[1.4] SpaceY Heavy-Lifter Parts Pack v1.17.1 (2018-04-02)

[StevieC]

SpaceX's layout is 1 engine in the centre, surrounded by six engines, then a small gap betwixt that and a circle of 14 engines, and finished out 'round the edge with a ring of 21 engines 1+6+14+21=42, but that's not exactly symmetry-friendly. For a more symmetry-friendly KSP thrust-plate, I recommend omitting the single engine from the centerline. That way you can have 6 engines in the center ring, 24 engines around the edge, and a ring of 12 engines in between the center and edge? 6+12+24=42

[.50calBMG]

Or he could do what he did with his other engine groups and make one engine with 42 engines and do a mode switch.

[StevieC]

I've actually been attempting to figure out what the largest number of engines is I can fit into the 5m diameter fairing without clipping any parts into each other.

[TiktaalikDreaming]

1 hour ago, StevieC said:

I've actually been attempting to figure out what the largest number of engines is I can fit into the 5m diameter fairing without clipping any parts into each other.

https://en.wikipedia.org/wiki/Circle_packing_in_a_circle
 

[Kerbas_ad_astra]

2 hours ago, StevieC said:

SpaceX's layout is 1 engine in the centre, surrounded by six engines, then a small gap betwixt that and a circle of 14 engines, and finished out 'round the edge with a ring of 21 engines 1+6+14+21=42, but that's not exactly symmetry-friendly. For a more symmetry-friendly KSP thrust-plate, I recommend omitting the single engine from the centerline. That way you can have 6 engines in the center ring, 24 engines around the edge, and a ring of 12 engines in between the center and edge? 6+12+24=42

Or, go ahead and keep the centerline engine...then say "This booster goes up to 43".

[TiktaalikDreaming]

4 minutes ago, Kerbas_ad_astra said:

Or, go ahead and keep the centerline engine...then say "This booster goes up to 43".

A pattern of six leaves a gap in the middle.  You can leave the stack node there for anyone who wants the volume to go to 43.

[NecroBones]

2 hours ago, StevieC said:

SpaceX's layout is 1 engine in the centre, surrounded by six engines, then a small gap betwixt that and a circle of 14 engines, and finished out 'round the edge with a ring of 21 engines 1+6+14+21=42, but that's not exactly symmetry-friendly. For a more symmetry-friendly KSP thrust-plate, I recommend omitting the single engine from the centerline. That way you can have 6 engines in the center ring, 24 engines around the edge, and a ring of 12 engines in between the center and edge? 6+12+24=42

2 hours ago, .50calBMg said:

Or he could do what he did with his other engine groups and make one engine with 42 engines and do a mode switch.

33 minutes ago, Kerbas_ad_astra said:

Or, go ahead and keep the centerline engine...then say "This booster goes up to 43".

28 minutes ago, TiktaalikDreaming said:

A pattern of six leaves a gap in the middle.  You can leave the stack node there for anyone who wants the volume to go to 43.

 

Yeah, it's a tough call. One of the things I'm having to contend with is that the 5m parts were the primary point of SpaceY, but it was parodying SpaceX's Falcon 9, which is 3.66m. Technically the stock 3.75m parts are wider than the real Falcon 9, so in a rare case for KSP and mods, SpaceY is actually bigger than the real thing. This is translating forward into this new rocket. As far as I know, the ITS is around 12m in diameter (I heard 14m speculated too). But if I were to make 3 concentric rings of 2.5m engine mounts, we're looking at something like 17.5m diameter. I could probably squish that down to 15m if the nodes are designed to clip 2.5m engines into each other (2.14m spacing). But I forget how wide I made the R1 engine bells. I'll have to check that.

 

There's also that possibility of making prefab engine clusters, but what a royal pain it is to make big clusters. If I took that route, I'd probably split the underside of the rocket into 6 sections and make a cluster that can be mounted with 6x symmetry, but this is an ugly choice, I think.

 

Also perhaps getting ahead of myself, SpaceY doesn't have 10m parts yet, let alone 15 or 17.5. These large parts probably belong in the Expanded pack, with 10m and 15m options. Wow. (still not the biggest thing I've made though, since the Sea Dragon was around 23m).

 

 

[StevieC]

No, I meant 3 concentric rings of 1.25m diameter engine mounts, not 2.5m engine mounts.

