Scrambler C

[BobaTeaTastesGood]

Hey everyone! I've been watching all the videos, reading the forums, and scouring the web for design ideas and I think I have come down to a general idea of what I want to do:

-Pulley launcher with high-strength braided fishing line
-A carbon fiber body with a wingnut braking system

For wheels, I was thinking either CDs or Banebots wheels? What do yall think would work better?
Also, how does steering the vehicle work after docking? I've heard some mentions about cutting the frame into two parts but I'm confused on how to go about doing that and maintaining stability.

Thanks in advance!

We also use a carbon fiber and 3D printed frame for the vehicle. For steering, we just leave two of the 3D printed hubs unglued to the carbon rods (whereas all other connection points are properly glued). The tolerance is tight enough so that the vehicle doesn't change with temperature, time, etc. but we can adjust it pretty easily by manually pushing the rods in/out of the 3D printed hubs. Works perfectly fine for us, but definitely not as repeatable or accurate as putting an axle on a hinge (we didn't due this because of weight issues).

For wheels, I would also recommend 3D printing, or at least go for low-diameter wheels. Using non-3D printed wheels like BaneBots will definitely slow you down (at least in our experience) but our accuracy is fairly good.

Fusion 360 is probably the best software to use, but if you're totally new to CAD, then Tinkercad is free and a little more intuitive. You might want to start there and see whether 3D printing is feasible for your design. And if you'd like further information about materials, 3D printing, or design ideas/files, then you can DM me

[pumptato-cat]

BobaTeaTastesGood, have your CF rods ever moved in transportation? Mine are friction fit but tightened with screws. Never had any issues.
sneepity, isn't Fusion360 free? By woodshop I assume you mean use wood for the frame. Warning about this to people reading: wood is quite fiddly to use. It has a natural warp, and is hard to make a good frame with. Obviously there are exceptions to this(last year I was able to get very low scores in MTV with a wood chassis. It was quite a pain to work with, though), but if you have access to a 3D printer go for it. The benefits outweigh the disadvantages by far--I'm never using wood again for a car...

[ckenn4189]

but if you have access to a 3D printer go for it. The benefits outweigh the disadvantages by far--I'm never using wood again for a car...

I actually found out my school has a 3D printer! I also found some files that might work...

[BobaTeaTastesGood]

BobaTeaTastesGood, have your CF rods ever moved in transportation? Mine are friction fit but tightened with screws. Never had any issues.
sneepity, isn't Fusion360 free? By woodshop I assume you mean use wood for the frame. Warning about this to people reading: wood is quite fiddly to use. It has a natural warp, and is hard to make a good frame with. Obviously there are exceptions to this(last year I was able to get very low scores in MTV with a wood chassis. It was quite a pain to work with, though), but if you have access to a 3D printer go for it. The benefits outweigh the disadvantages by far--I'm never using wood again for a car...

Nope, although we do mark their locations with a thin band of tape. A set screw is probably a better idea though.

[sneepity]

BobaTeaTastesGood, have your CF rods ever moved in transportation? Mine are friction fit but tightened with screws. Never had any issues.
sneepity, isn't Fusion360 free? By woodshop I assume you mean use wood for the frame. Warning about this to people reading: wood is quite fiddly to use. It has a natural warp, and is hard to make a good frame with. Obviously there are exceptions to this(last year I was able to get very low scores in MTV with a wood chassis. It was quite a pain to work with, though), but if you have access to a 3D printer go for it. The benefits outweigh the disadvantages by far--I'm never using wood again for a car...

Yeah!! Fusion 360 is free if you got a student license.
https://www.autodesk.com/products/fusion-360/education
try to get this soon, it's 600$ worth of autodesk products

[sneepity]

BobaTeaTastesGood, have your CF rods ever moved in transportation? Mine are friction fit but tightened with screws. Never had any issues.
sneepity, isn't Fusion360 free? By woodshop I assume you mean use wood for the frame. Warning about this to people reading: wood is quite fiddly to use. It has a natural warp, and is hard to make a good frame with. Obviously there are exceptions to this(last year I was able to get very low scores in MTV with a wood chassis. It was quite a pain to work with, though), but if you have access to a 3D printer go for it. The benefits outweigh the disadvantages by far--I'm never using wood again for a car...

Nope, although we do mark their locations with a thin band of tape. A set screw is probably a better idea though.

A set screw or some type of "steering plate" idea is def more repeatable than a friction fit, vibration from several runs can def change up your adjustments.

[pumptato-cat]

I have a couple of questions:

1) Are you allowed to place a target on the track during aiming? I'm assuming so(because how else would you aim at a target if you can't even see it?...). Does anyone know an official answer? I think 6g covers this but am not sure.
2) When does the 8-minute time period start? Rules say "to set up and start 2 runs"--I'm assuming they start timing the moment you put your car and launcher down? Or is it when you walk onto the track?

[BobaTeaTastesGood]

I have a couple of questions:

1) Are you allowed to place a target on the track during aiming? I'm assuming so(because how else would you aim at a target if you can't even see it?...). Does anyone know an official answer? I think 6g covers this but am not sure.
2) When does the 8-minute time period start? Rules say "to set up and start 2 runs"--I'm assuming they start timing the moment you put your car and launcher down? Or is it when you walk onto the track?

1. I believe you are allowed to as long as you remove it before launching. This would fall under section 2a as an alignment device

2. At least in my experience, the supervisors will start timing once you set your devices down. The time taken to tape the egg on has also counted for time (which affects more teams than you would think)

[knightmoves]

2. At least in my experience, the supervisors will start timing once you set your devices down. The time taken to tape the egg on has also counted for time (which affects more teams than you would think)

I've seen ES do various different things. I've seen ES start the time when you set your device down. I've seen ES measure your device beside the track, and then tell you that they're going to start the timer. It's clear that the set-up time shouldn't include the time required to retrieve your build from impound and carry it to the track area, but exactly when it starts isn't defined.

[pumptato-cat]

Okay-Thank you so much everyone! I think I'll just do the best I can, there really isn't a point in arguing with the ES and it's their choice on how to record... Hopefully I get a nice ES for regionals