damerell

Not to be a nuisance, he says, being a nuisance, but I submit it should be adjustable on the fly. A user might (say) go between a solar and a battery powered vehicle and want correct behaviour from both. I'm wondering if I want to attempt a Campaign for Real Electric Charge mod. :-/

This is exactly what I proposed.

It'll equally be a "magic number that makes things right" however it is expressed, and it's not "a fudge factor for the differences in handling between mechanical energy and electrical energy in KSP" because stock KSP never says how much a unit of EC is. It seems better to potentially disagree with some other mods (and after all, the user has the option of setting 1EC=1kJ in my proposal if they most value equivalence with other mods [1]) than to disagree with your own mod about what a kJ is, especially since from what @Akira_R says it is impossible _not_ to disagree with at least one of KSPI and MKS/NFT. [1] And in your proposal, _a_ value of the magic number has the same effect, but it is much less obvious to the user what that value is.

I know RO already adjusts solar performance, and I'd be surprised if it doesn't also adjust battery capacity, so you could look at what they do. If KF has an adjustable conversion factor, it would be able to fit with whatever the CAMREC picks later. :-) Please, please, don't express it in these terms, a flat physical impossibility. Exactly the same thing can be expressed as a conversion factor between electric charge and joules, something that might be a bit more obvious to the user.

I don't know that there's a lot of wiggle room here for the converter to be useful with no specialist, have specialist stars give a meaningful bonus, and not permit over-unity operation with a 5* specialist, but I think it would be worse to render the parts useless for one-Pilot missions. I don't really believe the argument that "lots of people have water purifiers at home, and most of them are not engineers" - they don't turn urine into water, and also they break sometimes and do need an engineer (but the one thing that can't be done in a stockalike mod is to add part breakdown...)

I think these are two different questions. However motors are statted up, the stock EC inconsistencies will remain - but it's still going to be easiest to make a motor's power (whether that's maximum power, power at optimal efficiency, or whatever) a multiplier of the part mass, perhaps using a lower multiplier for tracks, and let the torque be derived from that.

Part of it seems to be that the power is too high. The tiny wheel weighs 50kg but puts out 214 kW? That compares very well to a Tesla's 1.2 kW/kg - let alone the sort of figure one might expect with parts designed for offroad travel. (I suggested 1kW/kg for wheels, 0.75 for tracks). If you're using stats for real-world motors, there may be some confusion there - it's not the power/mass ratio of a motor we need, but the power/mass ratio of a motor+wheel+suspension+brake assembly. (It's driveshaft torque for the Tesla, BTW - since the wheels don't turn at circa 6000 RPM). Stock has never had a very clear value of what a unit of EC is worth. At 1EC = 1kJ, a Probodobodyne OKTO2 draws 1800W, as much as an electric bar fire! Between that and the solar values, we might think an EC is about 100J. (That said, solar panels aren't as absurdly good as your figures suggest - solar energy flux is about 1.3 times higher in space and efficiency is higher (because it's worth spending a lot of money to have a smaller and less massive solar panel to launch)). However, batteries hold 20 EC/kg, which would correspond then to 2 kJ/kg at 1EC=100J, 20 kJ/kg at 1EC=1kW. A Tesla 85kWh (sigh units) battery, conversely, holds 560kJ/kg! (Lithium thionyl chloride batteries, actually used in aerospace, do better, but it's not a rechargable chemistry). Battery masses suggest that an EC might be of the order of 30kJ. Aerospace fuel cells provide c. 700 W/kg. A KSP fuel cell array (different chemistry, mind) provides 0.075 EC/s/kg, which would make an EC about 9.3 kJ. (A SNAP-27 RTG as used on the Apollo missions provided about 3.3 W/kg. A PB-NUK provides about 0.1 EC/s/kg, suggesting an EC is about 300J). (You say "what is 1EC as a stored energy unit, what is 1EC/s as energy flow?" but of course these are the same question). With a factor of 250 between solar performance and battery performance, it'll never be possible to pick a "correct" value; a vehicle that gets realistic endurance on solar power (needs a lot to drive a very light vehicle) will suck its batteries dry in an eyeblink overnight - and a vehicle with realistic endurance on batteries will get absurdly high benefit from solar power. There's a reason Teslas don't have solar roofs. I think this has to be a scalable difficulty setting but the default must be sensible. It might scale from values of 1EC=150J (for realistic performance on solar-powered rovers) to 1EC=30kJ (for realistic battery capacities), and suggest values of 1EC=150J, 1kJ (compatibility with KSPI and realistic performance if you run your vehicle on 1EC=1kJ nuclear reactors from other mods), 10kJ (realistic performance with fuel cells), 30kJ. At 1EC=30kJ, if the overpower is also reduced, a KSP "tiny" wheel draws 50kW, 1.7 EC/s. (This may seem like a lot, but the tiny wheel isn't tiny - it weighs 50kg, over 4 times as much as the entire Sojourner rover). Four of them drawing from a Z-4K battery pack will drain it in ten minutes. (This seems short, but that's going absolutely full power - if a Tesla was running its 85kWh battery pack at a steady 270kW, it would be dry in under twenty minutes.) At 1EC=150J, four "tiny" wheels need 1,333 EC/s, flatly impossible to do on solar. Good - it's not practical to run a full power motor car on solar. If people pick this setting, they'll be building very small automated solar-powered rovers, where the square-cube law works to their advantage (the power of Tweakscaled-down wheels will diminish with the cube of linear dimension, but the available top-deck area of solar will only diminish with the square). Personally, I would put the default at the generous end of the scale. People are much less likely to be unpleasantly surprised by parts working too well! (Ideally, I'd like to see it adjustable in-game - sure, people could use it to "cheat" but they can do that anyway with the debug menu - and it lets the properly hardcore drive different vehicles with "correct" settings each vehicle).

