Engine says its producing thrust, my velocity doesn't change?

[KerikBalm]

I'm trying to make a high performance engine within "reasonable" bounds.

Basically, a 30 kN plasma thruster with an ISP of 7000 seconds, that consumes 1 gigajoule per second (the reactor part that supplies this is quiete heavy...) and also consumes massless "coolant"

I made something similar back in 0.18, and I just duplicated stock parts: the 3d model of the engine was of an ion drive, and the radiators that regenerate coolant were simply the XL solar panels that didn't rotate.

Now I've decided to spice it up a bit, and downloaded the interstellar mod, (not to actually use that mod, but to use the 3d models in parts that work as I specify.

The engine (from the MPD folder for those familiar with the interstellar mod) lights up, consumes resources, and shows that thrust is being produced... but the ship doesn't move.

(btw the engine performance is weaker than that found in the Interstellar mod, less thrust, less ISP, more weight)

It seems to me this is a similar scenario to when one has a part attached directly under an engine, but I'm using the same stack attach points and such as in the mod.

Here's the relevant code:

PART

{

name = smallerMPD

module = Part

author = Fractal

mesh = model.mu

scale = 1

rescaleFactor = 1.0

node_stack_top = 0.0, 1.1615562, 0.0, 0.0, 1.0, 0.0

node_stack_bottom = 0.0, -0.1832844, 0.0, 0.0, 1.0, 0.0

fx_exhaustFlame_blue = 0.0, -0.0, 0.0, 0.0, 1.0, 0.0, running

fx_exhaustLight_blue = 0.0, -0.0, 0.0, 0.0, 0.0, 1.0, running

fx_exhaustSparks_flameout = 0.0, -0.0, 0.0, 0.0, 1.0, 0.0, flameout

TechRequired = ionPropulsion

entryCost = 14000

cost = 5700

category = Propulsion

subcategory = 0

title = Plasma Thruster

manufacturer = Ionic Protonic Electronics

description = A larger and more efficient cousin of the ion engine, it is best not to attempt to power this engine with witchcraft and instead opt for a very large electric generator.

attachRules = 1,0,1,1,0

// --- standard part parameters ---

mass = 0.75

dragModelType = default

maximum_drag = 0.2

minimum_drag = 0.2

angularDrag = 2

crashTolerance = 7

breakingForce = 200

breakingTorque = 200

maxTemp = 3600

stagingIcon = LIQUID_ENGINE

MODULE

{

name = ModuleEngines

thrustVectorTransformName = thrustTransform

exhaustDamage = False

ignitionThreshold = 0.1

minThrust = 0

maxThrust = 30

heatProduction = 300

PROPELLANT

{

name = MegaJoules

ratio = 23

}

PROPELLANT

{

name = Coolant

ratio = 2.4

}

PROPELLANT

{

name = XenonGas

ratio = 0.1

}

atmosphereCurve

{

key = 0 7000

}

}

MODULE

{

name = FXModuleAnimateThrottle

animationName = e9

dependOnEngineState = True

responseSpeed = 0.5

}

RESOURCE

{

name = Coolant

amount = 100

maxAmount = 100

}

RESOURCE

{

name = MegaJoules

amount = 20

maxAmount = 20

}

}

[tygoo7]

Did you add the thrustTransform in Unity?

[KerikBalm]

No... but that is the same thrust transform that the stock engines use...

Or is thrust transform somehow linked to the model?

The interstellar "stock" thrust transform was called "TT"

[sal_vager]

An engine needs a thrustTransform in unity or it won't work, sorry.

[MrHappyFace]

replace thrustTransform to TT, the thrustTransform is linked to the model, and if the model is from KSPI, then it should be called TT

[KerikBalm]

yes I figured that out, thanks for the replies directing me to the thrust transform problem, I didn't think that it would be linked to the model, but when I had time, I tried it that way, it worked...

Mt Happy face, how familiar are you with KSPI? I now want to use their heat radiator models and animations, but I don't want to use the entire plugin.*

I was thinking about starting a thread about how I can eploy the panels, but not retract them... but maybe PMs would be better?

As mentioned earlier... I think a lot of the stuff in there is a bit too good. While I appreciate the complexity and the attention to physics, it is a bit overly complicated for a game, and I am content to work with generic resources like "liquid fuel" (I'm thinking of renaming Xenon gas to inert gas or reaction mass)