Questions before building my first real Deathmobile

[Thwap]

Okay so I’ve got access to a couple crashed APCs to cut up for parts, lots of equipment, lots of batteries, and a safe place to work. Time to quit squatting in this fire station and take on the world. But I do have some questions.

1. I notice that the standard APC only has armor on the exterior tiles. Is there any reason to armor interior tiles of my deathmobile or is that just pointless weight?

2. Similarly, should I use heavy duty frames only on exterior tiles or for all locations? Using standard frames for the interior would save some weight.

EDIT: Oh yeah, multiple batteries? Multiple gas tanks?

[Coolthulhu]

Collisions propagate quite far from the original collision point. Plating all important areas isn’t a bad idea (but don’t use hard plating there - it’s too heavy). Also, flowers and shrubs only collide with wheels and that collision can also propagate up and damage your solars/craft rigs that share a tile with the wheel.

Frames are less important because they’re already quite resistant. A destroyed frame is also cheap to replace, unlike other parts it can share the tile with.

Multiple batteries are a must if you intend to seriously use electric engines.
Multiple gas tanks are only necessary when your car gets huge. Keep them away from danger though - gas tanks explode really hard when shot.
Both batteries and tanks are rather easy to acquire and not that heavy, so you probably can afford to add more of them.

[Thwap]

Awesome, thanks for the answers.

Are electric motors really viable? I’d be more than happy to sacrifice some performance to get out of having to siphon gas, but I’m under the impression that solar is nerfed to oblivion.

[KA101]

Large electric motors (scrap tankbots!) are OK for smaller vehicles but don’t have the power of a good gas engine. Regular ones are good for a golf cart and the smaller ones shouldn’t be used for vehicles.

If you plan on running things over with your road rollers, you’d do well to use heavy-duty frames, etc on them. Roller drums are tougher than conventional frames.

And gas tank detonations are no joke. A full external tank has a larger blast radius than a mininuke.

[i2amroy]

And gas tank detonations are no joke. A full external tank has a larger blast radius than a mininuke.

Which really should be fixed at some point.

[EkarusRyndren]

[quote=“KA101, post:4, topic:7580”]And gas tank detonations are no joke. A full external tank has a larger blast radius than a mininuke.

Which really should be fixed at some point. :P[/quote]

[size=18pt]It’s not a bug, it’s a feature.[/size]

As someone who regularly uses large-ass vehicles, just let me say something:
If it’s bigger than a bus you probably can’t run it on electric engines. You’ll note I’ve got electric engines in the RMCC but that’s mostly so I can try (desperately) to crawl to a gas station at 15 MPH rather than walk. It’s also worth mentioning that 1 V12 is better than 2 V6s

Also, vehicle turrets sound cool and useful but to my knowledge they still shoot their way through your hull to kill a rabbit on the other side it spotted.

Lastly, mind what you hit with your vehicle, headlights are stupidly fragile.

[NoobKid]

[quote=“i2amroy, post:5, topic:7580”][quote=“KA101, post:4, topic:7580”]And gas tank detonations are no joke. A full external tank has a larger blast radius than a mininuke.

Which really should be fixed at some point. :P[/quote]

[size=18pt]It’s not a bug, it’s a feature.[/size]

As someone who regularly uses large-ass vehicles, just let me say something:
If it’s bigger than a bus you probably can’t run it on electric engines. You’ll note I’ve got electric engines in the RMCC but that’s mostly so I can try (desperately) to crawl to a gas station at 15 MPH rather than walk. It’s also worth mentioning that 1 V12 is better than 2 V6s

Also, vehicle turrets sound cool and useful but to my knowledge they still shoot their way through your hull to kill a rabbit on the other side it spotted.

Lastly, mind what you hit with your vehicle, headlights are stupidly fragile.[/quote]
Even if they’re inside the vehicle?

