Controlled fuel transfer?

[manfrom]

I've built a vessel to mine fuel on Minmus and return it to a tanker in LKO. I did my mining, flew back to LKO and transferred all my fuel into a big orange tank - all fine so far. I now want to transfer a small amount back to my mining vessel, equally distributed between some radial fuel tanks (with equal amounts of fuel and oxidiser) but this seems very difficult to do. I only want to transfer enough back to get back to the surface of Minmus, but it seems fiddly to get an exact balance of fuel between tanks so that weight distribution is equal. Any tips? I'm using stock and career mode.

Ideally, I'd like to able to predetermine the amount of fuel/ox to be transferred into a specific tank...

 

Thanks!

[Snark]

1 hour ago, manfrom said:

fiddly to get an exact balance of fuel between tanks so that weight distribution is equal

This is fairly easy, if you know the secret handshake.    You can do multiple tank transfers concurrently.

Let's say you have one big orange tank full of fuel, and N smaller, identical-to-each-other tanks that are symmetrically arranged and which you need to have identical amounts of fuel in, so that you'll have an even mass distribution.

You can select as many tanks as you want (right click the first one to select, then hold down ALT while right-clicking additional tanks to select them).  Once you have selected the big orange tank and all the little ones, just click the "out" button on the big orange tank.  Presto:  propellant starts concurrently flowing into all the little tanks, symmetrically.

1 hour ago, manfrom said:

equal amounts of fuel and oxidiser

Unfortunately, this is hard, though it seems silly that that's the case.  The stock game doesn't give you any tools to do this; you just have to eyeball it.  Unless you come up with some hacky design trick, like including some small empty tank on your mining vessel that you can use as a "measuring spoon".  Fill up the little tank completely (thus guaranteeing even LF + O), then empty that tank into your target tanks.  Repeat.

1 hour ago, manfrom said:

predetermine the amount of fuel/ox to be transferred into a specific tank

^ Same problem as the "equal fuel + oxidizer" issue.  Just have to eyeball it, there's no precise way to do this in stock unless you're using a "measuring spoon".  Annoying, yes.

 

So, to summarize:

• Equal amounts in multiple tanks:  yes
• Equal LF versus O:  no
• Precise amount transferred:  no

[manfrom]

Thanks, great answer. The ability to do equal LF + Oand precise transfers would be a good development for 1.3 I guess...

 

 

[Snark]

3 hours ago, manfrom said:

The ability to do equal LF + Oand precise transfers would be a good development for 1.3 I guess...

Well, feel free to post that over in the Suggestions forum...

 

[Nicias]

I design my miner so that the required fuel to get back to the mining location is a combination of full tanks, to avoid this issue. What I would do is find one tank (or a combination of tanks) that has the required fuel capacity. Then fill them up. Then transfer fuel around to get balance.

[manfrom]

That's also a good idea -  I wish I had thought about it whilst designing my mining vessel. I will incorporate into the next one!

[Yiannis]

On 2/13/2017 at 3:14 PM, Snark said:

This is fairly easy, if you know the secret handshake.    You can do multiple tank transfers concurrently.

Let's say you have one big orange tank full of fuel, and N smaller, identical-to-each-other tanks that are symmetrically arranged and which you need to have identical amounts of fuel in, so that you'll have an even mass distribution.

You can select as many tanks as you want (right click the first one to select, then hold down ALT while right-clicking additional tanks to select them).  Once you have selected the big orange tank and all the little ones, just click the "out" button on the big orange tank.  Presto:  propellant starts concurrently flowing into all the little tanks, symmetrically.

Unfortunately, this is hard, though it seems silly that that's the case.  The stock game doesn't give you any tools to do this; you just have to eyeball it.  Unless you come up with some hacky design trick, like including some small empty tank on your mining vessel that you can use as a "measuring spoon".  Fill up the little tank completely (thus guaranteeing even LF + O), then empty that tank into your target tanks.  Repeat.

^ Same problem as the "equal fuel + oxidizer" issue.  Just have to eyeball it, there's no precise way to do this in stock unless you're using a "measuring spoon".  Annoying, yes.

 

So, to summarize:

• Equal amounts in multiple tanks:  yes
• Equal LF versus O:  no
• Precise amount transferred:  no

The little buffer tank was a brilliant thought. Thanks!