[Thread to discuss negative things in a very general way, just see where it goes y'know?]

Gearing up for a series of projects using raspberry pi to learn python among other things, and it seems like lately when Amazon says one day shipping, you won't so much get it in one day, more like you'll get it one day, maybe.

Starting to feel like I'm personally underwriting the specialty cable industry, and I haven't even started running basic projects yet

Scope creep, my old nemesis, we meet again.

[Thread to discuss negative things in a very general way, just see where it goes y'know?]

To err is human, to really f...oul things up, requires a computer

 

[Thread to discuss negative things in a very general way, just see where it goes y'know?]

I had a run in with "unifying receivers" from logitech, those are not ready for prime time, everything is fine,  until you have more than 1.

[Where is the parking brake for rover wheels?]

I can't seem to find a setting for persistent brakes, where is it?

[Thread to discuss negative things in a very general way, just see where it goes y'know?]

You ever have one of those days when you don't think that you could lose any more respect for humans, only to have them prove you wrong?

[Cooling a convert o tron, just how much do you need?]

Looks like I'll just be scrapping that whole idea, the setup is just a troll by the devs, they should just remove the parts, if they're gonna make it useless, they should just leave it out completely.

[Building outside the VAB?]

You can build them in chunks and assemble them in orbit.  You might try the aircraft hanger, but you can't assemble things in the parking lot as far as I know.

[Cooling a convert o tron, just how much do you need?]

Makes sense in a way, so scaling to the bigger convert o tron it is then.

[Cooling a convert o tron, just how much do you need?]

I've been trying to make a fuel depot on mun, (for the chuckle value) but I can't seem to cool a convert o tron jr, using 8 tons of cooling system hardware.

Is there some trick to what kind of cooling? placement? My "try really hard" version was 30 tons, half of that was thermal control systems, how do you keep the temperature stable? Is this just not possible under any circumstances?

 

[A question on the efficiency of a long burn]

The magic number is 1 fuel cell per 2 motors, and indeed looks 1337, I tested it with a 6.3 ton model, 6 burners, 3 fuel cells and a t-200 worth of fuel for the cells, it managed to burn a bit over a third of the xenon. (8103m/s starting tank, at 1.8m/s) This should not only scale pretty well, but "tree" pretty easily,  making detachable segments that stack  and thrust together. (no idea of how to maneuver such a thing, not that far along in the process, but it's an interesting question.) I guess I'll get some practice docking stuff playing with it.

[A question on the efficiency of a long burn]

I think a "branched tree" xenon mother ship still has legs, I made a somewhat practical 30 ton model with an "any direction" solar array. (the "bad" angle drains the batteries at 10/sec, which yields a 15 minute max burn, at 1.8m/s, 7km/s on-board.) As a munar tug boat, it's not a bad solution.

The solar array is a problem for scaling, for a mothership I might go with full on fuel cells and save myself the lift nightmares of a 15m radius, haven't tried that yet. (fuel cells are also bulky)

If I did a grand tour, it would be way scaled back from 1500 tons, and no kerbals to kill, but I want a munar mining facillity. (cooling a convert-o-tron, can it be done?)

In the most recent update (1.11.x) it seems a lot of mods are broken. (they did fix a bunch of stuff in the stock game)

[A question on the efficiency of a long burn]

Well, I've already sank my teeth into the problem,  I don't feel like letting go without a fight. (6 day burn, I suppose that mod allows warp during burn?) It takes about 2.5 hours to run a test at eloo (the sailboat I just tested had something like 25 gigantors, generating 4 per sec at "peak angle", so well less than 1/ps for each fully exposed gigantor at eloo.) Still, I'm a pretty clever lab rat, there's a couple things I haven't tried yet.

Still, I don't hold out any hope that this would scale to 1500 tons, and not in a form that would carry you beyond duna anyway. Meanwhile, a challenge is a challenge, how big can the xenon systems scale? and what does it do to counter the lack of sun at eloo in a not horrible fashion?  I don't really do kerballed missions, I fly into things too much, but it might be fun to setup a much smaller group of probes , dropping them off would still be quite a trick, even more so, because I do not fly with the least amount of elegance, the fuel would be monumental.  (my "super probe" could probably visit 4 maybe 5 planets, but not land anything, and not much science on board)

The peak power point for the xenon engines seems to be a 3 thruster system, at least for deep space. (the only configuration that can yield 1.8m/s with long range in the dark.)

Anyway, I guess I'm off to play with fuel cells for the moment, thanks for the tip on fusilages, I'll be playing with the nervs next.

