What does your grav bike look like?

[coliver988]

Problem is, if it is one, is that local gravity fields vary.

And fractional gravities, whether on gravitational motors, lifters, or manoeuvre drive, need to be tuned to that field, usually in the Mars to Terra range.

though I've wondered if the generated grav field is always proportional to the local gravity. That is, the higher the local gravity is, the stronger the generated reaction force is. So that you will always get the same acceleration regardless of local gravity. Of course, this does have odd effects at extreme ranges: black holes, for instance But it was a thought so I did not have to worry about localized tuning of grav engines.

 

[Spinward Flow]

though I've wondered if the generated grav field is always proportional to the local gravity. That is, the higher the local gravity is, the stronger the generated reaction force is. So that you will always get the same acceleration regardless of local gravity. Of course, this does have odd effects at extreme ranges: black holes, for instance But it was a thought so I did not have to worry about localized tuning of grav engines.

Simplest solution to the "problem" is that anti-grav works based on Mass, not on Weight.
That way, anti-grav propulsion/thrust will achieve the same acceleration of a given rest mass regardless of the local gravity field conditions.

For gaming purposes, that means that if you can get a performance of 10m/s² acceleration under world gravity well conditions of 1G (Terra nominal) ... then you'll STILL get that same performance of 10m/s² acceleration yield under different local gravity conditions (Luna, Mars, etc.). The difference is that in lower gravity conditions, you need to "spend" less of your anti-grav thrust vector on "lift" to maintain buoyancy/altitude over surface and have more "thrust" fraction left over for lateral movement/travel.

 

[Nightwind1]

I figure it's pretty similar to this:
View attachment 6248
EDIT: I thought it would put a picture up.
MOD EDIT: Image Inserted

Rob Caswell for the win!

 

[Rupert]

The way I see it, using TNE/FF&S's assumption that contra-grav neutralises about 99% of gravitational attraction, a fully loaded grav bike massing about 1.4 tonnes (TNE's numbers) thus weighs about 14 kg on Earth. It displaces about 1.4kg of air so it's not buoyant, but it takes only a little vertical thrust or aerodynamic lift to allow it to fly. Given the TNE grav bike has a 700kg HEPlaR thruster (don't stand behind it!), the biggest issue is probably running the thing at low enough power to just hover (well, aside from how the C-G system is allowing perpetual motion machines and smashing the Laws of Thermodynamics into little itty bits).

 

[whartung]

Given the TNE grav bike has a 700kg HEPlaR thruster (don't stand behind it!)

That's the fundamental issue.

Making these devices safe for civilized life.

You still need acceleration to counter the actual mass of the vehicle, regardless of how hard gravity is tugging on it

You can get by with less, but if it's a thruster of any kind, there's going to be, well, thrust to deal with. Especially if it's fusion out gassing by products.

Modern gas and electric vehicles do require external thrust, relying on traction and radiators for the waste heat. But, they don't fly either.

That earlier drawing of the Flying Brookstick with the pivoting fans is probably about as sane and you're going to get, but I bet what they lack in "blasting nearby pedestrians off their feet" power, they make up for in just raw noise.

 

[Rupert]

That earlier drawing of the Flying Brookstick with the pivoting fans is probably about as sane and you're going to get, but I bet what they lack in "blasting nearby pedestrians off their feet" power, they make up for in just raw noise.

As shrouded props they'll be less noisy than just most other methods, but at full power they're probably not quiet.

 

[kilemall]

Simplest solution to the "problem" is that anti-grav works based on Mass, not on Weight.
That way, anti-grav propulsion/thrust will achieve the same acceleration of a given rest mass regardless of the local gravity field conditions.

For gaming purposes, that means that if you can get a performance of 10m/s² acceleration under world gravity well conditions of 1G (Terra nominal) ... then you'll STILL get that same performance of 10m/s² acceleration yield under different local gravity conditions (Luna, Mars, etc.). The difference is that in lower gravity conditions, you need to "spend" less of your anti-grav thrust vector on "lift" to maintain buoyancy/altitude over surface and have more "thrust" fraction left over for lateral movement/travel.

That’s how CT Striker operates.

 

[Condottiere]

There are many likely solutions.

But, I think it might be layered.

You have two types of gravitational motors installed.

The lifters neutralize the local gravity field.

Then, you have separate thrusters that give acceleration and direction.

 

[Grav_Moped]

Problem is, if it is one, is that local gravity fields vary.

And fractional gravities, whether on gravitational motors, lifters, or manoeuvre drive, need to be tuned to that field, usually in the Mars to Terra range.

though I've wondered if the generated grav field is always proportional to the local gravity. That is, the higher the local gravity is, the stronger the generated reaction force is. So that you will always get the same acceleration regardless of local gravity. Of course, this does have odd effects at extreme ranges: black holes, for instance But it was a thought so I did not have to worry about localized tuning of grav engines.

That's what I was talking about. The early (in publication history) version of grav vehicles worked exactly that way, if only because they hadn't really thought about it that much.

Striker and so forth are what they ended up with when they did put some thought into it. Unfortunately, backporting Striker's design sequence onto LBB2-3 vehicles yeilds quirky results.

 

[BlackBat242]

As I do my thinking about these things using FF&S, I assume contra-grav produces no thrust. It just makes everything in a field (either a simple ellipsoid shape or one bounded by a sealed hull) weigh very little (though mass is retained). So alternate sources of thrust and directional control are required to move and to control direction and attitude.

As for what they look like - it depends on manufacturer and exact intended role. Some look like the 'IISS Grav Bike' image above. Others like:
View attachment 6245

And, for a more radical appearance, some are the 'broomsticks' of the Reformation Coalition:
View attachment 6246

Or this (made by a venerable Terran firm):