Rover Ore Miner/Refinery Help

[sardia]

What's the proper ratio of drills to refinery to fuel cell arrays so that's optimal for this craft? It only works when I time accelerate at 3% ore concentration so I was surprised. Should I add more drills?
[IMG]http://i.imgur.com/44hEGGR.jpg[/IMG] Edited November 25, 2015 by sardia

[TronX33]

I'm pretty sure you need an ore tank. Run the drills, collect the ore, [I]then [/I]run the converter. With that many drills, you need a lot of radiators too, and a lot of power generation.

[sardia]

There's an radial ore tank and a radiator.

[Arugela]

You won't need alot of radiators or any at all... You need more electricity. and if you run the converter and Drills with a small amount of ore you can run it in fast forward pretty easily. It takes more than 8 drllls to get enough per second to feed one converter correctly. So you may have a lot of wiggle room. Just use a single 75 ore container and see if it's enough. And you won't use full electricity if you can't convert the full amount. It will scale with the available ore from my experience. I just stack a bunch of generatros somewhere in groups of 8. You's be surprised how little it uses in practice. you may not even use up stored electricity at all. Edited November 22, 2015 by Arugela

[sdrevik]

I didn't see a docking port or a claw- how are you going to transfer the results?

[sardia]

[quote name='Arugela']You won't need alot of radiators or any at all... You need more electricity. and if you run the converter and Drills with a small amount of ore you can run it in fast forward pretty easily. It takes more than 8 drllls to get enough per second to feed one converter correctly. So you may have a lot of wiggle room. Just use a single 75 ore container and see if it's enough. And you won't use full electricity if you can't convert the full amount. It will scale with the available ore from my experience. I just stack a bunch of generatros somewhere in groups of 8. You's be surprised how little it uses in practice. you may not even use up stored electricity at all.[/QUOTE]
There's 8 fuel cell arrays lining the bottom of the rover.

There's a docking port spot open behind the refinery. I also have KIS/KAS if needed.

Edit: Wait, it's 8 to 1? I have 14 drills here, why does my ore level not increase? Are you assuming an ore percentage or a high level engineer? Edited November 23, 2015 by sardia

[sardia]

This is the Mk2 version, with Junior drills.
[url]http://i.imgur.com/ZWHuINm.jpg[/url][IMG]http://i.imgur.com/ZWHuINm.jpg[/IMG]

Somehow, this one is half as efficient despite having almost twice the drills. Is the wiki wrong about the ore/second rate? It takes 5 days vs 2 days going 2 marks from max time warp to fill up my tanks. On the plus side, it uses 7k less rocket parts. Any idea why?

[Geschosskopf]

[quote name='sardia']What's the proper ratio of drills to refinery to fuel cell arrays so that's optimal for this craft? It only works when I time accelerate at 3% ore concentration so I was surprised. Should I add more drills?][/QUOTE]

Um, 14 drills?!?!?!?!?!? Why on Kerbin would you do that? One drill will fill any amount of tankage just as surely as 2 or a dozen, with way less mass to get out there so is way cheaper to move, has a lower part count, and produces way less heat while consuming way less power (both of which require more parts and an even bigger lifter). The only thing 1 drill costs more of is gametime, which is never an issue unless you use life support, and a few days isn't much of an issue even then.

There are several key facts to keep in mind when designing any ore system:

1. If you're drilling and refining with the same vessel, you only need 1 of the smallest ore tanks. This is because you're drilling and refining simultaneously, so basically the ore goes straight into finished product without needing to stockpile any. So all your tankage (except for 1 small radial ore tank) should be for finished product. You only need mondo ore tankage if you're drilling with 1 vessel and refining in another.

2. The ore production rate of drills and the ore consumption rate of the ISRU don't quite balance. With all parts the same size, 2 drills will produce ore slightly faster than 1 ISRU can consume it if making LFO, but the ISRU is slightly faster than 2 drills when making either LF or O individually. The difference either way is less than the output of 1 drill, so there's no point in having more than 2 drills per ISRU.

3. The only thing you gain from having more than 1 ISRU + 2 drills per ship is less gametime to complete the job. Which is nothing to you personally if you use warp, and doesn't matter enough to bother with in game terms like missing transfer windows and consuming life support. OTOH, the more ore parts you have, the more power you need, the more cooling you need, the bigger the rocket you need to get it all somewhere, and the more it all costs.

So, for the big parts, 1 ISRU + 2 drills requires 60 EC/sec and (IIRC) 400kW cooling. The 6-pack fuel cell makes 18 EC/sec so you need 4 of them to keep this running. And either 8 small or 2 medium retractable radiators to keep everything cool. For each set of 2 drills + 1 ISRU you add, you need the same amount of power and cooling.

[sardia]

Are you assuming a level 3 engineer because the 4 drills certainly isn't enough to keep up with a ISRU.

[fourfa]

[quote name='Geschosskopf']
2. The ore production rate of drills and the ore consumption rate of the ISRU don't quite balance. With all parts the same size, 2 drills will produce ore slightly faster than 1 ISRU can consume it if making LFO, but the ISRU is slightly faster than 2 drills when making either LF or O individually. The difference either way is less than the output of 1 drill, so there's no point in having more than 2 drills per ISRU.
[/QUOTE]

Yeah, this is based on the max numbers in the VAB info screens, right? It is true when you're parked over a 100% ore patch (which a lucky asteroid might be close to). A rich landing site chosen from the M700 orbital survey map may be lucky to be 10%. Then engineer skill also modifies it (as do thermal effects, in 1.0.5).

