aesthetic parts and the prop is slightly overpowered as it is, so I could probably trim it down a bit. Overall, a success!

She flies OK if you're only doing short up and down hops, but like you said, angular momentum causes steering to be tricky. This is the biggest issue with this copter, if you try to make too many pitch or roll maneuvers then the bearing flexes and explodes. You could probably get around this by adding jet engines for forward flight but It still means no barrel rolls I think I might experiment with all-electric copters, since I've got much more experience with electric props than I do jet powered ones. The tail juno was just there for aesthetics, probably didn't help the stability much because it made the craft slightly rear-heavy, but it was only a prototype. Good luck on fixing your copters! I too understand the hardships of KSP withdrawal.

I decided to make a thread for the under-appreciated stock helicopter. Here's one I made earlier! Dubbed the Roton Mk1. It's a little wobbly, but for something that I threw together in about 10 minutes I'm pretty happy with it. (Edit: Lets just ignore the fact that the tail rotor is the wrong way round )

Steam link: https://steamcommunity.com/sharedfiles/filedetails/?id=1470890638&searchtext= So here it is, although my propeller powered version worked, it was not reliable. So I compromised and built a jet-powered version whilst I continue development of a stable turboprop. I was going to give up, but after seeing Stratzenblitz75 sending a stock helicarrier TO LAYTHE I had renewed hope. That version should be done in a week (I am a bit of a perfectionist...)

Thanks for the tips, I'll try redesigning the props with a more stable bearing, and see where it goes from there. If I can increase thrust significantly then maybe I could downgrade the engines, but I doubt it.

@HansonKerman Hey.

It means I laughed...