[jcd]

I always play full solar. but i am not making too big trucks. Just enough to store a little of everything i might ever need for crafting plus food for 1-2 (31-day) seasons, spare parts for fixing the vehicle or making a light lootmobile and lots of clothes & tools…

2 large electric engines suffice to move 15 tonnes with ~100-120 kph, and for me thats enough.
i never have a heavier vehicle or need to go faster… ( sure, i’d prefer reaching around 180 kph, but i don’t really need to, and being self-sufficient is my goal, as is avoiding gas tank explosions)

Certainly stupid amounts of storage batteries + truck batteries + upgraded solar panels are needed to be always online without fear of ever running out, but batteries are very easy to get/craft and for solars, i always start with normal ones, and replace them when possible.
The space on a truck roof is enough, without needing to also use the external tiles for solars/batteries.

For hd-frames/plating, i suggest starting from the outside, and if you got enough resourses extend everywhere. Avoid using hard steel inside though. (if you got enough HD frames, it pays to make vehicle from scratch with those.)

edit:
putting headlights inside the vehicle is what i do too… they don’t need replacements in this case

[TheFlame52]

[quote=“EkarusRyndren, post:6, topic:7580”]As someone who regularly uses large-ass vehicles, just let me say something:
If it’s bigger than a bus you probably can’t run it on electric engines. You’ll note I’ve got electric engines in the RMCC but that’s mostly so I can try (desperately) to crawl to a gas station at 15 MPH rather than walk. It’s also worth mentioning that 1 V12 is better than 2 V6s[/quote]
The Solar Roller VI (which is quite a lot bigger than a bus) runs on three large electric engines. It gets good speed, but keep in mind that I have 9 quantum solar panels and I still have power troubles.

[Weyrling]

My method of recharging storage batteries to power large electric motors is to first transport gas to my static base. Once at my base I dump the gas in an immobile ‘vehicle’ covered in vehicle crafting stations, solar panels, a bed, windows, security turrets, etc. It also has several gas motors with alternators and a frame filled with storage batteries (which I swap out manually to my vehicle).
Once I turn the motors on I generally take a nap because AFAIK you still have to be nearby for them to charge, but running the motors while you’re sleeping should generate more than enough power to run 3 large electric motors for a day.
I still have a bunch of solar panels, but with a driver like me they’re better off sitting on a static frame than attached to my Deathmobile…

One thing that’s good to know is that you can use a muffler for each engine, with ‘medium’ electric motors you can have a nearly silent loot mobile that can carry a few tons of loot faster than any enemy can run, unfortunately it will take entire minutes to get up to speed, making it a worse getaway vehicle than literally dragging a motorcycle/car behind you in the short run (On the plus side, anybody that isn’t messing with Granades can’t carry 3 tons of loot without breaking their spine).

As a slightly relevant side question, does anybody know what the most efficient motor for turning gas->electricity is? I’ve been using whatever I pick up but there’s probably something that’s less terrible at it than V6 engines.

[TheFlame52]

Try the smallest on you can find, then stick all three types of alternator on it.

[Coolthulhu]

I can’t find how wasteful idle engines are, other than the lower cap of 1% of max fuel consumption.
Bigger gas engines are significantly louder than smaller ones regardless of speed, but are they actually more wasteful when powering just the alternators?

[TheWumpus]

[quote=“Coolthulhu, post:12, topic:7580”]I can’t find how wasteful idle engines are, other than the lower cap of 1% of max fuel consumption.
Bigger gas engines are significantly louder than smaller ones regardless of speed, but are they actually more wasteful when powering just the alternators?[/quote]

I’m…still not sure. I just did some !!SCIENCE!! with the !!SCIENCE!! Dorf (throw away testing characters who die horribly as soon as their purpose is done) and it turns out that the larger engines display more fuel consumption but the test results indicate at idle might suggest otherwise. How so? I crafted 7 different stands, one for each engine type. I put all three alternators on each, along with a storage battery, and a single regular gas tank. Each got 2 plastic bottles (800 total units) of gasoline. Each battery got primed with 700 total charges of pocket batteries.

Gentlemen, start your engines!

Wait six hours. Note, do not do this in a basement, unless you like smoke. Since the Dorf had to survive to view the results he got a mask.

Check all stands:
All stands had between 41-43% charge on the battery, probably due to the order I turned them on and off.
All stands had, from 2% fuel, 0%.
The basement was completely full of thick smoke.

