[0.23.5] Spherical and Toroidal Tank Pack (Updated 05/02/14) (New download link)

[RoboRay]

I think those are great ideas. Maybe I'll expand this into a whole Spherical Parts Pack! I haven't looked at the intricacies of doing IVA's yet, but it is definately something that I'll take a swing at. Thanks for the input, RoboRay.

Hey, I'm great at coming up with work for other people to do!

Even without an IVA, a large crew habitat module would be a very useful part... basically the current Hitchhiker module on steroids, able to hold a lot more kerbals.

[Wyseman76]

Talisar, I am creating a new texture for personal use when I realized you have the medium tank using the .png format and the large using the .mbm format. Is it possible to have the large tank in the .png format as well. Forgive me if I'm imposing. When I am done I can PM you the texture if you would like.

[Talisar]

Not a problem at all, I'll dig it up and send it to you. They're almost identical templates

[Greys]

Just sharing, the Fustek Munox parts work pretty well making sphereships, and it turns out 9 mainsails and a full large tank is almost exactly enough to get into orbit, if you're careful.

In the end I had about 400 units of each left over, SSTO.

These are definitely my tank of choice going forwards.

[Mihara]

Tried the math myself... Something is still off here. Let's compare it to the benchmark orange tank since they so neatly line up side by side.

The volume of a sphere is (4*Pi*a^3)/3 where a is the radius of the sphere. The volume of a cylinder is Pi*b^2*h, where b is the radius of the cylinder and h is the height of the cylinder.

The biggest tank is as tall as the orange tank, so we can assume h to be a/2. b we know to be 2.5/2. You said that a = 7.5/2, i.e. that the big spherical tank is 7.5m across at the widest point.

As a result the volume of the large spherical tank is ~220.9 (cubic meters) while the volume of the orange tank is 58.9 (cubic meters). Whatever the densities and units of the fuel, your large spherical tank should contain no more than 3.75 orange tanks, not 9 orange tanks as it is now.

At the correct ratio of fuel to oxidizer, that means that it should contain 10800 units of liquid fuel and 13200 units of oxidizer.

[Talisar]

Ok, that makes sense to me. Now if I use the figures that Greys came up with for the densities of the various resources in another thread (I hope you don't mind me stealing your research, Greys):

I was dealing with this recently and the basic issue is that units of resource are not liters; they're also not the same between resources.

Based on analyzing the volumes vs resources of a few stock parts I have determined that:

LF/Oxy = 173.913 units/m^3

Monopropellant = 129.87 units/m^3

Xenon = 4875 units/m^3

Battery = 1785.714 units/m^3 & 5.6 tons/m^3 (because electricity doesn't have weight*)

Using these figures, it seems that the large tank should have a total fuel/oxy capacity of 37,976, coming to 17,089.2 units of LiquidFuel and and 20,886.8 units of Oxidizer.

I have another update coming to these tanks very soon, and I'll adjust the capacities again on that one. I'd like you guys to check the figures on these so I can get them finalized so I don't irritate people by changing them constantly. I'd hate to have someone build a great rocket and then get stuck halfway to Jool because I cut their fuel capacity in half. My goal is to have them as closely in line with the stock tanks as possible.

[Scotius]

This is insane amount of fuel, indeed. On the one hand it is nice to have all this fuel in one big tank, instead of multiple smaller ones - my CPU greatly enjoys lowered part count, pumping fuel around is easier, and my space station looks less like an effect of horrible industrial accident. On the other hand...filling this mega-tank takes multiple launches of my standard, jumbo-based tanker. Guess i can't have everything

[Talisar]

Lol, and there in my post I demonstrate a basic misunderstanding of physics. They wouldn't get stuck halfway to Jool, they just wouldn't be able to stop when they get there.

[Scotius]

Unless they'd run out of fuel half-way through transfer burn

[Greys]

Just so you know Talisar, there's a point in the operation where a part goes from based on the part definition, to concretely duplicated and irrespective of changes to the part; I'm not entirely sure where this is, but I know that it has happened by time you get into the flightspace; so if somebody's on their way to Jool now, nothing you do will mess that up for them, and I suspect this point is actually when you put the thing on the ship in the VAB/SPH.

[Mihara]

Using these figures, it seems that the large tank should have a total fuel/oxy capacity of 37,976, coming to 17,089.2 units of LiquidFuel and and 20,886.8 units of Oxidizer.

That's still ~6 orange tanks, though. Closer to sensible than the 9, but I can't say it's settled.

It could be that you're off when you said it's 7.5m in diameter -- for example, because of the native scaling (1 unit of model size is scaled to 1.25 in KSP if my memory serves me right, so I might simply be wrong about the length of an orange tank, which isn't precisely known) but I'd say it needs further investigation.

so if somebody's on their way to Jool now, nothing you do will mess that up for them

Except giving the part a different name, that is. Then KSP will refuse to load the flight and destroy it.

[Talisar]

Nice, I won't feel too bad about making the adjustments then. And speaking of adjustments, I'd like you all to check my math here (especially Greys, since I'm using your figures on fuel density).

I now have 3 tanks just about ready to update:

Small Tank (0.625m endcap, 2.5m diameter) Volume = 8.2 cubic meters = 640 units of LiquidFuel and 782 units of Oxidizer OR 1,065 units of MonoPropellant

Medium Tank (1.25m endcap, 3.75m diameter) Volume = 27.6 cubic meters = 2,160 units of LiquidFuel and 2,640 units of Oxidizer OR 3,580 units of MonoPropellant

Large Tank (2.5m endcap, 7.5m diameter) Volume = 220.9 cubic meters = 17,200 units of LiquidFuel and 21022 units of Oxidizer OR 28600 units of Monopropellant

I did a little bit of adjustments to the numbers in order to get close to nice round amounts, but I think these are pretty reasonable figures. Please let me know what you think

[Talisar]

That's still ~6 orange tanks, though. Closer to sensible than the 9, but I can't say it's settled.

