Scrambler B

[bernard]

Hi guys,

In the push rod launcher model, where there is the arm that pushes the vehicle and does not touch the ground at the end, does the arm along with the masses be impounded so that they can be measured for the total mass. Meaning, the arm needs to be detached from the device at impound?

If the answer is yes, that the arm also needs to be detached at impound, has any one been able to build this kind successfully? Which is the easiest type to build among all of the options?

Your help is highly appreciated! Thanks!

If it decreases in gravitational potential energy and provides to propel the ETV, then yes it must be detached for impound. If I'm supervising, I wouldn't require that objects of nominal mass (e.g. thin strings, short lengths of tape) be detached for impound if it's inconvenient, but most likely for the push-rod model you'll have things with significant mass. A simple way I can think of is: two eyebolts scewed into the launcher with holes lining up (so a pin can be threaded through), a hole at the end of the push-rod that attaches to the launcher (not the ETV), and take a cotter pin and thread it through these holes such that the push-rod hole is sandwiched between the holes of the two eyebolts.

[dragonfruit35]

Do you have separate weights from the push rod and pendulum? I'd probably say those would count as providing energy, so yes, you would have to impound them. It would have to detach so that the judges could weigh it.

I'm building a pulley launcher, which is semi-easy, but I'd have to say the absolute easiest would be the hammer, though that might break your egg. Scrambler Wiki

[seadog]

With the push rod launcher, is there a high chance that the egg will crack?

How do I go about building a pulley system launcher?

Thanks!!

[nxtscholar]

With the push rod launcher, is there a high chance that the egg will crack?

How do I go about building a pulley system launcher?

Thanks!!

Well..."high" is relative. In general, you would only need to worry about the egg cracking if you manage to launch your car fast enough. Seeing how you're from NJ, I can tell you from previous years that most teams that hit the barrier at states for division C didn't even break their eggs.

I haven't heard of the push rod launcher being too associated with broken eggs, but that's cause most teams last year in NJ didn't use it. Hint: It's not particularly efficient.

As for how to go about building a pulley system, that's something really for you to figure out. Different teams have different number of pulleys and depending on their ETV (egg transport vehicle), position them in different locations. I'd just recommend looking at the pictures NJSO posted online of previous scramblers for a start.

If you need more help, feel free to PM me. I got 4th at states when I did scrambler.

[Shanta]

Hi

Could I get some advice on scrambler design?
For instance, how should I design the ETV? Like a rectangle or a rod in the middle? What materials? I was thinking of balsa and CD wheels, but are there lighter and stronger options?
As for the launcher, I have no idea what to do. I plan to do a spring, but I don't understand the locking mechanisms or the release mechanism. And what materials should I use? I'm thinking of a plywood launcher, but I'm not very sure. Also, are people using photogates to time themselves? Thank you for reading this and thanks in advance!

Shanta

[bernard]

Hi

Could I get some advice on scrambler design?
For instance, how should I design the ETV? Like a rectangle or a rod in the middle? What materials? I was thinking of balsa and CD wheels, but are there lighter and stronger options?
As for the launcher, I have no idea what to do. I plan to do a spring, but I don't understand the locking mechanisms or the release mechanism. And what materials should I use? I'm thinking of a plywood launcher, but I'm not very sure. Also, are people using photogates to time themselves? Thank you for reading this and thanks in advance!

Shanta

There's no single best way to design your device, the components work together to make device that performs well. But here's some thoughts on the ideas you've mentioned.

Rectangle vs. rod in the middle: Seems like the rod in them middle will allow you to save weight. Will you be able to make your rod rigid enough so it is attached securely and doesn't break? Especially since you want to attempt a spring launcher, its more likely your ETV will undergo more stress.

Locking and release for spring launcher: As your mass falls, it will stretch a spring. But if your device is set up like a pulley launcher, rather than stretching the spring much, it'll launch your ETV. So you'll want something to restrain your ETV while the spring is stretched. So that's the locking mechanism. But you can't trigger your device twice to unlock your locking mechanism. So you'll want your mass to somehow trigger the locking mechanism so it releases your ETV (probably right before the mass is at its lowest point). For me understanding the spring launcher and then translating my understanding into a design was the most difficult part, so feel free to ask a lot of questions.