The main thing I’m seeing is despite the fuel consumption differences (the v12 for example showing 10 fuel consumption compared to the single cylinder’s 1) the engines all ran for the same length of time and achieved the same amount of work (IE charge). You would expect an engine with 10x the fuel consumption to shut down long before the little one cylinder (note: the small single cylinder and the regular single cylinder both had 1 fuel consumption, but the small does not appear to require any battery charge to start). Instead, they all just kept running those alternators.

So…inconclusive pending further study? Maybe from a full tank of fuel? Or maybe size doesn’t matter on a stand mounted generator.

I personally enjoy the thought of powering my mini-fridge with a v-8.

[Thwap]

Is installing multiple alternators a thing I should do with the deathwagon? And is there a concise list anywhere of what can go in the same squares as what? I’d hate to find out the hard way that I can’t have X on the same spot as Y and have to change everything around.

Oh yeah, and how much does order of installation matter? Like okay, say you have an aisle, a roof, a solar panel, and an armor plate. What order ought they be installed in? I’d hate to bolt armor plates over my solar panels like an idiot and then drive around wondering why they don’t work.

Lots of questions, I know, but this is one hell of a system.

[Coolthulhu]

!!SCIENCE!!

Fuel consumption is describes proportions of fuel consumption at max usage, not idle consumption. Fuel usage depends on load - in your case just the alternators.
While your results aren’t exactly a conclusive proof, they suggest that there is no difference in efficiency between engines, or that the difference is small.
It should also mean that idle engine with alternators only powers the alternators - no fuel is wasted, all goes directly to power.

This means one important thing: If you want fuel efficiency, DON’T use car and motorbike alternators in your generator. Those have lower efficiency than truck alternator.
I’m going to test it right now.

[edm]

[quote=“TheWumpus, post:13, topic:7580”]!!SCIENCE!!

Fuel consumption is describes proportions of fuel consumption at max usage, not idle consumption. Fuel usage depends on load - in your case just the alternators.
While your results aren’t exactly a conclusive proof, they suggest that there is no difference in efficiency between engines, or that the difference is small.
It should also mean that idle engine with alternators only powers the alternators - no fuel is wasted, all goes directly to power.

This means one important thing: If you want fuel efficiency, DON’T use car and motorbike alternators in your generator. Those have lower efficiency than truck alternator.
I’m going to test it right now.[/quote]

So installing all three alternators to a 2-stroke 1 cylinder engine (my current setup) would generate less power per unit of fuel than having just the truck alternator?

[Coolthulhu]

Test finished.
3 setups: 1 just truck alternator, 1 car+truck and 1 motorbike+car+truck. All had 1000 units of gasoline and a 0.74 liter 1-cylinder engine.

Just truck alternator charged storage battery to 61%
Truck+car to 58%
Truck+car+bike to 54%

Differences aren’t great, but it clearly shows that just truck alternator is the way to go if you want efficiency.

[jcd]

what about truck vs car vs motorbike alternators ojn their own? are we certain that different alternators have different efficiencies?

[Coolthulhu]

Yes.
https://github.com/CleverRaven/Cataclysm-DDA/blob/master/data/json/vehicle_parts.json
Ctrl+f "alternator"
power is how much kinetic energy it generates, but it’s negative, so it actually represents how much it strains the engine. epower is how much electric power it produces at 100% durability.

Simple division shows that truck alternator is the most efficient one.
I actually tested it before making the proper multi-alternator test (because I forgot what I was doing and set things up improperly) and empirical results confirm predictions.

[edm]

[quote=“Coolthulhu, post:17, topic:7580”]Test finished.
3 setups: 1 just truck alternator, 1 car+truck and 1 motorbike+car+truck. All had 1000 units of gasoline and a 0.74 liter 1-cylinder engine.

Just truck alternator charged storage battery to 61%
Truck+car to 58%
Truck+car+bike to 54%

Differences aren’t great, but it clearly shows that just truck alternator is the way to go if you want efficiency.[/quote]

I started testing it out before waiting for an answer, my results were similar:
0.37L 1-cyl Engine
Starting out with 400 units of fuel and 100 charges in the battery.
Truck+car+motorbike alternators resulted in 23032 charges on the battery.
With just the truck alternator, the generator rig produced 24850 charges.

So there we have it.