Filling the gaps in the engine lineup?

[Galane]

With the thrust of the Poodle, LV-909 and KR-2L being severely nerfed, what would be reasonable thrust increases to restore them to the types of uses they had in previous KSP versions?

The poodle was ideal for small manned landers, even on Kerbin, due to its short length. The applications for the LV-909 were many. The KR-2L was the second most powerful engine but now Squad has puzzlingly made it weaker than the Mainsail. Is it now astoundingly more fuel efficient than the Mainsail? It would have to be as that would be the only reason to spend fuel lofting its mass and low thrust into space.

The Poodle and LV-909 were likely overpowered in .90 and earlier, but now they're pretty much useless in atmosphere or for liftoff or landing on Kerbin or anywhere else in the higher gravity range.

I'm thinking a buffed Poodle (perhaps call it the Standard Poodle) should slot somewhere between the current one and the Skipper, perhaps in the third towards the current Poodle. Could stretch its length a bit in the modded CFG and up its mass just a little.

What to do for a buffed LV-909? No solid ideas here.

For the KR-2L I'm tempted to do a straight clone of it as it was in .90. It's just silly to have an engine that's much heavier and quite bit larger than the Mainsail have so much less thrust it can barely lift itself off the pad. Try launching the stock Learstar... oh wait, you can't because Squad nerfed the main engine so much. You have to swap it out for a Mainsail to get it to move.

With the new aero, rockets don't need as much raw power to overcome drag on their way up to orbit, so making copies of the engines (except perhaps the KR-2L) equal to their pre 1.0 versions would really be overdoing it.

They seem to have adjusted the T-30 and T-45 just right.

[MatterBeam]

You cannot lengthen engines without making them wider: you have to resort to a new model.

[Galane]

Can't do the same thing as has been done with fuel tanks and other parts in ReStock? Many of them have had their lengths and diameters changed by different amounts.

[Crzyrndm]

Increase the ASL ISP if you want to "denerf" the ASL thrust of the vacuum engines on Kerbin. Alternatively, use engines suited for the job at hand (4x24-77's in place of the 909, pairs of Mk-55's in place of a poodle, SRB's/Mainsails/quad cluster for bigger stuff) instead of just using the same old engines that could do everything.

Edited May 7, 2015 by Crzyrndm

[Randazzo]

You cannot lengthen engines without making them wider: you have to resort to a new model.

Have you tried this?

I'm asking in earnest, not being a wiseguy.

You can alter the scale of other models any way you wish, you just need to correct the node positions. For engines I'd imagine the fx offset would need to be changed as well.

Edited May 7, 2015 by Randazzo

[MatterBeam]

Have you tried this?

I'm asking in earnest, not being a wiseguy.

You can alter the scale of other models any way you wish, you just need to correct the node positions. For engines I'd imagine the fx offset would need to be changed as well.

Scalefactors used for models affect all x,y,z equally.

edit:

Oh I see now. New to the 1.0 config files is a line that replaced scalefactor by scale = 1,1,1

I'm liking this 1.0 update more and more!

Edited May 7, 2015 by TruthQuark

[NathanKell]

New to 0.20 you mean.

(0.20 added MODEL node support.)

As for nerfing--the Poodle and LV-909 produce 20% more thrust than they used to, and the Poodle masses less than it did to boot. The KR-2L maintains its 2000kN max thrust. Not sure where you're seeing nerfs. Now, their sea level thrust did go down, but that only affects the first few km on Kerbin.

[MatterBeam]

New to 0.20 you mean.

(0.20 added MODEL node support.)

As for nerfing--the Poodle and LV-909 produce 20% more thrust than they used to, and the Poodle masses less than it did to boot. The KR-2L maintains its 2000kN max thrust. Not sure where you're seeing nerfs. Now, their sea level thrust did go down, but that only affects the first few km on Kerbin.