I should note Musk emphasized only the center 7 engines of his booster design have gimbals; both outer rings are fixed-mount engines with no gimbals, to lighten the booster's total dry mass. This is part of why I think the 1.25m engine size would be more appropriate: Reliants on the outer two rings, Swivels on the 7 center attach points.

Edited September 29, 2016 by StevieC

[StevieC]

1 hour ago, TiktaalikDreaming said:

https://en.wikipedia.org/wiki/Circle_packing_in_a_circle
 

Allow me to rephrase: I've been attempting to figure out how many engine mounts of the specific relative sizes available to us in KSP can fit in each diameter (so, how many 1.25m engine mounts can be fit inside of a 5m diameter circle, which as far as I can tell appears to be ten) It appears that we can fit up to 19 1.25m engine mounts in a 7.5m circle, and 43 is the max we could fit into the 10m circle.

[TiktaalikDreaming]

1 hour ago, StevieC said:

Allow me to rephrase: I've been attempting to figure out how many engine mounts of the specific relative sizes available to us in KSP can fit in each diameter (so, how many 1.25m engine mounts can be fit inside of a 5m diameter circle, which as far as I can tell appears to be ten) It appears that we can fit up to 19 1.25m engine mounts in a 7.5m circle, and 43 is the max we could fit into the 10m circle.

You should be able to fit 9.  6 circles in a hex pattern is 3 circles wide, so if those are 1.25m parts, then that hex is only 3.75m across. 

For anything larger than 1, the size of the outer edge of a circle bounding N circles of the same size is ((1/sine(pi/N)-1)+2, or

Circles	Ratio Bounding Circle
1	1
2	2
3	2.1547005384
4	2.4142135624
5	2.7013016167
6	3
7	3.304764871
8	3.6131259298
9	3.9238044002
10	4.2360679775
11	4.5494655329
12	4.8637033052
13	5.1785814689
14	5.4939592074
15	5.8097343447
16	6.1258308955
17	6.4421911518
18	6.7587704831
19	7.075533821
20	7.3924532215
21	7.7095061398
22	8.0266741833
23	8.3439421961
24	8.6612975755
25	8.9787297556
26	9.2962298106
27	9.6137901485
28	9.9314042704
29	10.2490665803
30	10.5667722335
31	10.8845170144
32	11.2022972374

[.50calBMG]

Like stevie said, only the inner engines have gimbling on them, so maybe you could split it up into two parts; the outer two rings being their own piece at 7.5 or 10m, and a seven nozzle inner part at 2.5 or 3.75m with gimbling on a hidden attachment node. The video showed the boost-back burn with the center cluster and the middle ring firing all at once, but the landing was only on the center cluster. If you did it that way, you wouldn't have to worry about multiple mode switching or setting 42 engines individually.

Edited September 30, 2016 by .50calBMg
missed something

[TiktaalikDreaming]

3 hours ago, NecroBones said:

As far as I know, the ITS is around 12m in diameter (I heard 14m speculated too).

The main tank body is 12m.  Outer diameter to contain all the poking out bits, (especially the Interplanetary craft section) is apparently 17m.  There's some really nice charts floating around apparently made from the CAD data (but no CAD files, dammit!).

[StevieC]

Two other types of interstage thrust plates I'd like to see are 1x1.25m-2x0.625m and 1x2.5m-2x1.25m that are the right thickness that when put on the center of the "Rose" thrust-plates will put their smaller attachment points level perfectly with the eight periphery attachment points on the "rose" so I can build a 10-engine array

[NecroBones]

 

Yeah, this is starting to sound like the best starting point will be some 10m tanks, and a 43-node thrust plate with 1.25m nodes. The nice thing about 10m, is that it's also the real world scale of the Saturn V, so a 5-way adapter for the E1 engines might be in order too.

 

[StevieC]

38 minutes ago, NecroBones said:

 

Yeah, this is starting to sound like the best starting point will be some 10m tanks, and a 43-node thrust plate with 1.25m nodes. The nice thing about 10m, is that it's also the real world scale of the Saturn V, so a 5-way adapter for the E1 engines might be in order too.

