Making Propellers: What do you use?

[SchwinnTropius]

I've been studying up on propellers for personal research and possibly modelling my own for use in KSP mods. So for those that model or have modeled propellers, I'd like to know:

How did you model them? Did you use any kind of software to get the blade geometry close to accurate, or did you just make it look close enough?

I know Firespitter allows for motion blurring of the blades in rotation, but I've seen it on other props that I'm not sure use Firespitter; so if it's possible to blur the blades in the rotation without Firespitter, how can it be done?

[SpannerMonkey(smce)]

Hi the blade geometry apart from it's position on the hub is irrelevant, Things such as pitch and chord have no influence on how a propeller  in KSP works because they do not function like propellers,  yes they do accelerate the craft but it's not the blades that are doing it. Like all other KSP engines (aside from mod/stock turboshafts etc) they  provide the acceleration and thrust  via a thrust transform.

The blades do all have to be the same size length etc and balanced around the hub , as an unbalanced mesh will cause vibration.

In Firespitter the prop blur is achieved by a little bit of mesh switching,  the model consists of usually engine body, prop spinner and prop blades,  and a blur disc,  In use when a certain RPM is reached the firespitter plugin switches off the visible blades and switches on the blur disc.

You can use the stock animate throttle for prop simulation. and with the correct animation speeds, some form of automatic blur takes place. 

However I have used both methods recently and to get an accurate simulation of a propeller using the stock modules takes a good amount of fiddling. The firespitter method seems to be much closer to a real world behavior. and easier/quicker to set up

For example using stock engine modules and animate throttle, when you shut the engine down it just stops dead, there's no, what Firespitter calls windmill time, a real prop will rotate a bit after shutdown and turboprops have a long spool down  generally  and only Firespitter ( There may be others )  does this properly

[SchwinnTropius]

I'm aware that the power provided by the engine is solely through engine modules, I intended to ask solely about visual accuracy and what people use to achieve it.

About the stock module blurring: I've used the stock modules to make the prop spin when the engine is activated even at 0 throttle, I just couldn't get the blur at the higher throttle settings. How did you get the blur?

EDIT: just saw what you mean by instantaneous stop on the blades when the "Shutdown Engine" button is clicked, disregard my bit on that.

Edited April 8, 2017 by SchwinnTropius
personal testing result

[SpannerMonkey(smce)]

Hi, well the placement of the blades is fairly simple depending on the number of blades,  even numbers are easier to set up than odd ones though.

So simply create your prop spinner and one blade,  center the spinner and the first blade on one of the axis x/y ,  Set up your modelling apps degree snap to whatever you want , I usually have mine set at 5, clone the first blade and attach it by linking to the hub, do not permanently attach it if you are using firespitter, then simply, in the case of four blades rotate the hub 90deg, if properly linked the first blade will rotate with the hub, clone the first blade again, attach to the hub and rotate 90deg again. Pretty basic stuff really,  it gets a bit trickier with odd number a blades and you need to take a bit of extra care to make sure the center stays in the center.

Spoiler

As for the blur its never as good as the Firespitter version and very much depends on frame rate, but it is passable, just being a matter of trial and error with anim speeds and cfg values

[SchwinnTropius]

Looks interesting. I'll give this all a try. Thank you.

[SchwinnTropius]

As for the blades themselves, how did you shape them?