[A question on the efficiency of a long burn]

I'm working at maybe 1/10th scale to the beast you're working on, but you've given me something to chew on, the rather flat response from the solar panels at eloo (and the 42 minute burn to get out to a test range) have put a crimp in my thrust budget, but that's only part of a grand tour, I'll have to spend a couple days cooking up some deviltry and testing it on a heavy ship.

[A question on the efficiency of a long burn]

Are you using regular fuel tanks and just scrapping the oxygen? (been up a while trying to get a large scale xenon setup running, the current one looks like a camping stove, working out a good multi-angle solar geometry is proving a little much, given that it needs to launch from ground, but it's easy mode, so it won't snap if I breathe on it, mostly it's a question of scaling, so I'm not trying to press the rest of the situation. Just seeing how far I can bend it before it breaks, so far 48 engines at 91 tons and something like half of that is just fuel in the tanks it can dispense to other ships. I'll see if I can drive by eloo with a better solar geometry)

[A question on the efficiency of a long burn]

9 hours ago, king of nowhere said:

if you mean physics warp while burning, then no. i had the persistent thrust mod installed, and the first project of this ship was with ions, and much smaller. unfortunately, something broke, and after multiple attempts at making it work, i had to shift to nuclear

Wait, you're using nerv's instead of xenon? Why dear and fluffy lord why? xenon is the only build I can stack 17km/s of usable thrust on a probe. (BTW, if you use tweakscale, it will cut the xenon thruster in half, 1Kn instead of 2Kn, making it totally useless)

I've had a good bit of playtime making long haul probes recently with xenon thrusters, one trick I can tell you is use the small radial xenon tanks instead of the stacking tanks, it greatly reduces the tankage weight factor, allowing far more Dv on the same fuel. The number 1 problem is balancing the electrical, followed closely by maximum acceleration. 

The "mission constraints" (arbitrary standards) required the craft to sustain a 10 minute burn time, have over 1m/s acceleration, and over 10km/s in the gas tank. I can do that with xenon all day, but I've never gotten even close to that trying to use nerv's. (that could be me failing to pick the right gas tanks, but the ships with nerv rockets couldn't ever beat a decent terrier design.)

This is an interesting question, as using either tech to it's utmost requires some level of design juggling.

[Building very heavy rockets]

Just for the giggle and snort value, 11 vectors strapped to the bottom of 2(ish) full size S4 tanks, at 620 tons gross vessel mass, has a TWR of 1.81, max acceleration of 17m/s, and 5168 ASL delta v. (raw tankage, no payload factor, but you get the idea)

 

Edit: Oopsie, wrong delta v number

[Building very heavy rockets]

2 hours ago, SunlitZelkova said:

I'm not sure if this was directed to me or not, but I will answer just in case.

The payload is the LK-700 (which includes the capsule, landing gear, TLI stage, and lunar crasher stage) replica for a Munar landing. Mass is 94 tons. I have tried the things people have suggested here but it doesn't want to fly, even with Mainsails.

I have also tried mounting it (LK-700) on different rockets (like my smaller design based on the UR-700) but it doesn't work.

Perhaps it is time to sacrifice accuracy and just build something regardless of design, so long as it can lift the LK-700?

Lifting 94 tons should be pretty easy as a project, but you are trying to make a working replica of a specific rocket if I'm not mistaken.

A seven pack of BFSRB's is enough to ssto that much, depending on how "bulky" the scaffolding is, but it might be a bit too bumpy a ride. (Not specifically familiar with LK-700)

For motors, there are only 2 that have maximum ASL thrust, the mammoth, and (yeah, don't laugh) the vector. Why the vector? because you can cluster it big time, and the mammoth is the highest single engine thrust in the game. (Neither allow for use in second stage as described, as there is no decoupling option.) You can squeeze 7 vectors onto an S3 gas can, with room for 11 on the S4's (9 is generally enough) It has the highest thrust potential per surface area taken in the game, and gets top marks for ISP ASL. I would say try those 2 before scrapping the design.

 

[Building very heavy rockets]

1 hour ago, king of nowhere said:

well, i do agree on a certain level, and i make a point of using some manual struts even if autostrutting would be more convenient.

however, i still use autostruts when it's necessary. mostly for docking large ships, as those tend to blow up after docking if you haven't autostrutted them. also, when i use large ships, to reduce part count; when you are using a 1000-part ship lag is a problem, my cpu can take all the help it can get. and in such big ships, the few quintals saved on struts won't make a difference anyway

This is a sandbox, you make whatever castles you like my man. 

I make satellites with rosettes of shrimp missiles to blow up other satellites, just because the mood strikes me to do it.

[Would like some help with the Sciencey basics]

At the risk of post flooding, I'll mention some stuff I use a lot, first, SRB's are soooo your friend, learning how to tune them will give you lots of cheap thrust, in fact SRB's are the cheapest thrust you can buy.