 

On second look, it seems that 43 might not be the best number, unfortunately. I did find this website which has some information that may aid in choosing the closest number of engines to Musk's 42 that could feasibly be packed into a fairing size that's easily worked with in KSP. It offers perfect configurations for 19, 31, 37, 61, and 91, and workable configurations for 12, 15, 27, 30, and 55 (the purple circles are ones that don't touch any other circles and therefore might 'rattle' a bit)…

On second thought, that one for 55 might be something that we could potentially re-work to make fit 43 engines. since the middle and outer rings will have gaps separating them from their neighboring rings of engines

also, do you think you can make a 1x1.25m=2x0.625m thrust-plate and a 1x2.5m-2x1.25m thrust-plate that can be put in the "Rose" thrust-plates and fit flush with the 8 outer attachment nodes?

Edited September 30, 2016 by StevieC

[Kerbas_ad_astra]

1 hour ago, StevieC said:

On second thought, that one for 55 might be something that we could potentially re-work to make fit 43 engines. since the middle and outer rings will have gaps separating them from their neighboring rings of engines

Using the 55-circle layout as the basis would also work well because 8.21 x 1.25 = 10.26 ~ 10 meters (plus a little flare at the bottom).  In fact, if you delete the 12 green circles (to get to 43) and pull in the purple circles to touch the hex block, you get to 9.91 m, so you'd have some leeway to space things out a little.

[StevieC]

I present to you this screenshot to show why we need a 1x2.5m-2x1.25m adaptor: as you can see, it would allow on to mount up to ten engines, without part-clipping, within the diameter of a single 5m circular bulkhead. Similarly, a half-sized version of it would allow for ten 0.625m diameter engines to fit on the back of a 2.5m diameter fuel-tank without clipping. It would be optimal if the adaptor plate, when mounted to the center node of a "Rose" thrust-plate, fit its two smaller nodes to fit flush with the Rose plate's outer 8 nodes.

[NecroBones]

Yep, I think some small adapters for the rose plate are certainly doable. I'll take a look at that too.

 

Agreed on using the 55-circle as the basis. Because it's still a hex pattern throughout, 6-way symmetry should still play nicely with it. That means placing 7 engines in the UI to get to 42, and an 8th one if you want a 43rd engine in the center. The adapter's description text could even make a comment about it being the new and improved model, with a "bonus" 43rd slot.

 

This of course necessitates some 10m tanks. Oh darn. Finally an excuse to add 10m parts. The good news is I already set aside some color-coding in the textures.

 

[NecroBones]

On 10/1/2016 at 9:06 PM, NecroBones said:

The good news is I already set aside some color-coding in the textures.

 

 

... which apparently I ended up using for other things. LOL. No biggie, I really only need to add some color-specific bit for tank caps and the like. I'm not worried!

 

[NecroBones]

 

This might be a really good start. 43.. 37 engines, supporting 6-way symmetry as planned, but still preserving the "rings of engines" sort of arrangement:  I could possibly push those outer rings outward a little more too. But I also want to leave room for a shroud, in case anyone wants to use this monster as an upper stage (10m).

EDIT: Even though I'm posting this here, I should be clear that since it's a new diameter, it'll belong in the Expanded pack.

 

EDIT 2: Oops, this is 37 engines in this arrangement. I may offer this as an option, but I can still get the 43 to work too, I believe.

 

[StevieC]

Too bad we can't implement differential throttling for the two outer-rings, that'd mean that we would only need to use gimballing on the inner ring for roll-control.

EDIT: Minor suggestion for a name-change of some of the main SpaceY thrust-plates. For the 1x2.5m to 1x1.25m+8x0.625m thrust plate and the corresponding 1x5m to 1x2.5m+8x1.25m thrust-plates, you've named them both the "Rose". May I suggest amending the smaller model's name from "Rose" to "Rosette" as a play on its diminutive dimensions relative to the 5-meter model? And to add the name "Honeycomb" on the 1x3.75m to 7x1.25m thrust-plate, in reference to its hexagonal geometry?

Edited October 3, 2016 by StevieC

[NecroBones]

 

I just caught my mistake that the above is 37 engines. I'll have to do the original hex pattern to get to 43, I think. I'll probably make both versions.

 

[NecroBones]

 

43-node arrangement:

 

 

37 node arrangement again, for comparison:

 

[NecroBones]

 

37 Vector engines. Holy Jeb, it's insane.

 

[Andem]

1 hour ago, NecroBones said:

37 Vector engines. Holy Jeb, it's insane.

why