[Closed, but further Discussion? ] My custom fuel tank is too heavy? Help?

[AcesDwn]

I apologize if this is in the wrong place, but all the other threads are very similar to creating mods..

I've created a fuel tank in Blender, imported it to Unity, and wrote it out.

I then copied it and a .cfg file into KSP SUCCESS! It shows up, attaches as expected and It was great!

Except it won't fly... Hmmm...

It's a VERY basic cylinder.. 1.25m dia, 4m deep. Holds Lf+Ox (900/1010) respectively..

However, the basic 1 kerbal capsule, then the tank, then a mainsail.. It falls back to the launchpad and explodes.

Added 4 of the larger SRB's to help it, but even with that it only climbs at a MAX of 1.1m/s....

I think I have something off in the .cfg, but is there somewhere else I should be looking too?

Thanks!

Edited October 4, 2015 by AcesDwn
Closed, but not answered....

[martinezfg11]

Post a copy of your .cfg

[AcesDwn]

I've been playing with the values, but here is what it is all set at now.

Thank you!

-------------- Copy of .cfg Contents --------------------------------------------------------

PART

{

name = md40FuelTank

module = Part

author = AcesDwn

mesh = model.mu

rescaleFactor = 1.25

node_stack_top = 0.0, 2, 0.0, 0.0, 1.0, 0.0, 2

node_stack_bottom = 0.0, -2, 0.0, 0.0, -1.0, 0.0, 2

node_attach = 0.1, 0.0, 0.0, 2.0, 0.0, 0.0

TechRequired = basicRocketry

entryCost = 1200

cost = 150

category = FuelTank

subcategory = 0

title = MD-40 Fuel Tank

manufacturer = Joe's Exploding Parts LLC.

description = The MD-40 is a new product developed in 1 day. Could be prone to SPECTACULAR explosion! (But who doesn't like that, right? :-p )

attachRules = 1,1,1,1,0

mass = 2

dragModelType = default

maximum_drag = 0.2

minimum_drag = 0.3

angularDrag = 2

crashTolerance = 6

maxTemp = 2000 // = 2900

breakingForce = 200

breakingTorque = 200

bulkheadProfiles = size2, srf

RESOURCE

{

name = LiquidFuel

amount = 900

maxAmount = 900

}

RESOURCE

{

name = Oxidizer

amount = 1010

maxAmount = 1010

}

}

-------- End Copy ------------------------

[AcesDwn]

Update For those thinking of this issue to try to help.

I've noticed that the tank isn't too heavy (I think).. The main engine ignites, but flames out after about 1/2 to 1 second and no longer burns...

Throttle drops to zero as well, as if it's out of fuel, but it isn't..

Still thinking something in the .cfg, but I don't know enough about it (yet) to know for sure...

Thanks!

[AcesDwn]

One final update for today. (I'm done troubleshooting for now. Need sleep lol)

Seems that "Electric Charge" is not flowing through my custom fuel tank. I've tried a few different engines on my tank all with the same result.

Engine Electric goes to 0 and it shuts off. (Even though there is 1k electric in the battery on top of the tank.)

To confirm this, I replaced my tank with a stock tank (Same parts otherwise). Electric was fine, didn't drop to 0, and launch was as expected.

I'm going to keep trying things tomorrow, but if this helps jog any memories out there of "OH Yeah! I had that once!" I'd appreciate any insight or links to the proper direction to be looking for my solution. (Doesn't have to be handed to me, but directions on WHERE to look would be appreciated.. lol)

Thanks again!

[AcesDwn]

Well, I feel like an idiot.. The electric on the engine was it's generator output. not charge.. Anyway, I still don't know why the tank didn't work, but I made another smaller one similar to the FL-T800 and that worked just fine...

[AcesDwn]

I still don't know why this happened, so it's an open question....

However, I have since created a fuel tank and a capsule that both work.

I don't want to mark this as answered because it really wasn't answered.

It could be a good thread for others that experience the same...

Aces

[Randazzo]

Aside from the strange fuel ratio (should be 900/1100), I don't see anything wrong in the cfg file.

More information will be needed to figure out what happened, perhaps screenshots of it happening in game? Though I strongly suspect your mainsail is just burning through all the fuel. That's a big engine for a tiny pod and fuel tank.

Edited October 5, 2015 by Randazzo

[AcesDwn]

As usual, you're right on top of it Randazzo..

I honestley have no idea what happened.. I actually deleted the folder from GameData, but when you asked for screenshots, I put it back in.

Go figure.. It worked right.. (I have no idea..) Maybe a glitch when I first tried? It was, after all, my first attempt ever and have since made 2 tanks and a capsule.

Oh, Made my first engine too.. Nothing I'd share, but the basic shape and it worked..

I have a lot of learning left to go...

I guess that if others have this same issue, remove the "GameData/<your folder>/<your part name>" folder and try copying again?

I tried to re-create the issue, but it didn't happen. It just worked as expected.. (Even with the odd ratio..)

By the way.. I did some math.. I read the ratio was 1.67 (ish) ... I found that if I take the LF and then multiply by 1.223, that typically gets the proper amount of Oxidizer needed.. Am I off on that?

Thanks again!!

[Randazzo]

The LF/O ratio is always 0.9 to 1.1. Multiplying by 1.223 will get you close, multiplying by 1.222222222222222222... will get you closer, but it's an easy enough ratio.

If you want to do maths for it, divide the amount of LF by .9 and multiply the resulting number by 1.1 and you have your O amount.

[AcesDwn]

Yup!

I kept adding "2's" to my math and it kept getting closer.. After 8, I decided I'd round up and call it close.. (For KSP.. Never for real life.)

Divide by .9, then multiply by 1.1 sounds a LOT better.. LOL

[NecroBones]

Something I'll sometimes do too, is to use a stock tank as the basis for one of my new tanks. For instance, I may be making a 1.25m tank that is twice the length of the FL-T800. In that case, I'll take the numbers (LF, Ox, mass, cost, etc) from that tank and just double them. It saves you from having to think too hard.

This method works great for all sorts of tanks too. For instance, if you're making a fueled size adapter, you can quickly calculate the volume of a truncated cone (there are online calculators to make this simple) and compare it to the volume of one of the stock tanks, and then use that as the multiplier.