Scrambler B

[kendreaditya]

Does anyone have any suggestion on how to align the propulsion system?

[SPP SciO]

In the spring and pulley launcher, does anyone have ideas as to how you would get the ETV and the string to separate. And anyone have ideas what material you could use for the string. '

I think I may be interpreting your question a little differently than above. With any pulley launcher - whether you just use string, or you add some elastic material for a speed boost - you'll need to get a smooth, reliable release each launch.

We've found that the simplest thing is a small (< 5cm) vertical dowel mounted on the rear of the vehicle, and a key ring loop tied to the end of the string. Slide the ring over the dowel before launch, and as the weight falls (or after the trigger is activated, with elastic), the ring will pull the vehicle forwards, until it reaches the front of the launcher. The string will fly upwards (hence: safety goggles!) and the car will pull forward.

Of course, you'll soon find that the egg backstop gets in the way, but if you experiment, you'll find ways to mechanically direct the string to your liking.

We've also found that the simplest strategy for avoiding the bucket is building a slight offset into the front axle, and fixing it there. The only adjustment is made to the launch angle (and the number of axle rotations of course). Draw a giant protractor on a piece of chart paper and tape it to the floor under the launcher while testing.

[rajofin]

Hi - The rules mention that no flexible material may be used to make ETV but is it legal to use rubber sleeve for ETV wheels? This is our first time but my friend who has done this in past mentioned they saw several ETVs with rubber sleeves on their CD type wheels. Any help is appreciated. Thank you.

Also, do you have sample of practice logs? I couldn't find a template that we should use.

[SPP SciO]

Hi - The rules mention that no flexible material may be used to make ETV but is it legal to use rubber sleeve for ETV wheels? This is our first time but my friend who has done this in past mentioned they saw several ETVs with rubber sleeves on their CD type wheels. Any help is appreciated. Thank you.

Also, do you have sample of practice logs? I couldn't find a template that we should use.

The "rigid, non-flexible material" refers to the chassis - basically, you can't design the vehicle with "crumple zones" like a car would have to protect the egg. The goal is to stop the car before the barrier, not to use the barrier as a brake and build a cushion to protect the egg. So, yes, rubber on the CD wheels (balloons are popular) is legal and will give you useful extra friction.

As for practice logs, our teams used Launch Angle and # of Axle Rotations as their independent variables, and Forward Distance and Left/Right Off Center distance as their dependent variables.

[smrt1337]

Does anyone have any suggestion on how to align the propulsion system?

I'm assuming you mean the angle of the launcher. You could use a scope (for guns etc.) and align the crosshairs with some sort of marker you place down the track. You would adjust the launch angle by moving the marker.

[mapr]

Regarding the tools for aiming - could one use a gun sight with a laser pointer built in ? Or does this violate 2.j?
Thanks

[dragonfruit35]

Regarding the tools for aiming - could one use a gun sight with a laser pointer built in ? Or does this violate 2.j?
Thanks

You could use a sight, but the laser would be illegal, as it is an electrical device.

[mapr]

Makes sense - just wanted to be sure.
Thank you

[smrt1337]

Regarding the tools for aiming - could one use a gun sight with a laser pointer built in ? Or does this violate 2.j?
Thanks

You could use a sight, but the laser would be illegal, as it is an electrical device.

However, be careful... there are some gun sights that illuminated, and those are illegal as they count as electronics.

[Mp3nguin__]

What is the longest anyone has seen a track this year for Scrambler? Thanks!