Ramp jumps. Has anyone done the Astro Spiral?

[Galane]

This!

The jump was developed for a James Bond movie (The Man with the Golden Gun) with an AMC Hornet. For years after, the Joey Chitwood Thrill Show used AMC Javelins to do the jump.

In 2011 Chevrolet did it with a Sonic, calling the jump a kickflip. https://youtu.be/esSRxB_xYCg?t=62 Note the lousy, nearly sideways, landing due to the back end dropping as the car left the ramp. The designers of the stunt either didn't study the original or figured they could do it better.

The original had a way to ensure the car's roll axis would parallel the trajectory so that when the speed and launch were right it would set down smoothly on the other ramp. A couple of clips in the first video show over-rotation and/or jumping too far.

Those all do just one rotation. Try for two or more.

Edited May 17, 2015 by Galane

[Starwhip]

Jumping, you say? You are looking at the reigning champion of the Minmus Rover Jump Challenge!

This one was puny. My current record is 2.1 kilometers. In which time I could do innumerable flips, flatspins, barrel rolls, or other stunts.

Is this a Kerbin-based challenge?

[Galane]

I would say yes to Kerbin based. The idea is to rely on the launch ramp to impart an axial rotation to the vehicle so that when it comes to the landing ramp it's oriented properly to touch down on its wheels and drive off the ramp.

No using reaction wheels or wings and fins or RCS. The idea is to do it with physics, just like the Earthly car jumpers. If you want to try it on Eve, go for it.

[Agate]

The rules should definitely be: on Kerbin, no torque wheels, no thrusters, nothing but wheel power.

[Galane]

Bonus if the vehicle resembles a 70's AMC Hornet or Javelin?

[TheLongRun]

Here is my entry, It's 5 am here so its not my a grade stuff.

[Galane]

Here's a ramp I've built. Dunno if it will work. Will need some way to get it off the runway so a landing ramp can be launched.

screenshot2 by g_alan_e, on Flickr

Download craft file here which also includes a ready to twist flat version, without the approach addition at the front the twisted one has.

[Starwhip]

Back in 0.90.0, you would've been able to move your ramps like this:

[Galane]

A paper on the ramp design by the company that designed it. http://www.mchenrysoftware.com/SpiralJump.pdf

My ramp is way too spirally.

[Xyphos]

Make your ramps with the small, steerable retracting landing gear and tiny ant radial engines then you can simply drive your takeoff ramp off of the runway to launch your landing ramp.

I'm in favor of the idea of multiple ramps and jumping over the mountains to the west of KSC.

Edited May 18, 2015 by Xyphos

[Galane]

New ramp design. Launch from SPH, drive anywhere. Set brakes, decouple, switch to mini-rover, unset brakes and drive out from under. Switch back to ramp and retract gear. Moving the ramp may be easier with the four forward gear's steering unlocked.

The mini rover cannot get up to a high enough speed to spiral off the end of this ramp. It barely gets above 20 m/sec. The ramp can be pushed around with the rover. I thought about putting docking ports on but figured that was extra complication.

http://pastebin.com/E8jQjU5N

screenshot3 by g_alan_e, on Flickr

Edited May 18, 2015 by Galane

[Mad Rocket Scientist]

I'm coming...

[Endersmens]

I have a ramp design. rover at 20 m/s does 3/4th a spin before stopping. (wonder why it stops spinning...)

- - - Updated - - -

Would it count if I did a 180 degree spin? with the 360 roll? Cause that's what its doing right now

[Endersmens]

Can we have some rules for this?

I got it to spin around, bounce off the landing ramp sideways, and then land on its wheels. Did that count? XD

[Galane]

I'm coming...

http://i.imgur.com/kIQs7ja.png

Are those inverted shrouded solar panels on the body? Looks very nice.

Why are people so obsessed with rules? Isn't it enough of a challenge just to make the jump and do it as clean as you can? Hitting a landing ramp without crashing is good. Hitting it straight without skidding sideways is better.

The Chevrolet Sonic jump came pretty close to a crash, so did some of the times the jump was done at stunt shows in the 70's.

Edited May 20, 2015 by Galane

[Mad Rocket Scientist]

Are those inverted shrouded solar panels on the body? Looks very nice.

Why are people so obsessed with rules? Isn't it enough of a challenge just to make the jump and do it as clean as you can? Hitting a landing ramp without crashing is good. Hitting it straight without skidding sideways is better.

The Chevrolet Sonic jump came pretty close to a crash, so did some of the times the jump was done at stunt shows in the 70's.

It looks better than it flies.

[Galane]

It looks better than it flies.

How not to make a jump.

