Electric Propellers

[vsully]

On August 13, 2016 at 1:08 AM, JMBuilder said:

Yes, I'm aware that this has been suggested before, but I'm going to expand on it a bit.

It's pretty clear that electric propellers would be very useful for small drones and the like, but why just aircraft? I'm thinking that an electric propeller in KSP would be able to work as an aircraft propeller or as a boat propeller, having special properties that allow it to function better in water than any other form of propulsion. This, or just have two separate types of propellers for aircraft and boats. Propellers could also be set to "push" or "pull" depending on where it was placed on the craft or the situation.

I really do want some boat propellers and maybe even boat parts...

[The_Rocketeer]

17 hours ago, Van Disaster said:

If you can set up a stock rover wheel to default to full forwards, then please demo it ( also how to reverse it! ).

If I knew how to do this I wouldn't post a suggestion, I would do it and post a mod. However, wheel control is a separate input to the yoke controls on WSAD even tho it shares those keys by default - you can rebind the wheels specifically in keybinds. Therefore it seems like it wouldn't be that big a deal to force-override the input.

Either way this really is a major tangent and not really anything to do with anything.

[magnemoe]

23 hours ago, vsully said:

I really do want some boat propellers and maybe even boat parts...

Boat propellers also make sense on an amphibious rover. Yes you could use an electrical propeller like on an swamp boat too but it would be more clunky 

[Overland]

I  wholeheartedly support the idea.. 

I know theres mods for it, but im struggling with just how to propel an RTG powered electric locomotive across water while keeping her more or less stock from original function

water has become such a big part of KSP with the water physics upgrade.. yet we're stuck with jet turbines.. and no stock propellers to speak of..

granted alot has been made of "too much planes!" but stock is good, especially now PS4 and xbox have their version without mods

they cant let the vast oceans of kerbin and the like go unexplored or just explored by the likes of a much slower very low down plane as recent

(and trim works fine for stock rover wheels pegging the throttle)

Edited August 17, 2016 by Overland

[Van Disaster]

On 16/08/2016 at 0:19 PM, pandaman said:

From a pure gameplay perspective we don't need LF powered props for Kerbin or Laythe as we can use jets for that, but electric propulsion could be used there and anywhere else with an atmosphere, so from that perspective alone there is a viable argument in favour of introducing them.

Add to that the 'reality' check that IRL jets don't work under water, but the fact that they currently do in stock is useful as a workaround.  That really should be fixed at some point, but ideally not until we have another solution - like electric props that are configured for use in liquid rather than gas.

Perhaps there is an argument for both EC and LF/O powered propellers.  EC powered ones could be of relatively low power suitable for smaller vessels and LF/O could be bigger with more 'welly'.  Both would be able to be used anywhere as neither necessarily rely on atmospheric oxygen, though maybe the LF/O ones 'could' use just LF if in an oxygen atmosphere.

There is a thing called a water jet it's a rather useful propulsion device to attach to a gas turbine, in fact. A gas turbine won't really work in a submarine, no ( although closed cycle diesels which work submerged without a snort have been around since ww2 ). You could do a turbine powered waterjet by having both air and water intakes, although actually this is one of the edge cases for having seperate power producers & consumers - a real one would spin uselessly out of water, burning trace amounts of fuel, but the combined "engine" would flame out without water.

Fluid propulsion is pretty much all the same - convert stored energy in fuel to thrust by accelerating external mass ( the proportion of thrust provided by the fuel mass isn't generally large ). The existing engine module plus intakes cover that - put resource in, get thrust out - so any prop engines are just a matter of supplying a model & setting up the particular curves. I fully support more stock fluid engines, and I'd like a couple more flags so things are guaranteed to only work spashed down no matter what altitude sea level is in future. Roverdude has a submarine mod with an underwater-only intake, if you read the source to the intake module the problem is trivial to solve ( and in fact is solved, the code is right there! ).

The split-proulsion argument is much bigger & would need a ground up rework of the engine module, and the advantages for general use are a little dubious - what does one engine core with two different propellors gain you over two seperate engine pieces? it's not even saving space in the SPH. The advantages for *specific* uses are there - an amphibious rover with one engine switching between wheels & water props, for instance - which is prime territory for mods.

Edited August 18, 2016 by Van Disaster

[pincushionman]

7 hours ago, Van Disaster said:

…what does one engine core with two different propellors gain you over two seperate engine pieces? it's not even saving space in the SPH. The advantages for *specific* uses are there - an amphibious rover with one engine switching between wheels & water props, for instance - which is prime territory for mods.

Mass distribition. If I have a separate core, I can tune the COM of my plane much more easily.

[Van Disaster]

On 08/18/2016 at 2:13 PM, pincushionman said:

Mass distribition. If I have a separate core, I can tune the COM of my plane much more easily.

Well, it's not like gas turbine cores are usually seperate from any pure mass-acceleration devices ( or even piston engines, although I can think of more than one installation unlike turbines ) - other than helicopters and perhaps boats, although even then the distance isn't far.

The only thing I can think that you really want here is a variable length tailpipe so you can stick an engine a  bit more centrally; the COMoffset setting was meant to help out with that a bit but I don't find that terribly satisfying either. It's surprising how few aircraft have embedded jets though, don't forget the engine would occupy a space you can currently and unrealistically use for fuel.

[pincushionman]

5 hours ago, Van Disaster said:

Well, it's not like gas turbine cores are usually seperate from any pure mass-acceleration devices ( or even piston engines, although I can think of more than one installation unlike turbines ) - other than helicopters and perhaps boats, although even then the distance isn't far.

The only thing I can think that you really want here is a variable length tailpipe so you can stick an engine a  bit more centrally; the COMoffset setting was meant to help out with that a bit but I don't find that terribly satisfying either. It's surprising how few aircraft have embedded jets though, don't forget the engine would occupy a space you can currently and unrealistically use for fuel.

When I proposed the "core" concept, the location of the COM thing hadn't happened yet and all airplanes (particularly small and short ones) were notoriously tail-heavy. The engine COM change did help, but as you said it created the whole "fuel-volume" issue.

And I understand the realistic problems a long jet pipe would cause, but this is a matter of working around the limitations of the LEGO building model. In real life engine designers have more flexibility in the jet pipe shape and length than we do, but more importantly, airframers have a lot more flexibility in the placement and shape of fuel tanks than we do, too. And a system like this would help keep the number of engine choices manageable, too. I'd rather have a few primary engine cores that get "featured up" with effectors than have to search through a long list of engines that are quite similar to get the same flexibility. There could always be a limitation in the effectors that they must be within X meters of the center of a core, particularly for "nozzle" effectors.

But now we're getting more off-topic.

[GoSlash27]

I think it's extremely silly that we don't have props already. There are plenty of good add- ons available.

Best,
-Slashy