Easy way of creating custom fuel tanks.

[RedeyePete]

I decided that I wanted to create some round bodied fuel only tanks for use with nukes. It makes attaching multiple radial parts (eg 6 tanks) easier.

Rather than installing and learning some 3d grafics program, I went the easy way and modded the existing Kerbodyne size 3 tanks (and the size 4 ones from the expansion pack)  to be fuel only.
For this, all you need is a simple text editor (I used Notepad++) and MS paint to create a PNG file. Oh and Excel would help.

Here's what to do:
Locate the KSP parts directory -
.....\Kerbal Space Program\GameData\Squad\Parts\FuelTank\Size3Tanks
Copy all but one file into a new diectory where you will keep your modded parts -
.......\Kerbal Space Program\GameData\RedsMods\Parts\FuelTank
I created and put mine in directory "RedsMods\Parts\FuelTank" but you can create your own name.
Just make sure you put it in the GameData directory. I copied all the files shown below except for fuelTanks_cm.dds
This is the old texture file that we will replace with the PNG file. However, make note of the file name as we will be using it later.

Open one of the CFG files in a text editor. Eg - large.cfg
Change the "name" to something you like. I also changed a few other things which were not importatnt.
The "Title" and "Description" will show up in the VAB
The Model - "mode1 " needs to point to the appropriate ".mu" file located in your new directory
I deleted the whole Oxidizer section in Resource and added that amount to the Liquid Fuel section.

This is what the Resource section looked like originally:

 

Now for the graphics.
In Excel I created a grid starting with A1 and ending in the bottom Right had side with AF102. (Doesn't have to be exacly that number), and pasted it into a PNG file created in MS Paint (or whatever graphics program you like)

I saved this file in my new dirctory and called it EXACTLY the same name as the old DDS file except it was now a PNG file:
.......\Kerbal Space Program\GameData\RedsMods\Parts\FuelTank\fueltTanks_cm.png
If you were to look at the bottom of the ".mu" file in a text editor you will see that it is referencing "fueltTanks_cm"
Now go into KSP and look at the tank in the VAB

This will show you what part of the PNG file a particular section is looking at.
Paint by numbers!
Note that the Top, Bottom and some of the small parts use the same area for all 3 different size tanks. The sides generally use different areas.
This is what I ended up with after doing all 3 size tanks:

Save this new file and replace the temporary Excel grid file:
.......\Kerbal Space Program\GameData\RedsMods\Parts\FuelTank\fueltTanks_cm.png

Restart KSP and you will have some nice new shiny tanks.
The same process should work for other parts as well.
Below is a pic of all the tanks I did. 1st is mine, then the original, mine, original......

 

Edited October 13, 2018 by RedeyePete
Typo