[Endersmens]

How not to make a jump.

Classic mistake...he let his foot off the gas in the air. (Causing forwards rotation as the wheels slow down plus the rotation from the back wheels still being on the ramp after the front wheels left )

Keeping the gas on puts torque Into the wheels, and thanks to newtons law, causes the vehicle to rotate the opposite direction of wheel travel (so nose up in this case )

Effectively using gas and brake in the air, one can control forward and back rotation. (Assuming the vehicle has lots of power )

[Galane]

I think one of the ways the Astro Spiral jump was done was with a collapsing part of the launch ramp on the downward side, set to drop after the front wheel went off. Thus less kick would be given to that back wheel than to the upward side.

The Sonic jump doesn't look like it had any articulated ramp parts and it got a sideways kick as the rear left the ramp.

One possible way to do it without a trick ramp would be to use a "downlock" shock absorber or damper on the downward side of the rear suspension. Basically its one with special valving so it has little resistance to compression but quite a lot to extension. They're often used on drag racing cars so on launch they'll squat and shift weight to the rear easier. "Uplock" one have been used on the front suspension so when the front rises at launch the front suspension can drop fast to keep the wheels in contact with the track for steering.

Any way to alter the up and down suspension damping separately in KSP?

[CaribouGone]

Any way to alter the up and down suspension damping separately in KSP?

in stock, i dont believe so.

Kerbal Foundries Wheels can do such things though.

[Endersmens]

I'll give you guys a hit for ramp design. Only make half the ramp.

I started off with the full ramp, making the spiral was hard, and it didn't kick the rover hard enough.

Then I made two "tracks" for each side of the car, one for the left wheels, one for the right. I made the left track curve up and sideways, and left the right side nearly flat, with a little angle to keep the car going up. This didn't give enough kick either.

So, I've resort to only making the left track. 1 panel wide, just big enough for the left side of the car to go up it. The right side of the car doesn't have a ramp (aside from 1 panel to keep it going upwards)

This really give the car the "kick" it needs to complete a spin. Only problem is, the kick is so violent that its hard to control orientation for landing. It is impossible to do the slow roll that we can IRL because the rotation is slowed by the atmosphere, and the rovers can't have enough mass to keep rotating. (I'm experimenting with adding lots of mass to see if it will help though)

[ttnarg]

Classic mistake...he let his foot off the gas in the air. (Causing forwards rotation as the wheels slow down plus the rotation from the back wheels still being on the ramp after the front wheels left )

Keeping the gas on puts torque Into the wheels, and thanks to newtons law, causes the vehicle to rotate the opposite direction of wheel travel (so nose up in this case )

Effectively using gas and brake in the air, one can control forward and back rotation. (Assuming the vehicle has lots of power )

TIL: Cars have Reaction wheels

Edited May 21, 2015 by ttnarg

[Galane]

The ideal for a ramp to ramp jump is to have the vehicle follow a trajectory as if it was just driving over a small hill, at a speed that in the middle section would just barely have the wheels in contact with the surface. Done right it looks as easy as driving over a small hill. Go too slow or have something wrong with the suspension or takeoff ramp that kicks the back up or nose down and you'll be stopping very quickly into the end of the landing ramp.

Go too fast and you overshoot some to all of the landing ramp, leading to a harder landing or learning what being a pinball feels like.

In other words an ideal jump like that is just a very short sub-orbital flight. Astro Spiral is a very short sub-orbital with a twist.

One failed jump that would have worked if they'd just used the test car was an attempt to jump across a narrow part of the Grand Canyon. The test car was built like a dune buggy and they had ramps setup the exact distance apart as across the canyon. Zip, zip zip! The driver made several test jumps and made it look easy.

Then they proceeded to screw it up by the numbers. The car for the canyon jump had the same chassis but a swoopy fiberglass body with a downturned nose. So they stuck a plastic airdam *on top* of the nose and expected it to counteract the downforce of the sloping nose. They also filled the body with foam so it'd float if it landed in the river and the driver planned to slide up and sit on the back to alter the balance. (And how was he supposed to get back into the seat and belted in, in time for the landing?)

Naturally as soon as it cleared the takeoff ramp it nosed over, the driver bailed out and it was a massive failure on live nationwide TV. They had a car they absolutely knew could jump the distance and stay stable, so WTH did they get stupid and try a car they hadn't put in a wind tunnel nor even tried out on the test jump?

This was on TV, very much pre-WWW. Can't find anything about it online but I watched the live broadcast way back when. Pretty sure it was before Geraldo's "Al Capone's Vault" fiasco that turned out to be an abandoned sidewalk elevator.