Fuel pickup systems

[ibanix]

I'm having a lot of trouble designing a system that will let me land, dock, and collect fuel from my mining bases. The alignment on the Clamp-O-Trons has to be precise, or they won't dock, and once you're landed and on wheels it is (apparently) impossible to adjust height.

What methods has anyone developed for a stress-free pickup from a fuel base?

[kujuman]

If you're willing to install and use mods, the go-to mod is Kerbal Attachment System, which will allow you to attach two vessels together using a variety of parts. There are a few other mods that just do fuel transfer over short distances, but I am unfamiliar with them.

http://forum.kerbalspaceprogram.com/threads/92514-1-0-4-Kerbal-Attachment-System-%28KAS%29-0-5-4

In a stock KSP install, one option is to use the Advanced Grabbing Unit (the claw)...it will also make two vessels into one, but there are some bugs with it still that may destroy your vessels.

[Xavven]

Firstly, use the claw instead of docking ports. Secondly, I usually have a fuel truck with said claw mounted to the front of it whose sole purpose is to pick up fuel from the refinery and drive over to whatever vessel has landed nearby. I can get close (easily within 100 meters) but you'd be wasting a lot of fuel trying to land right on top of the refinery, or lugging around wheels into orbit and back.

[Superfluous J]

I personally prefer to land a fuel lifter directly onto a Sr. docking port on the surface. It takes a very steady hand and a good amount of practice to get down, but it feels awesome to nail it and even better to realize you're actually comfortable with it.

Another option is a claw-enabled car or hover-tug. Claw it onto the refinery, fill up, claw to the lifter ship, fill it up, and then head into space. I suggest if you go this route to use the Stock Bug Fixes mod.

Speaking of mods, a lot of people (myself included) have used Kerbal Attachment System to hook everything up. I've not used it since Kerbal Inventory System came out so I can't really speak on its current implementation, but back in the day it was - in my mind - THE way to do ISRU bases.

And the final option is the simplest: Lift the whole ISRU refinery off the surface and into space. It's not the most efficient and you gotta land it again to be useful, but hey it's the simplest method, so it's not expected to be the most efficient.

[ibanix]

I didn't realize the Klaw allowed that; it has 'No Fuel Crossfeed' in the description. Now I've got some ideas, thanks!

[Alshain]

I didn't realize the Klaw allowed that; it has 'No Fuel Crossfeed' in the description. Now I've got some ideas, thanks!

Fuel Crossfeed is not the same thing as Fuel Transfer. Fuel can be transferred across any connected part. Fuel crossfeed is the priority in which active engines can drain a tank. If a tank is not in the same crossfeed grouping as the engine, the engine can't use that fuel (unless you transfer it manually to a tank in the crossfeed group). Fuel crossfeed rules are what keep your ascent stage from draining fuel from the upper stage, since decouplers and separators all have the "No Crossfeed" tag. Docking ports allow you to choose to crossfeed or not, and Jet Engines and RCS ignore crossfeed rules and do it anyway.

Edited September 23, 2015 by Alshain

[The_Rocketeer]

'Crossfeed' just means engines can draw fuel from beyond this part, 'no crossfeed' means they can't. Manually transfering fuel, like you'll be doing, will go from any tank to any tank on the same ship or docked/klaw'd complex.

[FlyingPete]

When you're using the claw for surface docking, make sure you're controlling the claw-equipped vessel/vehicle. Not tried it in 1.0, but in earlier versions, docking with the other ship caused the planet's surface to disappear and bad things then happen.

[Cairol]

Not tried it in 1.0, but in earlier versions, docking with the other ship caused the planet's surface to disappear and bad things then happen.

So if the planets surface disappears, it's not a bad thing to begin with? XD

We KSP players are surely used to a lot.

I've never tried it myself, but I would also suggest to control the claw vehicle. Just to avoid the Kraken...

Personally, I use KAS for transferring fuel.

Only disadvantage of that solution over the fuel-truck-with-claw thing is: You need to land more precisely, because the connection tubes have limited range.

A truck can drive a couple of hundred meters if necessary.

[Clipperride]

As others suggest, the Claw is one way to go. Here's my current version -

[Slam_Jones]

May have been mentioned, but I've been consistently using KAS (Kerbal Attachment System) for a while, and it makes things very stress-free. The ability to place connector ports anywhere on your vessels, and connect them via a Kerbal on EVA, is invaluable. No need for precision docking... just get it close enough and link it up. Then, simply unlink when ready to depart.

At least it works for me.

This is from back in 0.90 or earlier, but you can see the pipe and one of the connector ports. Same idea, but a drill attached to a large fuel tank with boosters strapped to the side.

[Wjolcz]

Go grab KAS. It will save you a lot of hassle.

It also should be stock. At least the basic stuff like fuel hoses.

[Clipperride]

I agree Veeltech, some sort of stock EVA link up should be included some day.