Launcher: Ideally you'll want your launcher to be quite sturdy so the falling mass does not shake it and misalign your device. The wood you get doesn't have to be expensive, but it will be easier to make a stable device with larger cross-sectional area wood.

Photogates for timing: You don't have to predict a time for this event, so would it be worth the time setting up photogates? But they could get precise results if you decide to experiment with factors that affect your time.

[dragonfruit35]

Hi

Could I get some advice on scrambler design?
For instance, how should I design the ETV? Like a rectangle or a rod in the middle? What materials? I was thinking of balsa and CD wheels, but are there lighter and stronger options?
As for the launcher, I have no idea what to do. I plan to do a spring, but I don't understand the locking mechanisms or the release mechanism. And what materials should I use? I'm thinking of a plywood launcher, but I'm not very sure. Also, are people using photogates to time themselves? Thank you for reading this and thanks in advance!

Shanta

With a spring launcher, it's possible balsa might not be strong enough. As long as it's a thick enough piece, you should be fine. I've used CD wheels for Wheeled Vehicle for the past three years, and it's worked well. (Actually, we used Mini CDs, which are lighter and therefore better.) This year, we may transition to using smaller model wheels for more traction and preciseness (that's probably not a word ). Wood, 2x4s for example, is what a lot of teams build their frame out of. It's cheap and fairly easy to put together. My partner and I are experimenting with PVC...

In general, you want your ETV to be as light as possible, but still very sturdy. The lighter it will go, the faster it will go, and thus the better score you'll get, as long as you can stop before the barrier.

[Shanta]

Thx Dragonfruit and Bernard!

I'll build my prototype and will be sure to ask u again lel

for the wood 2x4, im thinking of bass or balsa, I'll pick depending on how much balsa i need to match bass strengh

[Shanta]

WAAAAAAAAAIIIIIIITTTTTT
2X4 for the etv? how? do you cut a hole in it or....? thats going to be really heavy
i like the pvc idea

[nxtscholar]

Hi

Could I get some advice on scrambler design?
For instance, how should I design the ETV? Like a rectangle or a rod in the middle? What materials? I was thinking of balsa and CD wheels, but are there lighter and stronger options?
As for the launcher, I have no idea what to do. I plan to do a spring, but I don't understand the locking mechanisms or the release mechanism. And what materials should I use? I'm thinking of a plywood launcher, but I'm not very sure. Also, are people using photogates to time themselves? Thank you for reading this and thanks in advance!

Shanta

With a spring launcher, it's possible balsa might not be strong enough. As long as it's a thick enough piece, you should be fine. I've used CD wheels for Wheeled Vehicle for the past three years, and it's worked well. (Actually, we used Mini CDs, which are lighter and therefore better.) This year, we may transition to using smaller model wheels for more traction and preciseness (that's probably not a word ). Wood, 2x4s for example, is what a lot of teams build their frame out of. It's cheap and fairly easy to put together. My partner and I are experimenting with PVC...

In general, you want your ETV to be as light as possible, but still very sturdy. The lighter it will go, the faster it will go, and thus the better score you'll get, as long as you can stop before the barrier.

I believe the word you want is precision

Ehhhhh, I'm always a proponent of Murphy's Law. Thick enough is relative and you'll never know exactly when the wood has deformed enough to suddenly break on you. I concur with the previous users (hey bernard ) that rod generally will mean you save more weight as opposed to rectangle. As for materials, well, that depends on your budget. Wood and plastics are generally used but you can't go wrong with carbon fiber for example. Material used for the plywood launcher isn't really as important as the fact that it works.

I had to do some digging around, but as for the locking mechanism, this is the general premise: http://scioly.org/obbarchive/read.php?TID=11350&page=29. Scroll down to see the pictures.