This comes with the price that you must set the throttle in vehicle assembly, and once lit, they burn until they are empty. Most of my first stage rockets are pure SRB, designed to burn to 70km altitude. (yeah, the first liquid fuel engine to light will already be in vacuum) Now look, this is not the most efficient way to burn, requiring delayed turning, over thrusting, and a pretty strange looking steering curve. However, it's MUCH cheaper than conventional first stage rockets, by about half, to as low as a quarter, with the right payload.

To put this into perspective, you can launch a mk-1 with 2 hammers (trashcans full of boom) and a flea, and get a vertical apoapsis of about 300km.

The recipe is a mk-1 capsule, 1 mk-16 parachute, (2 radial droge chutes if you have them, just to smooth out the ride), 3 td-12 decouplers, 2 rt-10 hammers, 1 rt-5 flea, and 18 basic fins. Capsule first, chute(s) on top, (throw a couple barometers and goo on it for the points if you like) td-12, flea (set to 40% thrust), 6 fins on the flea, td-12, rt-10 (set to 50% thrust), 6 fins at the bottom of the rt-10, td-12, rt-10 (set to 100%) 6 fins on the bottom. (yeah, that will actually fly straight, don't forget the fins, and I really don't recommend turns)

This is a big point to consider, because  the cost of your projects really matter, and saving money can be as important as conserving TWR, or more so. (as if there weren't enough points to consider)

I tend to focus on "lift per dollar" rather than "lift efficient" it's a different perspective to look at the question from. Not sure how helpful this might be to your specific goals or playstyle, but it is food for thought.

Second, if your rocket "wobbles" adding control rings will likely make it worse, add struts instead, add control rings when steering is too sluggish. (if I'm using a very long rocket, I'll use a girder segment  as a high point to attach the struts vertically, but if using struts between stages, keep it to 3 or 4 struts, too many, and you'll need a stack separator, or it won't let go.)

Third, always check your electric draw, and make sure you have enough batteries (and/or panels), no amount of fuel will save an out of control rocket with dead batteries. ( I've done this too many times not to mention it)

[Would like some help with the Sciencey basics]

One thing I did catch, was the fuel priority, you don't need fuel lines to crossfeed fuel,  radial decouplers can crossfeed fuel as well, so you can use that even in relatively early game designs, so I thought I would mention it.

[Would like some help with the Sciencey basics]

For my mun minor project, a 30t drilling and conversion station, I'm using 6 cub vernier engines (32Kn each), using the landing autopilot uses about 1000m/s of fuel (which is far better than I can do by hand) with a fuel payload of 1500m/s, this was not meant to return on the remaining gas, rather it needs to mine the difference, or just stay put.

The best I've managed flying by hand (mind you in like 0.91 or earlier, because I haven't played with manual mun descents in years) was about 3000m/s

The moral of this story is simple, manual landings that are good on gas take a excrementsload of practice.

[Building very heavy rockets]

37 minutes ago, Curveball Anders said:

You can't cheat in a single player game.

Unless you mean cheat on your own rules.

Something like that, clearly the devs put it there, so it's not outside the game boundaries, but then, starting your career with 5000 science points is also an option.  

I care more about building good rockets than manually flying everywhere, so I tend to be picky about the details, but I agree with the implication that there's no wrong way to play in a sandbox, other than perhaps throwing the sand at the other kids at the park.

[A question on the efficiency of a long burn]

The manuver planner starts a long burn just forward of prograde, and finishes a bit behind (you may need to flip the words) so for a 5 minute burn, you would start burning at 2:30 from Ap, and burn basically to  Ap +2:30 

Running a slightly retarded prograde, transitioning to a slightly advanced prograde seems to keep the Pe/new Ap  "still" (not sure what to call it, sorry) If you're flying manually, best to just go full prograde, and correct "longitude" if needed.

I like the little xenon motors, they are fun for long haul probes, but you have to think ahead for stuff going to eloo, you get about a third of the solar power that you get at kerbin. (which is very generous of the devs, BTW)

[Building very heavy rockets]

I can understand the attraction, especially for big multi-layer assemblies, but as a designer, I feel like it's a save weight easy button.

That being said, I got a pretty good run down on how they work, and I'll have to play with them a bit, apparently there's a weirdness to autostruts where it comes to docking ships, and the change in tension causing "kraken attacks",  sounds like a fun way to detonate an orbital base.

BTW, do any of you wreck stuff just for giggle and snort value?

[What is this "autostrut" of which you speak?]

I remember the strut drag in 0.91, it made building bigger asparagus stacks kinda tricky