Vector engines?

[Sweetnsaltyish]

okay, i understand the large gimbal range, and the high thrust, but it's hardly efficient, and i'm having trouble finding ideas on how to use them as a later stage.

 

any ideas?

[Laie]

In terms of performance they're 1/4 Mammoth and should be seen in that light: boosters, from the ground up.

IIRC they were intended as space shuttle engines, hence the high gimbal range (you need it if you want to balance a vessel that looks like the real space shuttle). Hence also the high cost, as you're supposed to recover them.

More generally, they're for when you need a lot of oomph from a small mount point, never mind the price tag.

More specifically, they're about the best if you ever want to take off from Eve.

[M_Rat13]

Why do you need them as an upper stage? High thrust in space? Use a rhino engine instead.

[GRS]

Vectors are bad for Upper stage, trust me, they're great for Eve Landers and Kerbin Ascent...

[Loskene]

They also happen to be more dense than ore tanks and so make great ballast for submarines 

[Tweeker]

The Vector engine has always been OP, and broken.   A lot of people use them in clusters,  as they have Far more thrust than you would get otherwise, 

From this topic, 

https://forum.kerbalspaceprogram.com/index.php?/topic/124844-vector-engine-possibly-a-little-too-good/&do=findComment&comment=2272192

 

[Aeroboi]

• Great for high thrust rockets. (Some SSTO rockets of mine have 4 TWR, heat resistance and aerodynamics to break orbital velocity @25km altitude) This is especially handy for SSTO rockets as it lessens Dv requirement. You want as much thrust on such vessels as bottom attachment nodes allow, the vector will be the obvious choice.
• Vectors have the greatest thrust per cross section. The cross section is the frontal surface area of the vessel which is 1.25m. A vector has 1000Kn per 1.25m so it's thrust is very overpowered.
• And while its thrust to cross section is overpowered it also has a good atmospheric/vacuum ISP range making it good for Eve lifters + they are very aerodynamic so you can surface attach them without using a nosecone and they wont cause any/much drag.
• Good for submarine ballast as mentioned.
• Good for rocket powered VTOL engines like on oxygen less bodies. Because their gimbal is superb you can use them to rotate even if the CoM shifts (try to minize that anyway)

Edited March 27, 2019 by Aeroboi

[Tweeker]

14 hours ago, Aeroboi said:

Vectors have the greatest thrust per cross section. The cross section is the frontal surface area of the vessel which is 1.25m. A vector has 1000Kn per 1.25m so it's thrust is very overpowered.

Just FYI, here is the cross sectional area of the different sizes, 

0.625	1.25	1.875	2.5	3.75	5
0.306758	1.227031	2.76082	4.908125	11.04328	19.6325

You can calculate the thrust per cross sectional area based on this, 

 

LV-N	11.31186
Terrier	12.04533
Poodle	13.09869
Spark	55.02712
Rhino	109.1161
Skipper	115.8793
Aerospike	125.1231
Swivel	136.8914
Reliant	167.2003
Mainsail	280.9688
Vector	763.2324

 

 

 

[ExtremeSquared]

They are only cheaty if you don't apply the honor system to their intended use when building. To actually code them to only work with engine plates and mounts would probably be more difficult than it's worth.

[Tweeker]

1 hour ago, ExtremeSquared said:

They are only cheaty if you don't apply the honor system to their intended use when building. To actually code them to only work with engine plates and mounts would probably be more difficult than it's worth.

Actually it would be very simple,  just a small change in the .cfg, If you  have notepad you can do it.

literally just changing a 1 to a 0. 

 

As you can see most engines have only "stack" and "allowStack" 

IIRC The vector has attachment rules of 1,1,1,0,0  or allow surface attach. 

But even without clustering it is OP,  it has a stupidly high thrust to cross section,  2.7 times higher than the next closest LF engine.  

 

 

 

 

 

Edited March 28, 2019 by Tweeker

[Aeroboi]

9 hours ago, Tweeker said:

Actually it would be very simple,  just a small change in the .cfg, If you  have notepad you can do it.

literally just changing a 1 to a 0. 

