ISRU filling tanks at different rates

[Gilph]

Hi,

Have been working on a station that has an ISRU, a center orange tank, and four orange tanks that are angle snapped around the center one, directly attached and has fuel lines connected to center.  I dock with my miner lander that has ore.  The ISRU will process the ore, filling the four tanks (center is filled).  But, it will fill one tank way faster than the others (one of the four outer ones).  If all four outer tanks started with 300 each, when the ISRU is done, i will have like 500, 500, 500, 900.

I have tried creating new stations from scratch, unloading addons other than KAC and Mechjeb, and clean installs.  No addon fuel balancers. Also, other stations with similar tank setups are OK, but others are not.  Cant seem to tell the difference, other than when it fails.

Any thoughts will be greatly appreciated.

EDIT: @Kuansenhama, @genericeventhandler, thanks for your answers.

I did a test to verify that the center tank is filled, and the four outer ones were empty.  One of the four still fills up way faster.  Now that my imgur test worked, i can share pics.

Here is the test systems...a small station and a big miner:

Center tank filled, outer tanks empty (no pics for start).  Miner full of ore docks. after 3 hours:

you can see that one tank at 1500LF, all others at 391LF

@genericeventhandler, not sure if this effect is the same thing you were saying.  This will happen whether the center tank is full or not, although i dont have pics yet. It's always an outer tank.  I made this test from scratch as to not use an existing template.

Any other thoughts?

@genericeventhandler, Hi, yes, all four have fuel lines. doing some more testing, including attaching the tanks to the center using some radial attachment pieces so the tanks are not directly touching.  Will also test three surrounding tanks.

 

Edited February 23, 2016 by Gilph
respond to question

[Kuansenhama]

Not sure why this would happen. I know there was a bug with throttle and having the ISRU running. (Where 1 out of the 4 nukes on my ship would throttle back to ~15% randomly.) So it might be something similar.

I don't think the fuel lines matter if you are filling tanks with an ISRU. I think the game only uses them in the event of an engine being active.

Quick fixes might be to dump all your fuel into the center. (If you're mostly empty), Dump all your fuel into the radial tanks and keep the last little bit in the center (if you're mostly full). Remember that you can hold down the Option key. (Or whatever the 'select multiple tanks to transfer fuel' transfer key is on your OS) and select more than two tanks. This is a fast way to dump all your fuel into one tank or distribute it evenly into radial tanks.

Pics would be greatly helpful in showing us whats' up.

[genericeventhandler]

The irsu is set to stage flow priority.

ie it fills the tanks in the same order that an engine drains. The Center tank is closer to the irsu so fills faster the other tanks are further away so fill slower.

the throttle effect happens when the furthest away tank from the engine with fuel empties. The irsu is then feeding this tank that the engine is draining so reduced power. Flicking the irsu off an on  will let the engine start draining from the next tank. 

[genericeventhandler]

That is weird. Do all four tanks have fuel lines to the middle one? 

I don't play without tac fuel balancer, so I've never noticed this, I use irsu's a lot but always with inline tanks never attached radially.  

MageMage