0.90 config file for a part:

// --- asset parameters ---mesh = model.mu
scale = 1.0
rescaleFactor = 1

1.0 config file for a part:

MODEL	{
		model = CryoEngines/Parts/Engine/cryoengine-125/cryoengine-125-1
		position = 0.0, 0.0, 0.0
		scale = 1,1,1
		rotation = 0, 0, 0
	}

[Galane]

Increase the ASL ISP if you want to "denerf" the ASL thrust of the vacuum engines on Kerbin. Alternatively, use engines suited for the job at hand (4x24-77's in place of the 909, pairs of Mk-55's in place of a poodle, SRB's/Mainsails/quad cluster for bigger stuff) instead of just using the same old engines that could do everything.

The problem with using clusters is the difficulty or impossibility of stacking below them.

The KR-2L used to have a sea level thrust higher than the Mainsail. It also used to have a vacuum thrust of 2500. Now it's only 1,000 ASL where the Mainsail is 1379. Shouldn't the larger engine be more powerful at all altitudes?

[MatterBeam]

The problem with using clusters is the difficulty or impossibility of stacking below them.

The KR-2L used to have a sea level thrust higher than the Mainsail. It also used to have a vacuum thrust of 2500. Now it's only 1,000 ASL where the Mainsail is 1379. Shouldn't the larger engine be more powerful at all altitudes?

Clusters should be build by placing 3/4/6 modular girder segments at the base of the fuel tank, and attach engines to the girders. I usually offset these girders into the fuel tank for aesthetic effect, have had zero overlap problems involving them so far.

For staging, add a central girder to the fuel tank's bottom attach node, a small decoupler and an aerodynamic fairing under that. Fit the fairing over the cluster and line it up with the bottom of the fuel tank.

The mainsail's nozzle is smaller than the KR-2L's. The KR-2L is more efficient in vacuum because the reaction gasses have more room to expand optimally. At sea level, however, the reaction chamber pressure to atmospheric pressure ratio is lower due to the larger nozzle surface area, so it produces less thrust.

[Crzyrndm]

The problem with using clusters is the difficulty or impossibility of stacking below them.

It's also highly unusual to need to use them as anything other than first stage engines. By the time they burn out the KR-2L already has probably 60+% of it's vacuum thrust if not more.

The KR-2L used to have a sea level thrust higher than the Mainsail. It also used to have a vacuum thrust of 2500. Now it's only 1,000 ASL where the Mainsail is 1379. Shouldn't the larger engine be more powerful at all altitudes?

Which combined with it's efficiency was absurd. Engines which are good at everything leave no place for many others. Use them for what they're intended for instead of complaining that you can't just use the same thing everywhere.

Edited May 8, 2015 by Crzyrndm

[NathanKell]

Apollo SPS:

Redstone engine (about 5ft long).

One of these had 4x the thrust of the other. Guess which.

EDIT Oh and Krakenfour, I really don't get what your post was about. Looks like...an addon part maker decided to change how models were referenced for her/his 1.0 release of the mod? Again, MODEL was introduced in .20, though Squad parts don't use it often. Did you miss all the hoopla over 'welding parts' the last two years?

Edited May 8, 2015 by NathanKell

[Galane]

Welding parts, altering the size and/or shape. Squishing, stretching, mashing... Too bad the game engine doesn't allow for differential scaling and skewing. Could take a cylindrical fuel tank and turn it into a tapered and offset adapter.

So anyway, assume the little green rocket scientists have bent their brains to the task and improved the engines that are now weaker at sea level. What would be some reasonable plausible numbers that will still fit with the new atmosphere?

Not looking for Aerojet M-1 performance where the turbopump exhaust was ducted through the edge of the nozzle skirt to contribute 120 kN of thrust to the designed 6.67 million Newton baseline thrust. 'Course an appropriately scaled M-1 would be excessively cool.

Just need a variant of the KR-2L that can do things like lift the Learstar off the pad. Odd that Squad did all these changes then left in a stock craft that doesn't just need a few adjustments to improve it, it's completely unflyable since it can't even launch.

The original KR-2L was too powerful, with the ReStock adapter to mount four of them plus four LV diameter and one Rockomax diameter engines beneath a ThunderMaximus tank... it tended to be *too much* if those other engines were T30's and a Mainsail. Efficiency was considerably worse (with the same rocket) with all those than with only four KR-2L, even with MechJeb's terminal velocity limiter. I haven't yet fixed the CFGs for those parts for 1.0.2 but I'm half expecting that the assembly would struggle to lift off now.