 

As you can see most engines have only "stack" and "allowStack" 

IIRC The vector has attachment rules of 1,1,1,0,0  or allow surface attach. 

But even without clustering it is OP,  it has a stupidly high thrust to cross section,  2.7 times higher than the next closest LF engine. 

Beyond that it has this ridiculous gimbal effect along with it making it OP in more then one area.
What amazes me is that these Vector engines were introduced as replica parts for the spaceshuttle main engines.
But that makes no sense because the Mk3 modules to create a stock a like space shuttle does not require 3 Vector engines as that would be to overpowered, and IIRC (IIRC = stating the obvious) the space shuttle had 3 of them and using 2 of them with traditional SRB's and you are already over thrusted. So Vectors as SSME's seems hardly a resembling balance if you ask me.

For balance purposes I would shrink or re-specify the Vector engine to be balanced and have a unique engine for atmospheric purposes, linear aerospikes or vaccuum optimized nozzles.
The worst part about Vectors is that they produce little to no drag. So when you surface attach them you don't have to add cones on top of them. IME it makes no difference and terminal velocity is more or less the same. That means you can stack them at the underside of a Mammoth engine.

If you drag them tight enough you can add 5 Vectors to the underside of a Mammoth engine without them clipping into one another creating a 9000Kn effective 3.75m engine.
That's another complaint, their ease of attachment while already boasting those other top notch specifications.

Of course the trade off is it's cost, but I never play career, so I don't care. And it's not about cost but about gameplay and balance. If a digitized budget number is going to give value then it will have little consequence outside of career mode. And scrapping the cost element it is just a ridiculous engine that seems like it's made out of a artificial alloy.
I wouldn't want the Vectors benefits to be lost, we need a overpowered exotic or otherwise high thrust and/or vacuum optimized engines for the planetary bodies where one may require them.
I'm also not suggesting to mend or replace the vector, I have no issue to have it remained because OP things are never really that much of a pest.

But in retrospect and serious analysis it's a bit wacky why the vector is so OP and I'm sure many will agree.

 

 

Edited March 28, 2019 by Aeroboi

[MisterKerman]

Surprisingly informative thread... will come back later for reference. Thanks guys!

[Tweeker]

54 minutes ago, Aeroboi said:

 But in retrospect and serious analysis it's a bit wacky why the vector is so OP and I'm sure many will agree.

 

     I usually get quite a bit of grief  any time I bring it up. So I avoid the subject unless someone brings it up.

        The gimbal range isn't really that much of an issue, it closely matches the SSME. Thrust, size, and attachment mode are the real issues. 

   It ends up being over powered thrust-wise because it is a 1/4 mammoth and the mammoth was introduced paired with the very wimpy kickback,

IRL the ratio of their thrusts would be about 6:1 favoring the "kickback"

In KSP it is     0.6:1.

The Kickback really needs to be about 2,500 thrust, and 2.5M to be somewhat acurate. 

That would let you scale the vector back to where it need to be, about 450 thrust. 

That would somewhat fix the issue,  but it is still too small for it's thrust. When it was introduced, there was no 1.875m size, that is is what it needs to be, about 66% scale. Which would match with the 2.5m kickback, (67.38%), &  the 3.75m shuttle parts, (72.11%). 

   That would put it at about 166 thrust to cross-sectional area, Right around the Reliant. And it would make for a much more realistic shuttle. 

 

[ZooNamedGames]

Admittedly the Vector is a bit OP, but what would help is to create rocket engines that provide similar functions, such as high thrust, but 0 gimbal 1.25m engines, or a Vector with high efficiency but low thrust, optimizing it for second stage engines. Etc etc.

[Snark]

On 3/27/2019 at 1:19 AM, Tweeker said:

The Vector engine has always been OP, and broken.

On 3/28/2019 at 7:37 AM, Aeroboi said:

For balance purposes I would <rebalance ideas>

I agree with these-- that engine bugged the heck out of me from the moment it was introduced.

In fact, that's what prompted me to produce my first mod ever. 