In practice, on my usual 9.51% patch on Mimmus with a level 3 engineer (likely to be true around the time you unlock ISRU), six drills is about the same output as one large ISRU. Regardless, I agree with you 100% on the rest. Making the payload lighter is much cheaper all things considered, than a bit of extra time on high warp. I haven't played with life support, but I'd think that a few days more snacks have to be much, much lighter than even a single drill.

back to the OP: are you staffing that ship with an engineer? 3% is pretty low, are you sure you can't find a better spot? Did you do a survey first or just land it wherever? And with that many drills consuming power, causing your fuel cells to consume your LF/O output, I'm not surprised you're barely breaking even. When you right click on the ISRU and drills, what does it say? In 1.0.5 you need to pay close attention to thermal effects, and maybe heat isn't really conducting to that giant radiator? Edited November 24, 2015 by fourfa

[sardia]

3% is what's on the runway. 6% is just outside KSC but I'm just testing it for now.
All rover versions have radiators and gigantic solar panels, they still barely make any fuel without time warp. I have a basic engineer that I hired. All my actual kerbals are on a mother ship headed to Mars. They're going to assemble the rover there with kis and extras planetary launchpads.
Heat management is great with the large radiator, and OK with the mid sized one. 95-90% efficiency. The isru always ramps up to 100% despite requiring twice the heat of the drills.

On a phone. Will post the mk 3 rover when I get home.

[sardia]

The Mk3. I cut it down to 4 jr Drills and 1 fuel array. It's probably not realistic since the it's on Minmus and they don't lose solar power there. Still, it takes a ridiculously long time, 10 days just to fill up.

Edit: Will up to 6 drills, and hope the engineer + timewarp takes care of the rest. Now I just need to figure out how to launch it or 7000 rocket parts...twice. (For the metal ore rover)[IMG]http://i.imgur.com/BJiUVWZ.jpg[/IMG] Edited November 25, 2015 by sardia

[Geschosskopf]

[quote name='fourfa']Yeah, this is based on the max numbers in the VAB info screens, right? It is true when you're parked over a 100% ore patch (which a lucky asteroid might be close to). A rich landing site chosen from the M700 orbital survey map may be lucky to be 10%. Then engineer skill also modifies it (as do thermal effects, in 1.0.5).[/quote]

Yeah, drill production is affected by ore concentration but ISRU is not. It is thus possible, in middling-poor ore, for 1 ISRU always to outstrip 2 drills. But even so, it's never worth the money to have more than 2 drills and just 1 drill is perfectly adequate. Time is no issue to the player thanks to warping, and even with 1 drill you still complete the job in a few days at most, which is of no consequence to the Kerbals, either.

[quote name='sardia']The Mk3. I cut it down to 4 jr Drills and 1 fuel array. It's probably not realistic since the it's on Minmus and they don't lose solar power there. Still, it takes a ridiculously long time, 10 days just to fill up.

Edit: Will up to 6 drills, and hope the engineer + timewarp takes care of the rest. Now I just need to figure out how to launch it or 7000 rocket parts...twice. (For the metal ore rover)[url]http://i.imgur.com/BJiUVWZ.jpg[/url][/QUOTE]

Turning ore into a useful amount of fuel is a process that a day or more, even on good ore, even with a good engineer. It's that way by design. Just accept it, use no more than 2 drills, and timewarp your way through it. Then the miner will be smaller, lighter, and cheaper, and need will need smaller, cheaper lifter.

Also, never use mini drills and mini ISRU unless your ship is a tiny probe refueling itself (IOW, a very low-volume operation). The mini parts consume the same amount of power as the big ones but produce at only 1/2 the rate, so they take twice as long to do the same job as the big ones.

[Mastikator]

[quote name='Geschosskopf']Yeah, drill production is affected by ore concentration but ISRU is not. It is thus possible, in middling-poor ore, for 1 ISRU always to outstrip 2 drills. But even so, it's never worth the money to have more than 2 drills and just 1 drill is perfectly adequate. Time is no issue to the player thanks to warping, and even with 1 drill you still complete the job in a few days at most, which is of no consequence to the Kerbals, either.[/QUOTE]

If you're refueling a heavy interplanetary rocket that requires dozens of tons of fuel might miss the time window of transferring. Sure you could just time warp an entire year but that's kinda annoying. It would take a LONG time to refuel an entire S3-14400 tank with just 1 drill.

[sardia]

I think he's referring to the ISRU, the drills work at the same rate, but the mini drills require less electricty and weigh less. The only reason not to use them is if you only have ore at less than 2.5%. And if I can get 4 jr drills in, you rather have 1 drill instead? I think you're abusing timewarp a bit too much.

[COLOR="silver"][SIZE=1]- - - Updated - - -[/SIZE][/COLOR]

Success. The mk3.2 works with a level 2 engineer and 6 drills. This fills up the tank in less than 15 hours at 9%. Now I just need to get the Kerbal remote xp gain mod working, and my planetary grand tour will be all set to go.

[sardia]

Follow up question, how can I adjust the design so the rover can lift off and land with stability? Or should I send another ship to come pick up the fuel?

[Octa]

[quote name='sardia']Follow up question, how can I adjust the design so the rover can lift off and land with stability? Or should I send another ship to come pick up the fuel?[/QUOTE]

Afaik, ore is lighter than the fuel you generate of it. If you have an ISRU in space, use that and get only the ore up. If not, i guess a separate vessel for resource transport (may it be ore or fuel) would still be better. This ship could be a few tons lighter, because the rover (the all in one solution) would have to lift and land many unnecessary parts: Radiators, ISRU, Drills, wheels, fuel cells. All stuff you'd carry with you but you don't need when you want to transfer fuel.