Give the LV-T30 some gimbal

[CaptRobau]

Back when the LV-T30 was introduced, its stats made (some) sense. You could only travel around Kerbin, maybe try to get in orbit. A realistic range of engines wasn't needed, so having an engine that gave you thrust vectoring and one that didn't was okay. Using the T30 on its own made for some fun crashes, entertaining people, and when combined with a T-45 for some control it had a bit of use to get you into orbit.

Then the rest of the updates came and changed the entire game, from a simple crash tool to a space exploration game complete with a whole solar system and technogical progression. Yet, the T-30 barely got any attention. As a result it's not getting a lot of use from me. The lack of thrust vectoring means it's useless on its own, especially when it's the engine doing the gravity turn. The rest of the stats are fine, making it a more powerful first stage rocket to complement the upper stage T45 and the vacuum-specialized LV-909 engine. But without a bit of control of its own, it only gets a role as a supporting engine with control surfaces and/or vectoring engines providing rocket control.

Aside from nostalgia, I see little basis to keep its lack of thrust vectoring. Virtually all rockets (even SRBs) have some gimbal-like control mechanism, whether it be an actual gimbal or thrust vanes (ex. V2 rocket, Mercury-Redstone). It'd also make it a more interesting engine for early career mode, as it would make it easier for new players to handle liquid-fueled rockets (otherwise they have to wait till the LV-T45) and it'd make those early 1.25m designs more interesting. For more experienced players it would also gain more uses.

In conclusion, I suggest adding some (limited) gimbal/thrust vectoring to the LV-T30. Added: to offset the similarity between the growing similarity that the T45 and T30 will have with a gimballed T30, I suggest also changing the Isp of one of the engines. A lower Isp for the T30 is the most logical choice. This would also place it more in line of other first stage engines like the Mainsail or the 25x4.

Edited December 17, 2014 by CaptRobau
Clarification

[Jouni]

If the LV-T30 gets thrust vectoring, we need some way to differentiate the more advanced LV-T45 from it. Then we'll probably have to rebalance the Poodle somehow, which in turn may force us to reconsider the stats of many other engines.

[CaptRobau]

Give the T30 lower Isp and it's solved. Then it'll be like any other lower stage engine: highest TWR of its size (already the case with the T30), but lower Isp. The T45 will then remain the second/upper stage engine it's often used as.

[GateCrasherVI]

Isn't a T30 with lower ISP and gimbaling basically just a T45?

[Captain Sierra]

If the LV-T30 gets thrust vectoring, we need some way to differentiate the more advanced LV-T45 from it. Then we'll probably have to rebalance the Poodle somehow, which in turn may force us to reconsider the stats of many other engines.

The game as a whole needs a good thorough balance pass. Squad has to know this the way we gripe about it. I'd say expect to see one come during beta. That said, if we wanna help them out, we should have a discussion, and compile a full list of rebalances that work well together (rather than just recording all ideas and making the devs sort through that mess).

[Tw1]

Not having gimbaling is the point of the LV-T30. If you remove that property, you might as well remove the engine, or the LV-T45- as Jouni says, it will be just like the LV-T45.

Edited December 17, 2014 by Tw1

[TKO]

I have to agree with @Tw1 here -- if you add a gimbal to the LV-T30, it's very close to being an LV-T45, so why not just remove it?

That said, I do use the LV-T30 on occasion. (Usually on radial tanks, when I have a larger mainsail or skipper powered central tank.) I still find it useful. I think it should stay.

[CaptRobau]

A T30 with gimballing and worse Isp is to the T45 what the Mainsail is to the Skipper. Those are clearly different and don't need to be removed. With the changes mentioned, the Mainsail/T30 are the higher TWR/lower Isp first stage engines. The Skipper/T45 would are the lower TWR/higher Isp upper stage engines.

[King Arthur]

It's as simple as just using the T45 (or combining the two) if you need vectoring. The lack of vectoring on the T30 is a non-issue early in career mode since your rockets will be small and easy to push one way or another anyway; going larger and later the T30's lack of gimballing and higher TWR make it shine as a booster or supporting core engine in launchers.