It could be that you're off when you said it's 7.5m in diameter -- for example, because of the native scaling (1 unit of model size is scaled to 1.25 in KSP if my memory serves me right, so I might simply be wrong about the length of an orange tank, which isn't precisely known) but I'd say it needs further investigation.

I'm certain about the diameter, as I modeled it at 6m so the scaling would increase it to 7.5m. I think the difference must be in the orange tank size. Greys appeared to have done quite a bit of figuring using several different models to come up with his density figures, so I applied those to the volumes that I modeled. Please let me know if my math on these is correct, as I haven't done much of this lately

[Mihara]

Please let me know if my math on these is correct, as I haven't done much of this lately

Wolfram Alpha helps with math.

Actually, wait, I must've been off the first time, it says that the orange tank which is 2.5m in diameter and 7.5m tall has a volume of 36.82m^3 while the sphere 7.5m in diameter has a volume of 220.9m^3 . I.e. the sphere has 5.99 times the volume of the orange tank of the length equal to it's diameter, so yes, your last estimate appears to be close enough.

[Mihara]

Oh, by the way, idea.

How about a 2.5m endcap version of a medium tank?

[Commander Zoom]

Same size sphere, bigger endcap?

[Mihara]

Yes. This way, stacking a medium tank of RCS and a large tank of fuel would make an instant nice-looking fuel depot.

[Talisar]

Oh, by the way, idea.

How about a 2.5m endcap version of a medium tank?

This is actually the next thing on my list. I'm going to make half-sphere versions of each type of tank. As it's mostly just cutting the model in half and doing a bit of work on the bottom, it shouldn't take long. I like the idea of the endcap version too. Like 2.5m base with the 1.25 endcap sound about right?

Edited May 25, 2013 by Talisar

[Mihara]

That would be helpful too (PARTS FOR THE PART GOD! Ahem.) but I was thinking specifically of a spherical medium tank with an extra 2.5m cylinder stuck through it kind of shape. Most of my space stations are built to have as few parts as practical, so they naturally gravitate to a simple cylinder -- to keep them more manageable and easier to dock at, I've been using smaller numbers of wider and wider tanks.

Your spherical tanks are a natural progression, (and are more aesthetically pleasing than just about everything else I've been using) but such a station works best structurally (and in terms of wobble) when it's a single stack of the same width elements with as little adapters as possible.

[cxg2827]

awesome parts.

would you also consider make 2 more iterations of smaller sizes? (1/2 diameter of small, and 1/4 diameter of small)

[Talisar]

That would be helpful too (PARTS FOR THE PART GOD! Ahem.) but I was thinking specifically of a spherical medium tank with an extra 2.5m cylinder stuck through it kind of shape. Most of my space stations are built to have as few parts as practical, so they naturally gravitate to a simple cylinder -- to keep them more manageable and easier to dock at, I've been using smaller numbers of wider and wider tanks.

Your spherical tanks are a natural progression, (and are more aesthetically pleasing than just about everything else I've been using) but such a station works best structurally (and in terms of wobble) when it's a single stack of the same width elements with as little adapters as possible.

I'm not certain I understand what you mean. The medium tanks right how have the 2.5m endcap and a 3.75m diameter. Do you mean another connector cap at right angles to the first? Or have the existing caps extended out from the ends more on a cylinder?

awesome parts.

would you also consider make 2 more iterations of smaller sizes? (1/2 diameter of small, and 1/4 diameter of small)

I can put it on my list the 1/2 diameter of the small would be 1.25m, and I could probably make that work with the .0625m endcap, but on a model smaller than that I think having a useable sized cap would completely hide the sphere. Unless you are just looking for a teeny tiny tank to surface attach on probes, then I guess the endcap size wouldn't really matter. It just wouldn't be stackable.

[cxg2827]

I can put it on my list the 1/2 diameter of the small would be 1.25m, and I could probably make that work with the .0625m endcap, but on a model smaller than that I think having a useable sized cap would completely hide the sphere. Unless you are just looking for a teeny tiny tank to surface attach on probes, then I guess the endcap size wouldn't really matter. It just wouldn't be stackable.

for the 1/4 diameter, I was thinking maybe you can implement encaps the same size as the Oscar B fuel tank, and not have the radial band that the other ones have.

[Talisar]

This is what I thought of when you said a 2.5m endcap

Basically it's a spherical nose/tail cone that holds fuel. Or you can make a full sphere that is half LFO and half RCS fuel

[The Tempest]

These are some cool parts! I'm just having issues with connections. It was a bit wobbly so I was going to weld the bottom node with the Lazor System, but it says the part connected to the node is 6m away.

I know one fix is to edit the .cfg of the parts I attatch, but the 6m distance is odd

EDIT also these parts seem strangely laggy. I'm doing tests with a 5 part vessel that has 2 large, empty tanks, and I'm getting tons of lag.

Edited May 26, 2013 by The Tempest

[Commander Zoom]

Okay, if I'm understanding right, when we say "endcaps", you should read "connector cap(s)". Something that looks a bit more like this very quick and dirty sketch:

Same tank dimensions/volume, larger connectors.