It's just a little ModuleManager patch that does the following:

• Renames it to the "Viktor"
• Leaves the size alone
• Removes the "surface attach" ability
• Reduces the gimbal down to what's typical for KSP engines
• Scales down both mass and thrust to 45% of their stock value, so that its thrust-per-cross-sectional-area is in line with the Mammoth.
• Makes it way cheaper, so that its cost-per-thrust is in line with other KSP engines

For anyone who may enjoy it. 

[ExtremeSquared]

On 3/27/2019 at 9:46 PM, Tweeker said:

Actually it would be very simple,  just a small change in the .cfg, If you  have notepad you can do it.

literally just changing a 1 to a 0. 

 

I'm saying that allowing it to stack / mount to 1.25m tanks is cheaty. Its TWR and size is supposed to take into account that it will always be attached to some giant 2.5m+ hunk of mounting hardware. Either way, it's the one engine that is not on a single craft I've built, because it still feels tacky.

[M_Rat13]

8 hours ago, ExtremeSquared said:

I'm saying that allowing it to stack / mount to 1.25m tanks is cheaty. Its TWR and size is supposed to take into account that it will always be attached to some giant 2.5m+ hunk of mounting hardware. Either way, it's the one engine that is not on a single craft I've built, because it still feels tacky.

Then what do you use instead? At the very least your rockets must be smaller than normal, which I guess is a good thing. Striving for smaller rockets is an admirably goal.

[Grogs]

 

On 3/27/2019 at 11:56 PM, ExtremeSquared said:

They are only cheaty if you don't apply the honor system to their intended use when building. To actually code them to only work with engine plates and mounts would probably be more difficult than it's worth.

I pretty much never use multiple vectors without an engine plate. I'm not sure how adding an engine plate at a fraction of a ton makes much difference when stacking 9 vectors at 36 tons of total mass and 9000 kN thrust though.

 

I do feel the vector is a bit OP overall, but one thing that doesn't bother me is the gimbal range. TBH, it has too much gimbal and I typically scale it down to about 20% when putting them on. Otherwise I find that my rockets will oversteer and porpoise around the prograde vector or in extreme cases actually be torn apart by the extreme gimbal.

[Aeroboi]

10 hours ago, ExtremeSquared said:

I'm saying that allowing it to stack / mount to 1.25m tanks is cheaty. Its TWR and size is supposed to take into account that it will always be attached to some giant 2.5m+ hunk of mounting hardware. Either way, it's the one engine that is not on a single craft I've built, because it still feels tacky.

Well, tbh if you used a 2.5m rocket with a conical end 2.5 to 1.25m adapter then a single vector producing 1000Kn of thrust would look more or less right.
Such a rocket will also be most aerodynamic.
Usually there's a plumbing system or pressure system to feed the engine. If presuming something like that consists inside a fuel tank or engine it would require some plumbing or pressure tank to feed the engines quikly enough. One Mammoth is 3.75m while 4 Vectors on a 4 way adapter attached to a 2.5m tank has the same thrust with much more Gimbal I must add. That seems way to strange and could be done differently. That means a 2.5m rocket can plumb fuel to 4 Vectors faster then a 3.75m rocket can plumb fuel to a single Mammoth. It seems rare to me.
I think we should have something like @Snark his "Viktor" engine for a properly balanced swap. Then added to that have a 1.875m engine with the same stats as the current Vector engine with shrouds to acommodate 1.25m attachment nodes but with the drag of a 1.875m part. IIRC the native drag of a Vector engine is very low so it should be a minor drag penalty.
 

Edited March 30, 2019 by Aeroboi

[M_Rat13]

3 hours ago, Aeroboi said:

Well, tbh if you used a 2.5m rocket with a conical end 2.5 to 1.25m adapter then a single vector producing 1000Kn of thrust would look more or less right.
Such a rocket will also be most aerodynamic.
Usually there's a plumbing system or pressure system to feed the engine. If presuming something like that consists inside a fuel tank or engine it would require some plumbing or pressure tank to feed the engines quikly enough. One Mammoth is 3.75m while 4 Vectors on a 4 way adapter attached to a 2.5m tank has the same thrust with much more Gimbal I must add. That seems way to strange and could be done differently. That means a 2.5m rocket can plumb fuel to 4 Vectors faster then a 3.75m rocket can plumb fuel to a single Mammoth. It seems rare to me.
I think we should have something like @Snark his "Viktor" engine for a properly balanced swap. Then added to that have a 1.875m engine with the same stats as the current Vector engine with shrouds to acommodate 1.25m attachment nodes but with the drag of a 1.875m part. IIRC the native drag of a Vector engine is very low so it should be a minor drag penalty.
 

