Scioly.org

Oh, cool. Take pictures of it to post later

Easier to build than pneumatics? Maybe?
Part of the appeal of pneumatics is that there's no tension on the brake pad when you are trying to trigger it (like if you were trying to pull a peg out of the springs or something, it is under tension and could jam). With the pneumatics, you flip a switch and it goes.
The obvious downside to the pneumatics is that unless you have the lego version already on-hand, it is a lot harder to acquire something that would work well than it would be to get a set of springs.

I don't know which would work better. I imagine they could both work quite well, if triggered accurately (my problem).

i left my scrambler at school cause i thought i wouldn't get much time to work on it and i was planning on finishing my airplane.
also i'm assuming that the brake pad works better if its in the front of the car?
also if you use notochord's brake system then there would be no pin and it wouldn't jam. and if the "switch" doesn't move so the brake can fall down then that would also mean that the wingnut wouldn't move which also means the axle wouldn't spin thus also stopping it. So if it is under tension and jams then it would stop anyways... right?

Heh...never thought of it that way, yeah...even it if jammed, it would still stop, if not as accurately!

There is still the potential for jamming. You can see the plastic piece attached in front of the wingnut starts deflecting during the slow-motion before it actually triggers the springs, so if your springs were too powerful, the trigger couldn't swing unless your car had more momentum to push the wingnut. The potential is still there, but it could be avoided with good design...like Notochord's

Yeah, brake pad should be in the front instead of the rear for the same reason real cars often have disc brakes in the front and less effective drum brakes in the rear...the weight transfer during braking.

about how big should i make the pad?

Depends entirely on how fast the scrambler is going when you are braking, how heavy the scrambler is, what you plan to line the bottom of the pad with (friction-wise), and where the pad is located, etc.
So...no idea.

Notochord's look very small, but he also used double-sided tape.
I had two 5"x1.5" pads, but used only the anti-slip matting people put under rugs or line tool drawers with.

My scrambler is almost done, I'll get up some pics when it's done.

I'm using a pulley launcher in my scrambler and was wondering if instead of using a string if I could use a rubber band? I realize this is like a spring launcher but I'm not sure if it is legal.

Well, as long as the rubber band is not stretched in any way before you drop the mass, it should be considered legal. Whether or not it will actually work is a different story. I dont see it working but if you manage to get a big enough and strong enough rubber band and you get it work then i dont see anything wrong with it.

Yeah it doesn't work.

also i don't see much of a benefit of a rubber band instead of the string... or maybe its just me
also does anyone have a video of the brake pad in action? like an actual run where the scrambler just stops using the brake pad method? i couldn't find any.