Most of the stock parts need a thorough rebalance at some point, but the LV-T30's pretty low priority on the list as far as that is concerned.

[impyre]

It's as simple as just using the T45 (or combining the two) if you need vectoring. The lack of vectoring on the T30 is a non-issue early in career mode since your rockets will be small and easy to push one way or another anyway; going larger and later the T30's lack of gimballing and higher TWR make it shine as a booster or supporting core engine in launchers.

Most of the stock parts need a thorough rebalance at some point, but the LV-T30's pretty low priority on the list as far as that is concerned.

It's funny you say that, because I actually use them the other way around. I use the 30 as the main engine and the 45's as the boosters. You need gimbal most when you're at your heaviest and in the thickest part of the atmosphere, so I use the 45's to add that lil bit of extra thrust and control. Once I get lighter and higher I ditch the 45's, by this point i'm high enough and light enough that the 30 is enough by itself. (at least this works well on smaller launch vehicles)

[Vaporo]

Stats of the LV-T30

Stats of the LV-T45

As far as I can tell, the only differences between the two engines are:

Thrust vectoring

Slight thrust difference

Slight weight difference

Slight ElectricCharge generation difference

Cost

As it is, they already feel very similar to me. Lack of gimballing is the main thing that differentiates between the two engines. If you add gimballing to the LV-T30, you essentially get rid of any reason to use the LV-T45, as all its stats are worse than the T30's except for gimballing. The two are fine as it is, I think. You can have gimballing and slightly reduced engine performance, or no gimballing with slightly increased performance.

[CaptRobau]

An Isp reduction for the T30 would differentiate it again from the T45 and bring it more in line with other first stage engines like the Mainsail or KS-25x4.

[thereaverofdarkness]

I figure we should actually remove thrust vectoring from some of the engines:

* the 48-7S

* the Mainsail

* the KS-25x4

All three of those engines are plenty good enough without it, and not having it would not only differentiate them from other engines, but it would help to push people to find other ways to control their rockets. You give people too many training wheels, and they never learn that walking is possible.

[Darnok]

As it is, they already feel very similar to me. Lack of gimballing is the main thing that differentiates between the two engines. If you add gimballing to the LV-T30, you essentially get rid of any reason to use the LV-T45, as all its stats are worse than the T30's except for gimballing. The two are fine as it is, I think. You can have gimballing and slightly reduced engine performance, or no gimballing with slightly increased performance.

Agreed, IMHO it would be awesome to make it tweakable, so you could choose from different versions of same engine...

Simple way with two options for EVERY engine in game

- add vectoring

- lower thrust (5-15%)

- larger weight (0.5-1.0t)

- higher costs

or

- no vectoring

- better thrust

- lower weight

- lower costs.

OR make it more complicated with many options where we can tweak many engine stats

- vectoring (y/n)

- thrust (80%-120% of current thrust)

- weight (also +/- some value)

Now for example I want something with shape of LV-T45, but I don't need vectoring, I need largest thrust it can give me... after I am done with tweaks game should calculate weight and costs changes

It would be great for carrier mode as representation of technological progress.

[Jouni]

I figure we should actually remove thrust vectoring from some of the engines:

* the 48-7S

* the Mainsail

* the KS-25x4

All three of those engines are plenty good enough without it, and not having it would not only differentiate them from other engines, but it would help to push people to find other ways to control their rockets. You give people too many training wheels, and they never learn that walking is possible.

I could agree with removing thrust vectoring from the 48-7S, but not from the other two. The Mainsail and the KS-25x4 are sustainer engines for large rockets. Such rockets can't really be controlled with reaction wheels or RCS, so they need thrust vectoring. Furthermore, it's usually a better idea to use thrust vectoring in the sustainer engine and to disable it in the boosters than the other way around, as this reduces the amount of strutting the boosters require.

[orangexception]

The LV-T30 is one of the best engines in the game. It's already fantastic.

[Giggleplex777]

If anything, the LV-T30 would have a higher specific impulse than the T45 due to its larger engine bell. I think it would be better just to increase the gimbal range of the T45 and make the T30 more expensive.