Plumbing is a realism problem, not a game problem. Four vectors still chug as much fuel as a single mammoth (okay, maybe a little less due to drag, but not that much and the rocket will still be much taller if only using large rather than XL tanks).

If plumbing is that much of an issue, you'd need an entire overhaul of KSP to balance the tanks, not just an engine. That's going to take away from a lot of other things, and completely change the game. Is it worth it?

Honestly the thing I find silly is them not needing an attachment point. You can squeeze a ludicrous amount onto a tank, for super high thrust you couldn't otherwise get. If you forced them onto an attachment point, they'd be far less easy to abuse.

[ExtremeSquared]

6 hours ago, M_Rat13 said:

Then what do you use instead? At the very least your rockets must be smaller than normal, which I guess is a good thing. Striving for smaller rockets is an admirably goal. 

Large space stations, mines, even filled 5m fuel depots can all be put into orbit without vector clusters. Their corresponding 4km/sec+ dV interplanetary stages can as well, separately. Sometimes finesse is more enjoyable than brute force.

[T1mo98]

I might be a bit controversial here, but I would love an engine with about the same thrust as the Vector but with a much smaller nozzle. As someone who loves making replicas, often the Vector is the only engine than will do the job, except the nozzle is so big it looks way off, so maybe a smaller nozzle, 700-800kN and with worse stats when in Vacuum, to make it solely a booster engine. Otherwise I hope we get revamps of the Skipper and Mainsail to have a 1.25m and 1.875m size respectively so I would be less reliant on the Vector.

[M_Rat13]

2 hours ago, T1mo98 said:

I might be a bit controversial here, but I would love an engine with about the same thrust as the Vector but with a much smaller nozzle. As someone who loves making replicas, often the Vector is the only engine than will do the job, except the nozzle is so big it looks way off, so maybe a smaller nozzle, 700-800kN and with worse stats when in Vacuum, to make it solely a booster engine. Otherwise I hope we get revamps of the Skipper and Mainsail to have a 1.25m and 1.875m size respectively so I would be less reliant on the Vector.

I'm curious. Exactly what engines don't have a role, and how many of those are due to vector clusters?

[Aegolius13]

2 hours ago, T1mo98 said:

I might be a bit controversial here, but I would love an engine with about the same thrust as the Vector but with a much smaller nozzle. As someone who loves making replicas, often the Vector is the only engine than will do the job, except the nozzle is so big it looks way off, so maybe a smaller nozzle, 700-800kN and with worse stats when in Vacuum, to make it solely a booster engine. Otherwise I hope we get revamps of the Skipper and Mainsail to have a 1.25m and 1.875m size respectively so I would be less reliant on the Vector.

Agree, for whatever reason, KSP has had its nozzle sizes wrong (though it's getting better with some of the re-skins).  Vector is the most vacuum-optimized engine and has a pretty long nozzle, while the a lot of the vacuum engines (particularly the old Terrier and Poodle) had short nozzles.  

Vector apologists (kidding) might say that the Vector has to look the way it does because it's an SSME replica.  But I don't think it's really that much of an SSME analog anyway.  Too powerful for the Mk3 plane parts, and the ISP curve is too biased towards sea level.  

Thought bubble - it might be nice to have a single 2.5mm engine, skinned to have 3 SSME-looking bells, with Shuttle-appropriate stats.  Maybe ISP numbers similar to the Rhino but about half the power, and a bit better TWR.

[T1mo98]

34 minutes ago, M_Rat13 said:

I'm curious. Exactly what engines don't have a role, and how many of those are due to vector clusters?

I don't use the Twin-Boar, Rhino and Mammoth at all since a single or cluster of Vectors can do the job. Especially the Rhino since it's so big.

The Mainsail looks so ugly I don't want to use it and the Skipper has just too big a footprint imo.