I don't see that that admits of multiple interpretations. This whole "ah, but what if we have 2N kerbals, what is the efficiency then" (answer: the same) business is completely out of left field.

I find this completely remarkable. It was entirely obvious to me. I don't see that "supports N kerbals" admits of any interpretation but the correct one.

Well, no. In general, they don't carry such text, and there is no credible evidence anyone has ever accidentally microwaved a pet. (The persistent urban legend comfortably predates the invention of microwave ovens, no less). I don't think the description should be changed because of some entirely hypothetical population of idiots who enjoy KSP and use TACLS.

That seems entirely an entirely obvious consequence of it supporting up to N kerbals. I cannot imagine why anyone would suppose it would _stop working_ with N+1 kerbals, rather than just not be able to keep up.

"With more Kerbals, your mileage may vary, but it's definitely worse" is frankly gibberish, and I don't see what's wrong with the original statement. "Supports up to N kerbals"; the converter can keep up with the CO2 (etc) generation from up to N kerbals. That seems entirely clear to me.

Huh. Do you have some sort of Supplies to/from TACLS conversion, or just try to meet the requirements of both independently?

I don't think it's useful to compare to the MPL at all, but rather to be comparably effective to the unbroken bits of stock.

This is a fair point, but equally the MPL is so horribly broken, I'd hate to see every mod feel the need to follow suit.

I always thought Stupidity was a bit of a silly joke. Kerbals aren't stupid; they're foolhardy. [1] Their engineering is perfect; their engines always light, their tanks never leak, their airlocks never jam (and don't even take up any space). I'm glad MKS doesn't use it anymore. [1] This is because they are haplodiploid, but that's a joke for another thread...

Steering in reverse, IIRC. If you press left, a tracked vehicle rotates the same way whether it's going forwards, in reverse, or stopped. A wheeled vehicle rotates to the left when going forwards and to the right when going in reverse. What should a half-track do? Probably not have the wheels try and guide you around one way while the tracks try and rotate you the other way, anyway.

Wait, so capped at 30% of the old efficiency?

This is a natural consequence of the square-cube law; double the linear dimensions of the SRB and the mass increases eightfold but the aperture at the base increases only four-fold. You'd expect it to have to be reengineered carefully to preserve the TWR, not just scaled up.

Check it works with a manual install, and submit a PR to CKAN to fix the metadata, or an issue to CKAN reporting that it works.

If you use TACLS and Universal Storage, that contains a useful hydrogen-oxygen fuel cell that is my mainstay for electrically powered roving.

Whoops! I tend to stick to the OX-STAT panels - the deploying ones are just too fragile for vehicles.

A motor doesn't care about the KE of the body it's accelerating, but it does care how fast the shaft is turning, because it has to push it around further every second. I'm not sure how to explain this (and as luck would have this, I am trying to write this comment after a healthy intake of er yeasty beverages) but I should try considering matters without time as a factor. To push with a force of 1N through 2m is clearly twice as much work as pushing with the same force through 1m; to turn the shaft two revolutions exerting a torque of 1Nm is twice as much work as turning it one revolution. Given that, if the shaft revolves twice a second rather than once, and yet we keep pushing it just as hard all the way around, we have done twice as much work that second - twice as much power.

Power is proportional to torque * rpm in the same way work is proportional to force * distance (and hence power pushing something in a straight line increases with the speed of the object). An ideally efficient motor exerting torque at 0 RPM burns no power because it does no work - of course, a real motor burns power from its own internal losses - just as you do no work shoving an immovable object. This is a bit counterintuitive, but what it comes down to is that it takes more energy to shove something (with a given force) a long way than a short one.

If you're willing to go as far as TweakScale, TweakScaling up stock batteries produces - because the small batteries are longer in proportion to their width - thick large radius batteries with huge capacities. Nothing OP - the charge/mass ratio is unchanged, and you could stack a lot of the thin stock batteries to get the same effect, but it keeps down the part count.